[PATCH v5] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

From: Daeho Jeong 

I've added new sysfs nodes to show runtime compression stat since mount.
compr_written_block - show the block count written after compression
compr_saved_block - show the saved block count with compression
compr_new_inode - show the count of inode newly enabled for compression

Signed-off-by: Daeho Jeong 
---
v2: thanks to kernel test robot , fixed compile issue
related to kernel config
v3: changed sysfs nodes' names and made them runtime stat, not
persistent on disk
v4: changed sysfs nodes' desctiption
v5: changed not to use atomic values
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 24 
 fs/f2fs/compress.c  |  1 +
 fs/f2fs/f2fs.h  | 19 +
 fs/f2fs/sysfs.c | 38 +
 4 files changed, 82 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index cbeac1bebe2f..ddd4bd6116fc 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -409,3 +409,27 @@ Description:   Give a way to change checkpoint merge 
daemon's io priority.
I/O priority "3". We can select the class between "rt" and "be",
and set the I/O priority within valid range of it. "," delimiter
is necessary in between I/O class and priority number.
+
+What:  /sys/fs/f2fs//compr_written_block
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the block count written after compression since mount. Note
+   that when the compressed blocks are deleted, this count doesn't
+   decrease. If you write "0" here, you can initialize
+   compr_written_block and compr_saved_block to "0".
+
+What:  /sys/fs/f2fs//compr_saved_block
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the saved block count with compression since mount. Note
+   that when the compressed blocks are deleted, this count doesn't
+   decrease. If you write "0" here, you can initialize
+   compr_written_block and compr_saved_block to "0".
+
+What:  /sys/fs/f2fs//compr_new_inode
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the count of inode newly enabled for compression since 
mount.
+   Note that when the compression is disabled for the files, this 
count
+   doesn't decrease. If you write "0" here, you can initialize
+   compr_new_inode to "0".
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 77fa342de38f..3c9d797dbdd6 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1353,6 +1353,7 @@ static int f2fs_write_compressed_pages(struct 
compress_ctx *cc,
if (fio.compr_blocks)
f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
+   add_compr_block_stat(inode, cc->nr_cpages);
 
set_inode_flag(cc->inode, FI_APPEND_WRITE);
if (cc->cluster_idx == 0)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e2d302ae3a46..ae7e08aa7d87 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1623,6 +1623,11 @@ struct f2fs_sb_info {
 #ifdef CONFIG_F2FS_FS_COMPRESSION
struct kmem_cache *page_array_slab; /* page array entry */
unsigned int page_array_slab_size;  /* default page array slab size 
*/
+
+   /* For runtime compression statistics */
+   u64 compr_written_block;
+   u64 compr_saved_block;
+   u32 compr_new_inode;
 #endif
 };
 
@@ -3955,6 +3960,18 @@ int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi);
 void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi);
 int __init f2fs_init_compress_cache(void);
 void f2fs_destroy_compress_cache(void);
+#define inc_compr_inode_stat(inode)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   sbi->compr_new_inode++; \
+   } while (0)
+#define add_compr_block_stat(inode, blocks)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   int diff = F2FS_I(inode)->i_cluster_size - blocks;  \
+   sbi->compr_written_block += blocks; \
+   sbi->compr_saved_block += diff; \
+   } while (0)
 #else
 static inline bool f2fs_is_compressed_page(struct page *page) { return false; }
 stat

Re: [PATCH v4] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

2021년 3월 12일 (금) 오후 11:45, Greg KH 님이 작성:
>
> A: http://en.wikipedia.org/wiki/Top_post
> Q: Were do I find info about this thing called top-posting?
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?
>
> A: No.
> Q: Should I include quotations after my reply?
>
> http://daringfireball.net/2007/07/on_top
>

Thanks for letting me know this!

>
> On Fri, Mar 12, 2021 at 11:37:29PM +0900, Daeho Jeong wrote:
> > As you can see, if we're doing like the below.
> >
> > sbi->compr_written_block += blocks;
> >
> > Let's assume the initial value as 0.
> >
> >  
> > sbi->compr_written_block = 0;
> >
> > sbi->compr_written_block = 0;
> > +blocks(3);
> >+ blocks(2);
> > sbi->compr_written_block = 3;
> >
> > sbi->compr_written_block = 2;
> >
> > Finally, we end up with 2, not 5.
> >
> > As more threads are participating it, we might miss more counting.
>
> Are you sure?  Isn't adding a number something that should happen in a
> "safe" way?
>
> And if you miss 2 blocks, who cares?  What is so critical about these
> things that you take the cache flush of 2 atomic writes just for a
> debugging statistic?
>
> Why not just take 1 lock for everything if it's so important to get
> these "correct"?
>
> What is the performance throughput degradation of adding 2 atomic writes
> to each time you write a block?
>
> But really, will you ever notice missing a few, even if that could be
> possible on your cpu (and I strongly doubt most modern cpus will miss
> this...)
>
> But this isn't my code, I just hate seeing atomic variables used for
> silly things like debugging stats when they do not seem to be really
> needed.  So if you want to keep them, go ahead, but realize that the
> number you are reading has nothing to do with being "atomic" at all.
>
> thanks,
>

I agree that missing number would be extremely few and the overhead of
updating the numbers would be quite bad.

Thanks for your valuable comments. :)

> greg k-h

Re: [PATCH v4] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

So, do you want we protect the values here with spin_lock and just
read without spin_lock in sysfs read part?

2021년 3월 12일 (금) 오후 11:37, Daeho Jeong 님이 작성:
>
> As you can see, if we're doing like the below.
>
> sbi->compr_written_block += blocks;
>
> Let's assume the initial value as 0.
>
>  
> sbi->compr_written_block = 0;
>
> sbi->compr_written_block = 0;
> +blocks(3);
>+ blocks(2);
> sbi->compr_written_block = 3;
>
> sbi->compr_written_block = 2;
>
> Finally, we end up with 2, not 5.
>
> As more threads are participating it, we might miss more counting.
>
> 2021년 3월 12일 (금) 오후 11:04, Greg KH 님이 작성:
> >
> > On Fri, Mar 12, 2021 at 10:56:13PM +0900, Daeho Jeong wrote:
> > > Thanks for suggesting me sysfs_emit().
> > >
> > > For atomic values, actually, those are needed for writer part, not reader.
> > >
> > > +#define add_compr_block_stat(inode, blocks)\
> > > +   do {\
> > > +   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
> > > +   int diff = F2FS_I(inode)->i_cluster_size - blocks;  \
> > > +   atomic64_add(blocks, &sbi->compr_written_block);\
> > > +   atomic64_add(diff, &sbi->compr_saved_block);\
> > > +   } while (0)
> > >
> > > I needed a protection here, because they might be updated in the race 
> > > condition.
> >
> > Why?  What are you trying to protect from "racing" here?
> >
> > thanks,
> >
> > greg k-h

Re: [PATCH v4] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

As you can see, if we're doing like the below.

sbi->compr_written_block += blocks;

Let's assume the initial value as 0.

 
sbi->compr_written_block = 0;

sbi->compr_written_block = 0;
+blocks(3);
   + blocks(2);
sbi->compr_written_block = 3;

sbi->compr_written_block = 2;

Finally, we end up with 2, not 5.

As more threads are participating it, we might miss more counting.

2021년 3월 12일 (금) 오후 11:04, Greg KH 님이 작성:
>
> On Fri, Mar 12, 2021 at 10:56:13PM +0900, Daeho Jeong wrote:
> > Thanks for suggesting me sysfs_emit().
> >
> > For atomic values, actually, those are needed for writer part, not reader.
> >
> > +#define add_compr_block_stat(inode, blocks)\
> > +   do {\
> > +   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
> > +   int diff = F2FS_I(inode)->i_cluster_size - blocks;  \
> > +   atomic64_add(blocks, &sbi->compr_written_block);\
> > +   atomic64_add(diff, &sbi->compr_saved_block);\
> > +   } while (0)
> >
> > I needed a protection here, because they might be updated in the race 
> > condition.
>
> Why?  What are you trying to protect from "racing" here?
>
> thanks,
>
> greg k-h

Re: [PATCH v4] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

Thanks for suggesting me sysfs_emit().

For atomic values, actually, those are needed for writer part, not reader.

+#define add_compr_block_stat(inode, blocks)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   int diff = F2FS_I(inode)->i_cluster_size - blocks;  \
+   atomic64_add(blocks, &sbi->compr_written_block);\
+   atomic64_add(diff, &sbi->compr_saved_block);\
+   } while (0)

I needed a protection here, because they might be updated in the race condition.

2021년 3월 12일 (금) 오후 9:39, Greg KH 님이 작성:
>
> On Fri, Mar 12, 2021 at 09:25:31PM +0900, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > I've added new sysfs nodes to show runtime compression stat since mount.
> > compr_written_block - show the block count written after compression
> > compr_saved_block - show the saved block count with compression
> > compr_new_inode - show the count of inode newly enabled for compression
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> > v2: thanks to kernel test robot , fixed compile issue
> > related to kernel config
> > v3: changed sysfs nodes' names and made them runtime stat, not
> > persistent on disk
> > v4: changed sysfs nodes' desctiption
> > ---
> >  Documentation/ABI/testing/sysfs-fs-f2fs | 24 ++
> >  fs/f2fs/compress.c  |  1 +
> >  fs/f2fs/f2fs.h  | 19 
> >  fs/f2fs/super.c |  7 +++
> >  fs/f2fs/sysfs.c | 58 +
> >  5 files changed, 109 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
> > b/Documentation/ABI/testing/sysfs-fs-f2fs
> > index cbeac1bebe2f..ddd4bd6116fc 100644
> > --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> > @@ -409,3 +409,27 @@ Description: Give a way to change checkpoint merge 
> > daemon's io priority.
> >   I/O priority "3". We can select the class between "rt" and 
> > "be",
> >   and set the I/O priority within valid range of it. "," 
> > delimiter
> >   is necessary in between I/O class and priority number.
> > +
> > +What:/sys/fs/f2fs//compr_written_block
> > +Date:March 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Show the block count written after compression since mount. 
> > Note
> > +     that when the compressed blocks are deleted, this count 
> > doesn't
> > + decrease. If you write "0" here, you can initialize
> > + compr_written_block and compr_saved_block to "0".
> > +
> > +What:/sys/fs/f2fs//compr_saved_block
> > +Date:March 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Show the saved block count with compression since mount. Note
> > + that when the compressed blocks are deleted, this count 
> > doesn't
> > + decrease. If you write "0" here, you can initialize
> > + compr_written_block and compr_saved_block to "0".
> > +
> > +What:/sys/fs/f2fs//compr_new_inode
> > +Date:March 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Show the count of inode newly enabled for compression since 
> > mount.
> > + Note that when the compression is disabled for the files, 
> > this count
> > + doesn't decrease. If you write "0" here, you can initialize
> > + compr_new_inode to "0".
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 77fa342de38f..3c9d797dbdd6 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -1353,6 +1353,7 @@ static int f2fs_write_compressed_pages(struct 
> > compress_ctx *cc,
> >   if (fio.compr_blocks)
> >   f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, 
> > false);
> >   f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
> > + add_compr_block_stat(inode, cc->nr_cpages);
> >
> >   set_inode_flag(cc->inode, FI_APPEND_WRITE);
> >   if (cc->cluster_idx == 0)
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index e2d302ae3a46..2c989f8caf05 1

[PATCH v4] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

From: Daeho Jeong 

I've added new sysfs nodes to show runtime compression stat since mount.
compr_written_block - show the block count written after compression
compr_saved_block - show the saved block count with compression
compr_new_inode - show the count of inode newly enabled for compression

Signed-off-by: Daeho Jeong 
---
v2: thanks to kernel test robot , fixed compile issue
related to kernel config
v3: changed sysfs nodes' names and made them runtime stat, not
persistent on disk
v4: changed sysfs nodes' desctiption
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 24 ++
 fs/f2fs/compress.c  |  1 +
 fs/f2fs/f2fs.h  | 19 
 fs/f2fs/super.c |  7 +++
 fs/f2fs/sysfs.c | 58 +
 5 files changed, 109 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index cbeac1bebe2f..ddd4bd6116fc 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -409,3 +409,27 @@ Description:   Give a way to change checkpoint merge 
daemon's io priority.
I/O priority "3". We can select the class between "rt" and "be",
and set the I/O priority within valid range of it. "," delimiter
is necessary in between I/O class and priority number.
+
+What:  /sys/fs/f2fs//compr_written_block
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the block count written after compression since mount. Note
+   that when the compressed blocks are deleted, this count doesn't
+   decrease. If you write "0" here, you can initialize
+   compr_written_block and compr_saved_block to "0".
+
+What:  /sys/fs/f2fs//compr_saved_block
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the saved block count with compression since mount. Note
+   that when the compressed blocks are deleted, this count doesn't
+   decrease. If you write "0" here, you can initialize
+   compr_written_block and compr_saved_block to "0".
+
+What:  /sys/fs/f2fs//compr_new_inode
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the count of inode newly enabled for compression since 
mount.
+   Note that when the compression is disabled for the files, this 
count
+   doesn't decrease. If you write "0" here, you can initialize
+   compr_new_inode to "0".
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 77fa342de38f..3c9d797dbdd6 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1353,6 +1353,7 @@ static int f2fs_write_compressed_pages(struct 
compress_ctx *cc,
if (fio.compr_blocks)
f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
+   add_compr_block_stat(inode, cc->nr_cpages);
 
set_inode_flag(cc->inode, FI_APPEND_WRITE);
if (cc->cluster_idx == 0)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e2d302ae3a46..2c989f8caf05 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1623,6 +1623,11 @@ struct f2fs_sb_info {
 #ifdef CONFIG_F2FS_FS_COMPRESSION
struct kmem_cache *page_array_slab; /* page array entry */
unsigned int page_array_slab_size;  /* default page array slab size 
*/
+
+   /* For runtime compression statistics */
+   atomic64_t compr_written_block;
+   atomic64_t compr_saved_block;
+   atomic_t compr_new_inode;
 #endif
 };
 
@@ -3955,6 +3960,18 @@ int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi);
 void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi);
 int __init f2fs_init_compress_cache(void);
 void f2fs_destroy_compress_cache(void);
+#define inc_compr_inode_stat(inode)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   atomic_inc(&sbi->compr_new_inode);  \
+   } while (0)
+#define add_compr_block_stat(inode, blocks)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   int diff = F2FS_I(inode)->i_cluster_size - blocks;  \
+   atomic64_add(blocks, &sbi->compr_written_block);\
+   atomic64_add(diff, &sbi->compr_saved_block);\
+   } while (0)
 #else
 static inline bool f2fs_is_compressed_page(struct page *page) { return fa

Re: [f2fs-dev] [PATCH v3] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

We're going to use these just accumulating numbers and periodically
gather and reset them.
Yes, I will add the description like you suggested.

Thanks,

2021년 3월 12일 (금) 오후 6:50, Chao Yu 님이 작성:
>
> On 2021/3/11 10:32, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > I've added new sysfs nodes to show runtime compression stat since mount.
> > compr_written_block - show the block count written after compression
> > compr_saved_block - show the saved block count with compression
> > compr_new_inode - show the count of inode newly enabled for compression
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> > v2: thanks to kernel test robot , fixed compile issue
> >  related to kernel config.
> > v3: changed sysfs nodes' names and made them runtime stat, not
> >  persistent on disk
> > ---
> >   Documentation/ABI/testing/sysfs-fs-f2fs | 20 +
> >   fs/f2fs/compress.c  |  1 +
> >   fs/f2fs/f2fs.h  | 19 
> >   fs/f2fs/super.c |  7 +++
> >   fs/f2fs/sysfs.c | 58 +
> >   5 files changed, 105 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
> > b/Documentation/ABI/testing/sysfs-fs-f2fs
> > index cbeac1bebe2f..f2981eb319cb 100644
> > --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> > @@ -409,3 +409,23 @@ Description: Give a way to change checkpoint merge 
> > daemon's io priority.
> >   I/O priority "3". We can select the class between "rt" and 
> > "be",
> >   and set the I/O priority within valid range of it. "," 
> > delimiter
> >   is necessary in between I/O class and priority number.
> > +
> > +What:/sys/fs/f2fs//compr_written_block
> > +Date:March 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Show the block count written after compression since mount.
> > + If you write "0" here, you can initialize compr_written_block 
> > and
> > + compr_saved_block to "0".
> > +
> > +What:/sys/fs/f2fs//compr_saved_block
> > +Date:March 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Show the saved block count with compression since mount.
> > + If you write "0" here, you can initialize compr_written_block 
> > and
> > + compr_saved_block to "0".
> > +
> > +What:/sys/fs/f2fs//compr_new_inode
> > +Date:March 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Show the count of inode newly enabled for compression since 
> > mount.
> > + If you write "0" here, you can initialize compr_new_inode to 
> > "0".
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 77fa342de38f..3c9d797dbdd6 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -1353,6 +1353,7 @@ static int f2fs_write_compressed_pages(struct 
> > compress_ctx *cc,
> >   if (fio.compr_blocks)
> >   f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, 
> > false);
> >   f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
> > + add_compr_block_stat(inode, cc->nr_cpages);
>
> If compressed cluster was overwritten as normal cluster, compr_saved_block 
> value
> won't be decreased, is it fine?
>
> >
> >   set_inode_flag(cc->inode, FI_APPEND_WRITE);
> >   if (cc->cluster_idx == 0)
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index e2d302ae3a46..2c989f8caf05 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -1623,6 +1623,11 @@ struct f2fs_sb_info {
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> >   struct kmem_cache *page_array_slab; /* page array entry */
> >   unsigned int page_array_slab_size;  /* default page array slab 
> > size */
> > +
> > + /* For runtime compression statistics */
> > + atomic64_t compr_written_block;
> > + atomic64_t compr_saved_block;
> > + atomic_t compr_new_inode;
> >   #endif
> >   };
> >
> > @@ -3955,6 +3960,18 @@ int f2fs_init_page_array_cache(struct f2fs_sb_info 
> > *sbi);
> >   void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi);
> >   int __init f2fs_init_c

[PATCH v3] f2fs: add sysfs nodes to get runtime compression stat

[Daeho Jeong]

From: Daeho Jeong 

I've added new sysfs nodes to show runtime compression stat since mount.
compr_written_block - show the block count written after compression
compr_saved_block - show the saved block count with compression
compr_new_inode - show the count of inode newly enabled for compression

Signed-off-by: Daeho Jeong 
---
v2: thanks to kernel test robot , fixed compile issue
related to kernel config.
v3: changed sysfs nodes' names and made them runtime stat, not
persistent on disk
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 20 +
 fs/f2fs/compress.c  |  1 +
 fs/f2fs/f2fs.h  | 19 
 fs/f2fs/super.c |  7 +++
 fs/f2fs/sysfs.c | 58 +
 5 files changed, 105 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index cbeac1bebe2f..f2981eb319cb 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -409,3 +409,23 @@ Description:   Give a way to change checkpoint merge 
daemon's io priority.
I/O priority "3". We can select the class between "rt" and "be",
and set the I/O priority within valid range of it. "," delimiter
is necessary in between I/O class and priority number.
+
+What:  /sys/fs/f2fs//compr_written_block
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the block count written after compression since mount.
+   If you write "0" here, you can initialize compr_written_block 
and
+   compr_saved_block to "0".
+
+What:      /sys/fs/f2fs//compr_saved_block
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the saved block count with compression since mount.
+   If you write "0" here, you can initialize compr_written_block 
and
+   compr_saved_block to "0".
+
+What:  /sys/fs/f2fs//compr_new_inode
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show the count of inode newly enabled for compression since 
mount.
+   If you write "0" here, you can initialize compr_new_inode to 
"0".
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 77fa342de38f..3c9d797dbdd6 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1353,6 +1353,7 @@ static int f2fs_write_compressed_pages(struct 
compress_ctx *cc,
if (fio.compr_blocks)
f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
+   add_compr_block_stat(inode, cc->nr_cpages);
 
set_inode_flag(cc->inode, FI_APPEND_WRITE);
if (cc->cluster_idx == 0)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e2d302ae3a46..2c989f8caf05 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1623,6 +1623,11 @@ struct f2fs_sb_info {
 #ifdef CONFIG_F2FS_FS_COMPRESSION
struct kmem_cache *page_array_slab; /* page array entry */
unsigned int page_array_slab_size;  /* default page array slab size 
*/
+
+   /* For runtime compression statistics */
+   atomic64_t compr_written_block;
+   atomic64_t compr_saved_block;
+   atomic_t compr_new_inode;
 #endif
 };
 
@@ -3955,6 +3960,18 @@ int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi);
 void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi);
 int __init f2fs_init_compress_cache(void);
 void f2fs_destroy_compress_cache(void);
+#define inc_compr_inode_stat(inode)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   atomic_inc(&sbi->compr_new_inode);  \
+   } while (0)
+#define add_compr_block_stat(inode, blocks)\
+   do {\
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);\
+   int diff = F2FS_I(inode)->i_cluster_size - blocks;  \
+   atomic64_add(blocks, &sbi->compr_written_block);\
+   atomic64_add(diff, &sbi->compr_saved_block);\
+   } while (0)
 #else
 static inline bool f2fs_is_compressed_page(struct page *page) { return false; }
 static inline bool f2fs_is_compress_backend_ready(struct inode *inode)
@@ -3983,6 +4000,7 @@ static inline int f2fs_init_page_array_cache(struct 
f2fs_sb_info *sbi) { return
 static inline void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi) { }
 static inline int __init f2fs_init_compress_cache(void) { return 0; }
 static inline void f2fs_destroy

Re: [f2fs-dev] [PATCH v2] f2fs: add sysfs nodes to get accumulated compression info

[Daeho Jeong]

We've reconsidered this feature and decided to get just runtime info
of them, not persistent on disk.
I am re-writing it.

Thanks,

2021년 3월 10일 (수) 오전 10:31, Chao Yu 님이 작성:
>
> On 2021/3/9 21:00, Daeho Jeong wrote:
> > 2021년 3월 9일 (화) 오후 6:22, Chao Yu 님이 작성:
> >>
> >> On 2021/3/5 10:24, Daeho Jeong wrote:
> >>> From: Daeho Jeong 
> >>>
> >>> Added acc_compr_inodes to show accumulated compressed inode count and
> >>> acc_compr_blocks to show accumulated secured block count with
> >>
> >> I noticed that these stat numbers are recorded in extra reserved area in
> >> hot node curseg journal, the journal will be persisted only for umount
> >> or fastboot checkpoint, so the numbers are not so accurate... does this
> >> satisfy your requirement?
> >>
> >
> > Yes, we are satisfied with just getting rough number of them. But, it
>
> Alright,
>
> > would be better if you suggest more accurate way. :)
>
> I think this is the cheapest way to store rough number, otherwise it needs to 
> change
> f2fs_checkpoint structure layout or add a new inner inode to persist these 
> stat
> numbers if we want more accurate one.
>
> >
> >>> compression in sysfs. These can be re-initialized to "0" by writing "0"
> >>> value in one of both.
> >>
> >> Why do we allow reset the stat numbers?
> >>
> >
> > Actually, I want to have a way to clear any stale number of them, but
> > I agree we don't need this.
> >
> >> Why not covering all code with macro CONFIG_F2FS_FS_COMPRESSION, since 
> >> these
> >> numbers are only be updated when we enable compression.
> >>
> >
> > I wanted to keep the info even in the kernel with doesn't support
> > per-file compression if those had been written once. What do you
> > think?
>
> Sure, if so it's fine to me. :)
>
> Thanks,
>
> >
> >> Thanks,
> > .
> >

Re: [f2fs-dev] [PATCH v2] f2fs: add sysfs nodes to get accumulated compression info

[Daeho Jeong]

2021년 3월 9일 (화) 오후 6:22, Chao Yu 님이 작성:
>
> On 2021/3/5 10:24, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added acc_compr_inodes to show accumulated compressed inode count and
> > acc_compr_blocks to show accumulated secured block count with
>
> I noticed that these stat numbers are recorded in extra reserved area in
> hot node curseg journal, the journal will be persisted only for umount
> or fastboot checkpoint, so the numbers are not so accurate... does this
> satisfy your requirement?
>

Yes, we are satisfied with just getting rough number of them. But, it
would be better if you suggest more accurate way. :)

> > compression in sysfs. These can be re-initialized to "0" by writing "0"
> > value in one of both.
>
> Why do we allow reset the stat numbers?
>

Actually, I want to have a way to clear any stale number of them, but
I agree we don't need this.

> Why not covering all code with macro CONFIG_F2FS_FS_COMPRESSION, since these
> numbers are only be updated when we enable compression.
>

I wanted to keep the info even in the kernel with doesn't support
per-file compression if those had been written once. What do you
think?

> Thanks,

[PATCH v2] f2fs: add sysfs nodes to get accumulated compression info

[Daeho Jeong]

From: Daeho Jeong 

Added acc_compr_inodes to show accumulated compressed inode count and
acc_compr_blocks to show accumulated secured block count with
compression in sysfs. These can be re-initialized to "0" by writing "0"
value in one of both.

Signed-off-by: Daeho Jeong 
---
v2: thanks to kernel test robot , fixed compile issue
related to kernel config.
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 13 +++
 fs/f2fs/checkpoint.c|  8 
 fs/f2fs/compress.c  |  4 +-
 fs/f2fs/data.c  |  2 +-
 fs/f2fs/f2fs.h  | 50 -
 fs/f2fs/file.c  |  8 ++--
 fs/f2fs/inode.c |  1 +
 fs/f2fs/super.c | 10 -
 fs/f2fs/sysfs.c | 45 ++
 include/linux/f2fs_fs.h |  4 +-
 10 files changed, 135 insertions(+), 10 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index cbeac1bebe2f..f4fc87503754 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -409,3 +409,16 @@ Description:   Give a way to change checkpoint merge 
daemon's io priority.
I/O priority "3". We can select the class between "rt" and "be",
and set the I/O priority within valid range of it. "," delimiter
is necessary in between I/O class and priority number.
+
+What:  /sys/fs/f2fs//acc_compr_inodes
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show accumulated compressed inode count. If you write "0" here,
+   you can initialize acc_compr_inodes and acc_compr_blocks as "0".
+
+What:  /sys/fs/f2fs//acc_compr_blocks
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show accumulated secured block count with compression.
+   If you write "0" here, you can initialize acc_compr_inodes and
+   acc_compr_blocks as "0".
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 174a0819ad96..cd944a569162 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1514,6 +1514,14 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, 
struct cp_control *cpc)
seg_i->journal->info.kbytes_written = cpu_to_le64(kbytes_written);
 
if (__remain_node_summaries(cpc->reason)) {
+   /* Record compression statistics in the hot node summary */
+   spin_lock(&sbi->acc_compr_lock);
+   seg_i->journal->info.acc_compr_blocks =
+   cpu_to_le64(sbi->acc_compr_blocks);
+   seg_i->journal->info.acc_compr_inodes =
+   cpu_to_le32(sbi->acc_compr_inodes);
+   spin_unlock(&sbi->acc_compr_lock);
+
f2fs_write_node_summaries(sbi, start_blk);
start_blk += NR_CURSEG_NODE_TYPE;
}
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 77fa342de38f..9029e95f4ae4 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1351,8 +1351,8 @@ static int f2fs_write_compressed_pages(struct 
compress_ctx *cc,
}
 
if (fio.compr_blocks)
-   f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
-   f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
+   f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false, 
true);
+   f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true, true);
 
set_inode_flag(cc->inode, FI_APPEND_WRITE);
if (cc->cluster_idx == 0)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b9721c8f116c..d3afb9b0090e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2591,7 +2591,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
ClearPageError(page);
 
if (fio->compr_blocks && fio->old_blkaddr == COMPRESS_ADDR)
-   f2fs_i_compr_blocks_update(inode, fio->compr_blocks - 1, false);
+   f2fs_i_compr_blocks_update(inode, fio->compr_blocks - 1, false, 
true);
 
/* LFS mode write path */
f2fs_outplace_write_data(&dn, fio);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e2d302ae3a46..a12edf5283cd 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1609,6 +1609,11 @@ struct f2fs_sb_info {
u64 sectors_written_start;
u64 kbytes_written;
 
+   /* For accumulated compression statistics */
+   u64 acc_compr_blocks;
+   u32 acc_compr_inodes;
+   spinlock_t acc_compr_lock;
+
/* Reference to checksum algorithm driver via cryptoapi */
struct crypto_shash *s_chksum_driver;
 
@@ -3985,6 +3990,43 @@ static inline int __i

[PATCH] f2fs: add sysfs nodes to get accumulated compression info

[Daeho Jeong]

From: Daeho Jeong 

Added acc_compr_inodes to show accumulated compressed inode count and
acc_compr_blocks to show accumulated secured block count with
compression in sysfs. These can be re-initialized to "0" by writing "0"
value in one of both.

Signed-off-by: Daeho Jeong 
---
 Documentation/ABI/testing/sysfs-fs-f2fs | 13 +++
 fs/f2fs/checkpoint.c|  8 
 fs/f2fs/compress.c  |  4 +-
 fs/f2fs/data.c  |  2 +-
 fs/f2fs/f2fs.h  | 49 -
 fs/f2fs/file.c  |  8 ++--
 fs/f2fs/inode.c |  1 +
 fs/f2fs/super.c | 10 -
 fs/f2fs/sysfs.c | 45 +++
 include/linux/f2fs_fs.h |  4 +-
 10 files changed, 134 insertions(+), 10 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index cbeac1bebe2f..f4fc87503754 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -409,3 +409,16 @@ Description:   Give a way to change checkpoint merge 
daemon's io priority.
I/O priority "3". We can select the class between "rt" and "be",
and set the I/O priority within valid range of it. "," delimiter
is necessary in between I/O class and priority number.
+
+What:  /sys/fs/f2fs//acc_compr_inodes
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show accumulated compressed inode count. If you write "0" here,
+   you can initialize acc_compr_inodes and acc_compr_blocks as "0".
+
+What:  /sys/fs/f2fs//acc_compr_blocks
+Date:  March 2021
+Contact:   "Daeho Jeong" 
+Description:   Show accumulated secured block count with compression.
+   If you write "0" here, you can initialize acc_compr_inodes and
+   acc_compr_blocks as "0".
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 174a0819ad96..cd944a569162 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1514,6 +1514,14 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, 
struct cp_control *cpc)
seg_i->journal->info.kbytes_written = cpu_to_le64(kbytes_written);
 
if (__remain_node_summaries(cpc->reason)) {
+   /* Record compression statistics in the hot node summary */
+   spin_lock(&sbi->acc_compr_lock);
+   seg_i->journal->info.acc_compr_blocks =
+   cpu_to_le64(sbi->acc_compr_blocks);
+   seg_i->journal->info.acc_compr_inodes =
+   cpu_to_le32(sbi->acc_compr_inodes);
+   spin_unlock(&sbi->acc_compr_lock);
+
f2fs_write_node_summaries(sbi, start_blk);
start_blk += NR_CURSEG_NODE_TYPE;
}
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 77fa342de38f..9029e95f4ae4 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1351,8 +1351,8 @@ static int f2fs_write_compressed_pages(struct 
compress_ctx *cc,
}
 
if (fio.compr_blocks)
-   f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
-   f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
+   f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false, 
true);
+   f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true, true);
 
set_inode_flag(cc->inode, FI_APPEND_WRITE);
if (cc->cluster_idx == 0)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b9721c8f116c..d3afb9b0090e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2591,7 +2591,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
ClearPageError(page);
 
if (fio->compr_blocks && fio->old_blkaddr == COMPRESS_ADDR)
-   f2fs_i_compr_blocks_update(inode, fio->compr_blocks - 1, false);
+   f2fs_i_compr_blocks_update(inode, fio->compr_blocks - 1, false, 
true);
 
/* LFS mode write path */
f2fs_outplace_write_data(&dn, fio);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e2d302ae3a46..4351ca77fa13 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1609,6 +1609,11 @@ struct f2fs_sb_info {
u64 sectors_written_start;
u64 kbytes_written;
 
+   /* For accumulated compression statistics */
+   u64 acc_compr_blocks;
+   u32 acc_compr_inodes;
+   spinlock_t acc_compr_lock;
+
/* Reference to checksum algorithm driver via cryptoapi */
struct crypto_shash *s_chksum_driver;
 
@@ -3675,10 +3680,46 @@ static inline struct f2fs_stat_info *F2FS_STAT(struct 
f2fs_sb_info *sbi)
if (f2fs_compressed_file(inode))   

[PATCH v5] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

From: Daeho Jeong 

As checkpoint=merge comes in, mount option setting related to checkpoint
had been mixed up and it became hard to understand. So, I separated
this option from "checkpoint=" and made another mount option
"checkpoint_merge" for this.

Signed-off-by: Daeho Jeong 
---
v2: renamed "checkpoint=merge" to "checkpoint_merge"
v3: removed "nocheckpoint_merge" option
v4: re-added "nocheckpoint_merge" option to make it possible to disable
just only "checkpoint_merge" when remount
v5: added the description about "nocheckpoint_merge" in rst and added it
in show_options
---
 Documentation/filesystems/f2fs.rst |  7 ---
 fs/f2fs/super.c| 27 +++
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index d0ead45dc706..f75ec244762f 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
-Here is another option "merge", which creates a kernel 
daemon
-and makes it to merge concurrent checkpoint requests 
as much
-as possible to eliminate redundant checkpoint issues. 
Plus,
+checkpoint_mergeWhen checkpoint is enabled, this can be used to create 
a kernel
+daemon and make it to merge concurrent checkpoint 
requests as
+much as possible to eliminate redundant checkpoint 
issues. Plus,
 we can eliminate the sluggish issue caused by slow 
checkpoint
 operation when the checkpoint is done in a process 
context in
 a cgroup having low i/o budget and cpu shares. To make 
this
@@ -257,6 +257,7 @@ checkpoint=%s[:%u[%]]Set to "disable" to turn off 
checkpointing. Set to "enabl
 to "3", to give one higher priority than other kernel 
threads.
 This is the same way to give a I/O priority to the jbd2
 journaling thread of ext4 filesystem.
+nocheckpoint_merge  Disable checkpoint merge feature.
 compress_algorithm=%s   Control compress algorithm, currently f2fs supports 
"lzo",
 "lz4", "zstd" and "lzo-rle" algorithm.
 compress_algorithm=%s:%d Control compress algorithm and its compress level, 
now, only
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56696f6cfa86..1000d21120ca 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -145,6 +145,7 @@ enum {
Opt_checkpoint_disable_cap_perc,
Opt_checkpoint_enable,
Opt_checkpoint_merge,
+   Opt_nocheckpoint_merge,
Opt_compress_algorithm,
Opt_compress_log_size,
Opt_compress_extension,
@@ -215,7 +216,8 @@ static match_table_t f2fs_tokens = {
{Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
{Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
{Opt_checkpoint_enable, "checkpoint=enable"},
-   {Opt_checkpoint_merge, "checkpoint=merge"},
+   {Opt_checkpoint_merge, "checkpoint_merge"},
+   {Opt_nocheckpoint_merge, "nocheckpoint_merge"},
{Opt_compress_algorithm, "compress_algorithm=%s"},
{Opt_compress_log_size, "compress_log_size=%u"},
{Opt_compress_extension, "compress_extension=%s"},
@@ -946,6 +948,9 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
case Opt_checkpoint_merge:
set_opt(sbi, MERGE_CHECKPOINT);
break;
+   case Opt_nocheckpoint_merge:
+   clear_opt(sbi, MERGE_CHECKPOINT);
+   break;
 #ifdef CONFIG_F2FS_FS_COMPRESSION
case Opt_compress_algorithm:
if (!f2fs_sb_has_compression(sbi)) {
@@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
return -EINVAL;
}
 
-   if (test_opt(sbi, DISABLE_CHECKPOINT) &&
-   test_opt(sbi, MERGE_CHECKPOINT)) {
-   f2fs_err(sbi, "checkpoint=merge cannot be used with 
checkpoint=disable\n");
-   return -EINVAL;
-   }
-
/* Not pass down write hints if the number of active logs is lesser
 * than

[PATCH v4] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

From: Daeho Jeong 

As checkpoint=merge comes in, mount option setting related to checkpoint
had been mixed up and it became hard to understand. So, I separated
this option from "checkpoint=" and made another mount option
"checkpoint_merge" for this.

Signed-off-by: Daeho Jeong 
---
v2: renamed "checkpoint=merge" to "checkpoint_merge"
v3: removed "nocheckpoint_merge" option
v4: re-added "nocheckpoint_merge" option to make it possible to disable
just only "checkpoint_merge" when remount
---
 Documentation/filesystems/f2fs.rst |  6 +++---
 fs/f2fs/super.c| 25 +
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index d0ead45dc706..475994ed8b15 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
-Here is another option "merge", which creates a kernel 
daemon
-and makes it to merge concurrent checkpoint requests 
as much
-as possible to eliminate redundant checkpoint issues. 
Plus,
+checkpoint_mergeWhen checkpoint is enabled, this can be used to create 
a kernel
+daemon and make it to merge concurrent checkpoint 
requests as
+much as possible to eliminate redundant checkpoint 
issues. Plus,
 we can eliminate the sluggish issue caused by slow 
checkpoint
 operation when the checkpoint is done in a process 
context in
 a cgroup having low i/o budget and cpu shares. To make 
this
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56696f6cfa86..f1791b9c1eac 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -145,6 +145,7 @@ enum {
Opt_checkpoint_disable_cap_perc,
Opt_checkpoint_enable,
Opt_checkpoint_merge,
+   Opt_nocheckpoint_merge,
Opt_compress_algorithm,
Opt_compress_log_size,
Opt_compress_extension,
@@ -215,7 +216,8 @@ static match_table_t f2fs_tokens = {
{Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
{Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
{Opt_checkpoint_enable, "checkpoint=enable"},
-   {Opt_checkpoint_merge, "checkpoint=merge"},
+   {Opt_checkpoint_merge, "checkpoint_merge"},
+   {Opt_nocheckpoint_merge, "nocheckpoint_merge"},
{Opt_compress_algorithm, "compress_algorithm=%s"},
{Opt_compress_log_size, "compress_log_size=%u"},
{Opt_compress_extension, "compress_extension=%s"},
@@ -946,6 +948,9 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
case Opt_checkpoint_merge:
set_opt(sbi, MERGE_CHECKPOINT);
break;
+   case Opt_nocheckpoint_merge:
+   clear_opt(sbi, MERGE_CHECKPOINT);
+   break;
 #ifdef CONFIG_F2FS_FS_COMPRESSION
case Opt_compress_algorithm:
if (!f2fs_sb_has_compression(sbi)) {
@@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
return -EINVAL;
}
 
-   if (test_opt(sbi, DISABLE_CHECKPOINT) &&
-   test_opt(sbi, MERGE_CHECKPOINT)) {
-   f2fs_err(sbi, "checkpoint=merge cannot be used with 
checkpoint=disable\n");
-   return -EINVAL;
-   }
-
/* Not pass down write hints if the number of active logs is lesser
 * than NR_CURSEG_PERSIST_TYPE.
 */
@@ -1782,7 +1781,7 @@ static int f2fs_show_options(struct seq_file *seq, struct 
dentry *root)
seq_printf(seq, ",checkpoint=disable:%u",
F2FS_OPTION(sbi).unusable_cap);
if (test_opt(sbi, MERGE_CHECKPOINT))
-   seq_puts(seq, ",checkpoint=merge");
+   seq_puts(seq, ",checkpoint_merge");
if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
seq_printf(seq, ",fsync_mode=%s", "posix");
else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
@@ -2066,9 +2065,8 @@ static int f2fs_remount(struct super_block *sb, int 
*flags, char *data)
}
}
 
-   if (!test_opt(sbi, MERGE_CHECKP

Re: [f2fs-dev] [PATCH v3] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

Thanks for the explanation.

I am going to remove the line clearing "MERGE_CHECKPOINT".
But, when we go with the below remount command, I think the
"nocheckpoint_merge" option will work well to disable only just
"checkpoint_merge" from the previous option.
"mount -o remount,nocheckpoint_merge  /dir"

It would be more convenient to users. What do you think?

2021년 2월 2일 (화) 오후 6:55, Chao Yu 님이 작성:
>
> On 2021/2/2 17:44, Daeho Jeong wrote:
> > When we remount it without the "checkpoint_merge" option, shouldn't we
> > need to clear "MERGE_CHECKPOINT" again?
> > This is actually what I intended, but I was wrong. Actually, I found this.
> >
> > When we remount the filesystem, the previous mount option is passed
> > through the "data" argument in the below.
> > f2fs_remount(struct super_block *sb, int *flags, char *data)
> >
> > If we don't provide the "nocheckpoint_merge" option, how can we turn
> > off the "checkpoint_merge" option which is turned on in the previous
> > mount?
>
> We can use "mount -o remount /dev/xxx /mnt" to disable checkpoint_merge,
> since that command won't pass old mount options to remount?
>
> Quoted from man mount:
>
>mount -o remount,rw /dev/foo /dir
>
>After  this  call  all  old  mount options are replaced and 
> arbitrary stuff from fstab (or mtab) is ignored, except the loop= option 
> which is internally generated and maintained by the
>mount command.
>
>mount -o remount,rw  /dir
>
>After this call mount reads fstab and merges these options 
> with the options from the command line (-o). If no mountpoint found in fstab 
> than remount with unspecified source is allowed.
>
> Thanks,
>
> >
> > 2021년 2월 2일 (화) 오후 6:28, Chao Yu 님이 작성:
> >>
> >> On 2021/2/2 17:23, Daeho Jeong wrote:
> >>> From: Daeho Jeong 
> >>>
> >>> As checkpoint=merge comes in, mount option setting related to checkpoint
> >>> had been mixed up and it became hard to understand. So, I separated
> >>> this option from "checkpoint=" and made another mount option
> >>> "checkpoint_merge" for this.
> >>>
> >>> Signed-off-by: Daeho Jeong 
> >>> ---
> >>> v2: renamed "checkpoint=merge" to "checkpoint_merge"
> >>> v3: removed "nocheckpoint_merge" option
> >>> ---
> >>>Documentation/filesystems/f2fs.rst |  6 +++---
> >>>fs/f2fs/super.c| 21 +
> >>>2 files changed, 12 insertions(+), 15 deletions(-)
> >>>
> >>> diff --git a/Documentation/filesystems/f2fs.rst 
> >>> b/Documentation/filesystems/f2fs.rst
> >>> index d0ead45dc706..475994ed8b15 100644
> >>> --- a/Documentation/filesystems/f2fs.rst
> >>> +++ b/Documentation/filesystems/f2fs.rst
> >>> @@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]  Set to "disable" to turn 
> >>> off checkpointing. Set to "enabl
> >>> hide up to all remaining free space. The actual 
> >>> space that
> >>> would be unusable can be viewed at 
> >>> /sys/fs/f2fs//unusable
> >>> This space is reclaimed once checkpoint=enable.
> >>> -  Here is another option "merge", which creates a 
> >>> kernel daemon
> >>> -  and makes it to merge concurrent checkpoint 
> >>> requests as much
> >>> -  as possible to eliminate redundant checkpoint 
> >>> issues. Plus,
> >>> +checkpoint_merge  When checkpoint is enabled, this can be used to 
> >>> create a kernel
> >>> +  daemon and make it to merge concurrent checkpoint 
> >>> requests as
> >>> +  much as possible to eliminate redundant checkpoint 
> >>> issues. Plus,
> >>> we can eliminate the sluggish issue caused by 
> >>> slow checkpoint
> >>> operation when the checkpoint is done in a 
> >>> process context in
> >>> a cgroup having low i/o budget and cpu shares. To 
> >>> make this
> >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> >>> index 56696f6cfa86

Re: [f2fs-dev] [PATCH v3] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

When we remount it without the "checkpoint_merge" option, shouldn't we
need to clear "MERGE_CHECKPOINT" again?
This is actually what I intended, but I was wrong. Actually, I found this.

When we remount the filesystem, the previous mount option is passed
through the "data" argument in the below.
f2fs_remount(struct super_block *sb, int *flags, char *data)

If we don't provide the "nocheckpoint_merge" option, how can we turn
off the "checkpoint_merge" option which is turned on in the previous
mount?

2021년 2월 2일 (화) 오후 6:28, Chao Yu 님이 작성:
>
> On 2021/2/2 17:23, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > As checkpoint=merge comes in, mount option setting related to checkpoint
> > had been mixed up and it became hard to understand. So, I separated
> > this option from "checkpoint=" and made another mount option
> > "checkpoint_merge" for this.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> > v2: renamed "checkpoint=merge" to "checkpoint_merge"
> > v3: removed "nocheckpoint_merge" option
> > ---
> >   Documentation/filesystems/f2fs.rst |  6 +++---
> >   fs/f2fs/super.c| 21 +
> >   2 files changed, 12 insertions(+), 15 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index d0ead45dc706..475994ed8b15 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]  Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > -  Here is another option "merge", which creates a 
> > kernel daemon
> > -  and makes it to merge concurrent checkpoint requests 
> > as much
> > -  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +checkpoint_merge  When checkpoint is enabled, this can be used to 
> > create a kernel
> > +  daemon and make it to merge concurrent checkpoint 
> > requests as
> > +  much as possible to eliminate redundant checkpoint 
> > issues. Plus,
> >we can eliminate the sluggish issue caused by slow 
> > checkpoint
> >operation when the checkpoint is done in a process 
> > context in
> >a cgroup having low i/o budget and cpu shares. To 
> > make this
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 56696f6cfa86..b60dcef7f9d0 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -215,7 +215,7 @@ static match_table_t f2fs_tokens = {
> >   {Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
> >   {Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
> >   {Opt_checkpoint_enable, "checkpoint=enable"},
> > - {Opt_checkpoint_merge, "checkpoint=merge"},
> > + {Opt_checkpoint_merge, "checkpoint_merge"},
> >   {Opt_compress_algorithm, "compress_algorithm=%s"},
> >   {Opt_compress_log_size, "compress_log_size=%u"},
> >   {Opt_compress_extension, "compress_extension=%s"},
> > @@ -1142,12 +1142,6 @@ static int parse_options(struct super_block *sb, 
> > char *options, bool is_remount)
> >   return -EINVAL;
> >   }
> >
> > - if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > - test_opt(sbi, MERGE_CHECKPOINT)) {
> > - f2fs_err(sbi, "checkpoint=merge cannot be used with 
> > checkpoint=disable\n");
> > - return -EINVAL;
> > - }
> > -
> >   /* Not pass down write hints if the number of active logs is lesser
> >* than NR_CURSEG_PERSIST_TYPE.
> >*/
> > @@ -1782,7 +1776,7 @@ static int f2fs_show_options(struct seq_file *seq, 
> > struct dentry *root)
> >   seq_printf(seq, ",checkpoint=disable:%u",
> >   F2FS_OPTION(sbi).unusable_cap);
> >   if (test_opt(sbi, MERGE_CHECKPOINT))
> > - seq_puts(seq, ",checkpoint=merge");
&

[PATCH v3] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

From: Daeho Jeong 

As checkpoint=merge comes in, mount option setting related to checkpoint
had been mixed up and it became hard to understand. So, I separated
this option from "checkpoint=" and made another mount option
"checkpoint_merge" for this.

Signed-off-by: Daeho Jeong 
---
v2: renamed "checkpoint=merge" to "checkpoint_merge"
v3: removed "nocheckpoint_merge" option
---
 Documentation/filesystems/f2fs.rst |  6 +++---
 fs/f2fs/super.c| 21 +
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index d0ead45dc706..475994ed8b15 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
-Here is another option "merge", which creates a kernel 
daemon
-and makes it to merge concurrent checkpoint requests 
as much
-as possible to eliminate redundant checkpoint issues. 
Plus,
+checkpoint_mergeWhen checkpoint is enabled, this can be used to create 
a kernel
+daemon and make it to merge concurrent checkpoint 
requests as
+much as possible to eliminate redundant checkpoint 
issues. Plus,
 we can eliminate the sluggish issue caused by slow 
checkpoint
 operation when the checkpoint is done in a process 
context in
 a cgroup having low i/o budget and cpu shares. To make 
this
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56696f6cfa86..b60dcef7f9d0 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -215,7 +215,7 @@ static match_table_t f2fs_tokens = {
{Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
{Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
{Opt_checkpoint_enable, "checkpoint=enable"},
-   {Opt_checkpoint_merge, "checkpoint=merge"},
+   {Opt_checkpoint_merge, "checkpoint_merge"},
{Opt_compress_algorithm, "compress_algorithm=%s"},
{Opt_compress_log_size, "compress_log_size=%u"},
{Opt_compress_extension, "compress_extension=%s"},
@@ -1142,12 +1142,6 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
return -EINVAL;
}
 
-   if (test_opt(sbi, DISABLE_CHECKPOINT) &&
-   test_opt(sbi, MERGE_CHECKPOINT)) {
-   f2fs_err(sbi, "checkpoint=merge cannot be used with 
checkpoint=disable\n");
-   return -EINVAL;
-   }
-
/* Not pass down write hints if the number of active logs is lesser
 * than NR_CURSEG_PERSIST_TYPE.
 */
@@ -1782,7 +1776,7 @@ static int f2fs_show_options(struct seq_file *seq, struct 
dentry *root)
seq_printf(seq, ",checkpoint=disable:%u",
F2FS_OPTION(sbi).unusable_cap);
if (test_opt(sbi, MERGE_CHECKPOINT))
-   seq_puts(seq, ",checkpoint=merge");
+   seq_puts(seq, ",checkpoint_merge");
if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
seq_printf(seq, ",fsync_mode=%s", "posix");
else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
@@ -1827,6 +1821,7 @@ static void default_options(struct f2fs_sb_info *sbi)
sbi->sb->s_flags |= SB_LAZYTIME;
set_opt(sbi, FLUSH_MERGE);
set_opt(sbi, DISCARD);
+   clear_opt(sbi, MERGE_CHECKPOINT);
if (f2fs_sb_has_blkzoned(sbi))
F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS;
else
@@ -2066,9 +2061,8 @@ static int f2fs_remount(struct super_block *sb, int 
*flags, char *data)
}
}
 
-   if (!test_opt(sbi, MERGE_CHECKPOINT)) {
-   f2fs_stop_ckpt_thread(sbi);
-   } else {
+   if (!test_opt(sbi, DISABLE_CHECKPOINT) &&
+   test_opt(sbi, MERGE_CHECKPOINT)) {
err = f2fs_start_ckpt_thread(sbi);
if (err) {
f2fs_err(sbi,
@@ -2076,6 +2070,8 @@ static int f2fs_remount(struct super_block *sb, int 
*flags, char *data)
err);
goto restore_gc;
}
+   } else {
+   f2fs_stop_ckpt_thread(sbi);
}
 
/*
@@ -3831,7 +3827,8 @@ static int f2fs_fill_super(struct s

Re: [f2fs-dev] [PATCH v2] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

If I understand it correctly, the only thing I have to do now is
remove "nocheckpoint_merge" now.
Am I correct? :)

2021년 2월 2일 (화) 오후 5:30, Chao Yu 님이 작성:
>
> On 2021/2/2 16:02, Daeho Jeong wrote:
> > I chose the same step with "flush_merge", because it doesn't have
> > "noflush_merge".
>
> Oh, "noxxx" option was added only when we set the option by default in
> default_options(), when user want to disable the default option, it
> needs to use "noxxx" option, and then we will show this "noxxx" option
> string to user via show_options() to indicate that "noxxx" option is
> working now.
>
> Anyway I think we should fix to show "noflush_merge" option because we
> have set flush_merge by default.
>
> > Do you think we need that for both, "noflush_merge" and 
> > "nocheckpoint_merge"?
>
> For "nocheckpoint_merge", we can introduce this option only when we want
> to set "checkpoint_merge" by default.
>
> Here is the example from noinline_data:
>
> Commit 75342797988 ("f2fs: enable inline data by default")
>
> Thanks,
>
> >
> > I thought we needed to give some time to make this be turned on by
> > default. It might be a little radical. :)
> >
> > What do you think?
> >
> > 2021년 2월 2일 (화) 오후 4:40, Chao Yu 님이 작성:
> >>
> >> On 2021/2/2 13:18, Daeho Jeong wrote:
> >>> From: Daeho Jeong 
> >>>
> >>> As checkpoint=merge comes in, mount option setting related to checkpoint
> >>> had been mixed up and it became hard to understand. So, I separated
> >>> this option from "checkpoint=" and made another mount option
> >>> "checkpoint_merge" for this.
> >>>
> >>> Signed-off-by: Daeho Jeong 
> >>> ---
> >>> v2: renamed "checkpoint=merge" to "checkpoint_merge"
> >>> ---
> >>>Documentation/filesystems/f2fs.rst |  6 +++---
> >>>fs/f2fs/super.c| 26 ++
> >>>2 files changed, 17 insertions(+), 15 deletions(-)
> >>>
> >>> diff --git a/Documentation/filesystems/f2fs.rst 
> >>> b/Documentation/filesystems/f2fs.rst
> >>> index d0ead45dc706..475994ed8b15 100644
> >>> --- a/Documentation/filesystems/f2fs.rst
> >>> +++ b/Documentation/filesystems/f2fs.rst
> >>> @@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]  Set to "disable" to turn 
> >>> off checkpointing. Set to "enabl
> >>> hide up to all remaining free space. The actual 
> >>> space that
> >>> would be unusable can be viewed at 
> >>> /sys/fs/f2fs//unusable
> >>> This space is reclaimed once checkpoint=enable.
> >>> -  Here is another option "merge", which creates a 
> >>> kernel daemon
> >>> -  and makes it to merge concurrent checkpoint 
> >>> requests as much
> >>> -  as possible to eliminate redundant checkpoint 
> >>> issues. Plus,
> >>> +checkpoint_merge  When checkpoint is enabled, this can be used to 
> >>> create a kernel
> >>> +  daemon and make it to merge concurrent checkpoint 
> >>> requests as
> >>> +  much as possible to eliminate redundant checkpoint 
> >>> issues. Plus,
> >>> we can eliminate the sluggish issue caused by 
> >>> slow checkpoint
> >>> operation when the checkpoint is done in a 
> >>> process context in
> >>> a cgroup having low i/o budget and cpu shares. To 
> >>> make this
> >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> >>> index 56696f6cfa86..d8603e6c4916 100644
> >>> --- a/fs/f2fs/super.c
> >>> +++ b/fs/f2fs/super.c
> >>> @@ -145,6 +145,7 @@ enum {
> >>>Opt_checkpoint_disable_cap_perc,
> >>>Opt_checkpoint_enable,
> >>>Opt_checkpoint_merge,
> >>> + Opt_nocheckpoint_merge,
> >>>Opt_compress_algorithm,
> >>>Opt_compress_log_size,
> >>>Opt_compress_extension,
> >>> @@ -215,7 +216,8 @@ static match_table_t f2fs_tokens = {
> >>>{Opt_checkpoint_disabl

Re: [f2fs-dev] [PATCH v2] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

I chose the same step with "flush_merge", because it doesn't have
"noflush_merge".
Do you think we need that for both, "noflush_merge" and "nocheckpoint_merge"?

I thought we needed to give some time to make this be turned on by
default. It might be a little radical. :)

What do you think?

2021년 2월 2일 (화) 오후 4:40, Chao Yu 님이 작성:
>
> On 2021/2/2 13:18, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > As checkpoint=merge comes in, mount option setting related to checkpoint
> > had been mixed up and it became hard to understand. So, I separated
> > this option from "checkpoint=" and made another mount option
> > "checkpoint_merge" for this.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> > v2: renamed "checkpoint=merge" to "checkpoint_merge"
> > ---
> >   Documentation/filesystems/f2fs.rst |  6 +++---
> >   fs/f2fs/super.c| 26 ++
> >   2 files changed, 17 insertions(+), 15 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index d0ead45dc706..475994ed8b15 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]  Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > -  Here is another option "merge", which creates a 
> > kernel daemon
> > -  and makes it to merge concurrent checkpoint requests 
> > as much
> > -  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +checkpoint_merge  When checkpoint is enabled, this can be used to 
> > create a kernel
> > +  daemon and make it to merge concurrent checkpoint 
> > requests as
> > +  much as possible to eliminate redundant checkpoint 
> > issues. Plus,
> >we can eliminate the sluggish issue caused by slow 
> > checkpoint
> >operation when the checkpoint is done in a process 
> > context in
> >a cgroup having low i/o budget and cpu shares. To 
> > make this
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 56696f6cfa86..d8603e6c4916 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -145,6 +145,7 @@ enum {
> >   Opt_checkpoint_disable_cap_perc,
> >   Opt_checkpoint_enable,
> >   Opt_checkpoint_merge,
> > + Opt_nocheckpoint_merge,
> >   Opt_compress_algorithm,
> >   Opt_compress_log_size,
> >   Opt_compress_extension,
> > @@ -215,7 +216,8 @@ static match_table_t f2fs_tokens = {
> >   {Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
> >   {Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
> >   {Opt_checkpoint_enable, "checkpoint=enable"},
> > - {Opt_checkpoint_merge, "checkpoint=merge"},
> > + {Opt_checkpoint_merge, "checkpoint_merge"},
> > + {Opt_nocheckpoint_merge, "nocheckpoint_merge"},
> >   {Opt_compress_algorithm, "compress_algorithm=%s"},
> >   {Opt_compress_log_size, "compress_log_size=%u"},
> >   {Opt_compress_extension, "compress_extension=%s"},
> > @@ -946,6 +948,9 @@ static int parse_options(struct super_block *sb, char 
> > *options, bool is_remount)
> >   case Opt_checkpoint_merge:
> >   set_opt(sbi, MERGE_CHECKPOINT);
> >   break;
> > + case Opt_nocheckpoint_merge:
> > + clear_opt(sbi, MERGE_CHECKPOINT);
> > + break;
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> >   case Opt_compress_algorithm:
> >   if (!f2fs_sb_has_compression(sbi)) {
> > @@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, 
> > char *options, bool is_remount)
> >   return -EINVAL;
> >   }
> >
> > - if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > - test_opt(sbi, MERGE_CHECKPOINT)) {
> > - f2fs_err(sbi, &quo

[PATCH v2] f2fs: rename checkpoint=merge mount option to checkpoint_merge

[Daeho Jeong]

From: Daeho Jeong 

As checkpoint=merge comes in, mount option setting related to checkpoint
had been mixed up and it became hard to understand. So, I separated
this option from "checkpoint=" and made another mount option
"checkpoint_merge" for this.

Signed-off-by: Daeho Jeong 
---
v2: renamed "checkpoint=merge" to "checkpoint_merge"
---
 Documentation/filesystems/f2fs.rst |  6 +++---
 fs/f2fs/super.c| 26 ++
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index d0ead45dc706..475994ed8b15 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]]Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
-Here is another option "merge", which creates a kernel 
daemon
-and makes it to merge concurrent checkpoint requests 
as much
-as possible to eliminate redundant checkpoint issues. 
Plus,
+checkpoint_mergeWhen checkpoint is enabled, this can be used to create 
a kernel
+daemon and make it to merge concurrent checkpoint 
requests as
+much as possible to eliminate redundant checkpoint 
issues. Plus,
 we can eliminate the sluggish issue caused by slow 
checkpoint
 operation when the checkpoint is done in a process 
context in
 a cgroup having low i/o budget and cpu shares. To make 
this
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56696f6cfa86..d8603e6c4916 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -145,6 +145,7 @@ enum {
Opt_checkpoint_disable_cap_perc,
Opt_checkpoint_enable,
Opt_checkpoint_merge,
+   Opt_nocheckpoint_merge,
Opt_compress_algorithm,
Opt_compress_log_size,
Opt_compress_extension,
@@ -215,7 +216,8 @@ static match_table_t f2fs_tokens = {
{Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
{Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
{Opt_checkpoint_enable, "checkpoint=enable"},
-   {Opt_checkpoint_merge, "checkpoint=merge"},
+   {Opt_checkpoint_merge, "checkpoint_merge"},
+   {Opt_nocheckpoint_merge, "nocheckpoint_merge"},
{Opt_compress_algorithm, "compress_algorithm=%s"},
{Opt_compress_log_size, "compress_log_size=%u"},
{Opt_compress_extension, "compress_extension=%s"},
@@ -946,6 +948,9 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
case Opt_checkpoint_merge:
set_opt(sbi, MERGE_CHECKPOINT);
break;
+   case Opt_nocheckpoint_merge:
+   clear_opt(sbi, MERGE_CHECKPOINT);
+   break;
 #ifdef CONFIG_F2FS_FS_COMPRESSION
case Opt_compress_algorithm:
if (!f2fs_sb_has_compression(sbi)) {
@@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
return -EINVAL;
}
 
-   if (test_opt(sbi, DISABLE_CHECKPOINT) &&
-   test_opt(sbi, MERGE_CHECKPOINT)) {
-   f2fs_err(sbi, "checkpoint=merge cannot be used with 
checkpoint=disable\n");
-   return -EINVAL;
-   }
-
/* Not pass down write hints if the number of active logs is lesser
 * than NR_CURSEG_PERSIST_TYPE.
 */
@@ -1782,7 +1781,7 @@ static int f2fs_show_options(struct seq_file *seq, struct 
dentry *root)
seq_printf(seq, ",checkpoint=disable:%u",
F2FS_OPTION(sbi).unusable_cap);
if (test_opt(sbi, MERGE_CHECKPOINT))
-   seq_puts(seq, ",checkpoint=merge");
+   seq_puts(seq, ",checkpoint_merge");
if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
seq_printf(seq, ",fsync_mode=%s", "posix");
else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
@@ -1827,6 +1826,7 @@ static void default_options(struct f2fs_sb_info *sbi)
sbi->sb->s_flags |= SB_LAZYTIME;
set_opt(sbi, FLUSH_MERGE);
set_opt(sbi, DISCARD);
+   clear_opt(sbi, MERGE_CHECKPOINT);
if (f2fs_sb_has_blkzoned(sbi))
F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS;
else
@@ -2066,9 +2066,8 @@ stat

Re: [f2fs-dev] [PATCH] f2fs: fix checkpoint mount option wrong combination

[Daeho Jeong]

For less confusion, I am going to separate the "merge" option from
"checkpoint=".
I am adding another "ckpt_merge" option. :)

2021년 2월 2일 (화) 오전 8:33, Daeho Jeong 님이 작성:
>
> The rightmost one is the final option. And checkpoint=merge means
> checkpoint is enabled with a checkpoint thread.
>
> mount checkpoint=disable,checkpoint=merge => checkpoint=merge
> remount checkpoint=enable,checkpoint=merge => checkpoint=merge
> remount checkpoint=merge,checkpoint=disable => checkpoint=disable
> remount checkpoint=merge,checkpoint=enable => checkpoint=enable
>
> Like
>
> mount fsync_mode=posix, fsync_mode=strict, fsync_mode=nobarrier =>
> fsync_mode=nobarrier
>
> 2021년 2월 2일 (화) 오전 5:11, Jaegeuk Kim 님이 작성:
> >
> > On 02/01, Daeho Jeong wrote:
> > > Actually, I think we need to select one among them, disable, enable
> > > and merge. I realized my previous understanding about that was wrong.
> > > In that case of "checkpoint=merge,checkpoint=enable", the last option
> > > will override the ones before that.
> > > This is how the other mount options like fsync_mode, whint_mode and etc.
> > > So, the answer will be "checkpoint=enable". What do you think?
> >
> > We need to clarify a bit more. :)
> >
> > mount checkpoint=disable,checkpoint=merge
> > remount checkpoint=enable,checkpoint=merge
> >
> > Then, is it going to enable checkpoint with a thread?
> >
> > >
> > >
> > >
> > > 2021년 2월 1일 (월) 오후 9:40, Chao Yu 님이 작성:
> > > >
> > > > On 2021/2/1 8:06, Daeho Jeong wrote:
> > > > > From: Daeho Jeong 
> > > > >
> > > > > As checkpoint=merge comes in, mount option setting related to
> > > > > checkpoint had been mixed up. Fixed it.
> > > > >
> > > > > Signed-off-by: Daeho Jeong 
> > > > > ---
> > > > >   fs/f2fs/super.c | 11 +--
> > > > >   1 file changed, 5 insertions(+), 6 deletions(-)
> > > > >
> > > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > > > > index 56696f6cfa86..8231c888c772 100644
> > > > > --- a/fs/f2fs/super.c
> > > > > +++ b/fs/f2fs/super.c
> > > > > @@ -930,20 +930,25 @@ static int parse_options(struct super_block 
> > > > > *sb, char *options, bool is_remount)
> > > > >   return -EINVAL;
> > > > >   F2FS_OPTION(sbi).unusable_cap_perc = arg;
> > > > >   set_opt(sbi, DISABLE_CHECKPOINT);
> > > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > > >   break;
> > > > >   case Opt_checkpoint_disable_cap:
> > > > >   if (args->from && match_int(args, &arg))
> > > > >   return -EINVAL;
> > > > >   F2FS_OPTION(sbi).unusable_cap = arg;
> > > > >   set_opt(sbi, DISABLE_CHECKPOINT);
> > > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > > >   break;
> > > > >   case Opt_checkpoint_disable:
> > > > >   set_opt(sbi, DISABLE_CHECKPOINT);
> > > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > > >   break;
> > > > >   case Opt_checkpoint_enable:
> > > > >   clear_opt(sbi, DISABLE_CHECKPOINT);
> > > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > >
> > > > What if: -o checkpoint=merge,checkpoint=enable
> > > >
> > > > Can you please explain the rule of merge/disable/enable combination and 
> > > > their
> > > > result? e.g.
> > > > checkpoint=merge,checkpoint=enable
> > > > checkpoint=enable,checkpoint=merge
> > > > checkpoint=merge,checkpoint=disable
> > > > checkpoint=disable,checkpoint=merge
> > > >
> > > > If the rule/result is clear, it should be documented.
> > > >
> > > > Thanks,
> > > >
> > > >
> > > > >   break;
> > > > >   case Opt_checkpoint_merge:
> > > > > + clear_opt(sbi, DISABLE_CHECKPOINT);
> > > > >   set_opt(sbi, MERGE_CHECKPOINT);
> > > > >   break;
> > > > >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> > > > > @@ -1142,12 +1147,6 @@ static int parse_options(struct super_block 
> > > > > *sb, char *options, bool is_remount)
> > > > >   return -EINVAL;
> > > > >   }
> > > > >
> > > > > - if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > > > > - test_opt(sbi, MERGE_CHECKPOINT)) {
> > > > > - f2fs_err(sbi, "checkpoint=merge cannot be used with 
> > > > > checkpoint=disable\n");
> > > > > - return -EINVAL;
> > > > > - }
> > > > > -
> > > > >   /* Not pass down write hints if the number of active logs is 
> > > > > lesser
> > > > >* than NR_CURSEG_PERSIST_TYPE.
> > > > >*/
> > > > >
> > >
> > >
> > > ___
> > > Linux-f2fs-devel mailing list
> > > linux-f2fs-de...@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [PATCH] f2fs: fix checkpoint mount option wrong combination

[Daeho Jeong]

The rightmost one is the final option. And checkpoint=merge means
checkpoint is enabled with a checkpoint thread.

mount checkpoint=disable,checkpoint=merge => checkpoint=merge
remount checkpoint=enable,checkpoint=merge => checkpoint=merge
remount checkpoint=merge,checkpoint=disable => checkpoint=disable
remount checkpoint=merge,checkpoint=enable => checkpoint=enable

Like

mount fsync_mode=posix, fsync_mode=strict, fsync_mode=nobarrier =>
fsync_mode=nobarrier

2021년 2월 2일 (화) 오전 5:11, Jaegeuk Kim 님이 작성:
>
> On 02/01, Daeho Jeong wrote:
> > Actually, I think we need to select one among them, disable, enable
> > and merge. I realized my previous understanding about that was wrong.
> > In that case of "checkpoint=merge,checkpoint=enable", the last option
> > will override the ones before that.
> > This is how the other mount options like fsync_mode, whint_mode and etc.
> > So, the answer will be "checkpoint=enable". What do you think?
>
> We need to clarify a bit more. :)
>
> mount checkpoint=disable,checkpoint=merge
> remount checkpoint=enable,checkpoint=merge
>
> Then, is it going to enable checkpoint with a thread?
>
> >
> >
> >
> > 2021년 2월 1일 (월) 오후 9:40, Chao Yu 님이 작성:
> > >
> > > On 2021/2/1 8:06, Daeho Jeong wrote:
> > > > From: Daeho Jeong 
> > > >
> > > > As checkpoint=merge comes in, mount option setting related to
> > > > checkpoint had been mixed up. Fixed it.
> > > >
> > > > Signed-off-by: Daeho Jeong 
> > > > ---
> > > >   fs/f2fs/super.c | 11 +--
> > > >   1 file changed, 5 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > > > index 56696f6cfa86..8231c888c772 100644
> > > > --- a/fs/f2fs/super.c
> > > > +++ b/fs/f2fs/super.c
> > > > @@ -930,20 +930,25 @@ static int parse_options(struct super_block *sb, 
> > > > char *options, bool is_remount)
> > > >   return -EINVAL;
> > > >   F2FS_OPTION(sbi).unusable_cap_perc = arg;
> > > >   set_opt(sbi, DISABLE_CHECKPOINT);
> > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > >   break;
> > > >   case Opt_checkpoint_disable_cap:
> > > >   if (args->from && match_int(args, &arg))
> > > >   return -EINVAL;
> > > >   F2FS_OPTION(sbi).unusable_cap = arg;
> > > >   set_opt(sbi, DISABLE_CHECKPOINT);
> > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > >   break;
> > > >   case Opt_checkpoint_disable:
> > > >   set_opt(sbi, DISABLE_CHECKPOINT);
> > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > > >   break;
> > > >   case Opt_checkpoint_enable:
> > > >   clear_opt(sbi, DISABLE_CHECKPOINT);
> > > > + clear_opt(sbi, MERGE_CHECKPOINT);
> > >
> > > What if: -o checkpoint=merge,checkpoint=enable
> > >
> > > Can you please explain the rule of merge/disable/enable combination and 
> > > their
> > > result? e.g.
> > > checkpoint=merge,checkpoint=enable
> > > checkpoint=enable,checkpoint=merge
> > > checkpoint=merge,checkpoint=disable
> > > checkpoint=disable,checkpoint=merge
> > >
> > > If the rule/result is clear, it should be documented.
> > >
> > > Thanks,
> > >
> > >
> > > >   break;
> > > >   case Opt_checkpoint_merge:
> > > > + clear_opt(sbi, DISABLE_CHECKPOINT);
> > > >   set_opt(sbi, MERGE_CHECKPOINT);
> > > >   break;
> > > >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> > > > @@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, 
> > > > char *options, bool is_remount)
> > > >   return -EINVAL;
> > > >   }
> > > >
> > > > - if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > > > - test_opt(sbi, MERGE_CHECKPOINT)) {
> > > > - f2fs_err(sbi, "checkpoint=merge cannot be used with 
> > > > checkpoint=disable\n");
> > > > - return -EINVAL;
> > > > - }
> > > > -
> > > >   /* Not pass down write hints if the number of active logs is 
> > > > lesser
> > > >* than NR_CURSEG_PERSIST_TYPE.
> > > >*/
> > > >
> >
> >
> > ___
> > Linux-f2fs-devel mailing list
> > linux-f2fs-de...@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [PATCH] f2fs: fix checkpoint mount option wrong combination

[Daeho Jeong]

Actually, I think we need to select one among them, disable, enable
and merge. I realized my previous understanding about that was wrong.
In that case of "checkpoint=merge,checkpoint=enable", the last option
will override the ones before that.
This is how the other mount options like fsync_mode, whint_mode and etc.
So, the answer will be "checkpoint=enable". What do you think?



2021년 2월 1일 (월) 오후 9:40, Chao Yu 님이 작성:
>
> On 2021/2/1 8:06, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > As checkpoint=merge comes in, mount option setting related to
> > checkpoint had been mixed up. Fixed it.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >   fs/f2fs/super.c | 11 +--
> >   1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 56696f6cfa86..8231c888c772 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -930,20 +930,25 @@ static int parse_options(struct super_block *sb, char 
> > *options, bool is_remount)
> >   return -EINVAL;
> >   F2FS_OPTION(sbi).unusable_cap_perc = arg;
> >   set_opt(sbi, DISABLE_CHECKPOINT);
> > + clear_opt(sbi, MERGE_CHECKPOINT);
> >   break;
> >   case Opt_checkpoint_disable_cap:
> >   if (args->from && match_int(args, &arg))
> >   return -EINVAL;
> >   F2FS_OPTION(sbi).unusable_cap = arg;
> >   set_opt(sbi, DISABLE_CHECKPOINT);
> > + clear_opt(sbi, MERGE_CHECKPOINT);
> >   break;
> >   case Opt_checkpoint_disable:
> >   set_opt(sbi, DISABLE_CHECKPOINT);
> > + clear_opt(sbi, MERGE_CHECKPOINT);
> >   break;
> >   case Opt_checkpoint_enable:
> >   clear_opt(sbi, DISABLE_CHECKPOINT);
> > + clear_opt(sbi, MERGE_CHECKPOINT);
>
> What if: -o checkpoint=merge,checkpoint=enable
>
> Can you please explain the rule of merge/disable/enable combination and their
> result? e.g.
> checkpoint=merge,checkpoint=enable
> checkpoint=enable,checkpoint=merge
> checkpoint=merge,checkpoint=disable
> checkpoint=disable,checkpoint=merge
>
> If the rule/result is clear, it should be documented.
>
> Thanks,
>
>
> >   break;
> >   case Opt_checkpoint_merge:
> > + clear_opt(sbi, DISABLE_CHECKPOINT);
> >   set_opt(sbi, MERGE_CHECKPOINT);
> >   break;
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> > @@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, 
> > char *options, bool is_remount)
> >   return -EINVAL;
> >   }
> >
> > - if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> > - test_opt(sbi, MERGE_CHECKPOINT)) {
> > - f2fs_err(sbi, "checkpoint=merge cannot be used with 
> > checkpoint=disable\n");
> > - return -EINVAL;
> > - }
> > -
> >   /* Not pass down write hints if the number of active logs is lesser
> >* than NR_CURSEG_PERSIST_TYPE.
> >*/
> >

[PATCH] f2fs: prevent setting ioprio of thread not in merge mode

[Daeho Jeong]

From: Daeho Jeong 

It causes a crash to change the ioprio of checkpoint thread not in
checkpoint=merge. I fixed that to prevent setting the ioprio of the
thread when checkpoint=merge is not enabled.

Signed-off-by: Daeho Jeong 
---
 fs/f2fs/sysfs.c | 8 ++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 100608bcd517..e38a7f6921dd 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -357,8 +357,12 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
return -EINVAL;
 
cprc->ckpt_thread_ioprio = IOPRIO_PRIO_VALUE(class, data);
-   ret = set_task_ioprio(cprc->f2fs_issue_ckpt,
-   cprc->ckpt_thread_ioprio);
+   if (test_opt(sbi, MERGE_CHECKPOINT)) {
+   ret = set_task_ioprio(cprc->f2fs_issue_ckpt,
+   cprc->ckpt_thread_ioprio);
+   if (ret)
+   return ret;
+   }
 
return count;
}
-- 
2.30.0.365.g02bc693789-goog

[PATCH] f2fs: fix checkpoint mount option wrong combination

[Daeho Jeong]

From: Daeho Jeong 

As checkpoint=merge comes in, mount option setting related to
checkpoint had been mixed up. Fixed it.

Signed-off-by: Daeho Jeong 
---
 fs/f2fs/super.c | 11 +--
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56696f6cfa86..8231c888c772 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -930,20 +930,25 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
return -EINVAL;
F2FS_OPTION(sbi).unusable_cap_perc = arg;
set_opt(sbi, DISABLE_CHECKPOINT);
+   clear_opt(sbi, MERGE_CHECKPOINT);
break;
case Opt_checkpoint_disable_cap:
if (args->from && match_int(args, &arg))
return -EINVAL;
F2FS_OPTION(sbi).unusable_cap = arg;
set_opt(sbi, DISABLE_CHECKPOINT);
+   clear_opt(sbi, MERGE_CHECKPOINT);
break;
case Opt_checkpoint_disable:
set_opt(sbi, DISABLE_CHECKPOINT);
+   clear_opt(sbi, MERGE_CHECKPOINT);
break;
case Opt_checkpoint_enable:
clear_opt(sbi, DISABLE_CHECKPOINT);
+   clear_opt(sbi, MERGE_CHECKPOINT);
break;
case Opt_checkpoint_merge:
+   clear_opt(sbi, DISABLE_CHECKPOINT);
set_opt(sbi, MERGE_CHECKPOINT);
break;
 #ifdef CONFIG_F2FS_FS_COMPRESSION
@@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, char 
*options, bool is_remount)
return -EINVAL;
}
 
-   if (test_opt(sbi, DISABLE_CHECKPOINT) &&
-   test_opt(sbi, MERGE_CHECKPOINT)) {
-   f2fs_err(sbi, "checkpoint=merge cannot be used with 
checkpoint=disable\n");
-   return -EINVAL;
-   }
-
/* Not pass down write hints if the number of active logs is lesser
 * than NR_CURSEG_PERSIST_TYPE.
 */
-- 
2.30.0.365.g02bc693789-goog

Re: [f2fs-dev] [PATCH v5 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

Yep~

2021년 1월 22일 (금) 오전 10:46, Jaegeuk Kim 님이 작성:
>
> On 01/21, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares. To make this do better, we set the
> > default i/o priority of the kernel daemon to "3", to give one higher
> > priority than other kernel threads. The below verification result
> > explains this.
> > The basic idea has come from https://opensource.samsung.com.
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> > Set "strict_guarantees" to "1" in BFQ tunables
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> >   "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> >done"
> > - thread B => gererating async. I/O
> >   "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> >--filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> >   "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> >fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/  patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong 
> > Signed-off-by: Sungjong Seo 
> > ---
> > v2:
> > - inlined ckpt_req_control into f2fs_sb_info and collected stastics
> >   of checkpoint merge operations
> > v3:
> > - fixed some minor errors and cleaned up f2fs_sync_fs()
> > v4:
> > - added an explanation to raise the default i/o priority of the
> >   checkpoint daemon
> > ---
> >  Documentation/filesystems/f2fs.rst |  10 ++
> >  fs/f2fs/checkpoint.c   | 177 +
> >  fs/f2fs/debug.c|  12 ++
> >  fs/f2fs/f2fs.h |  27 +
> >  fs/f2fs/super.c|  55 +++--
> >  5 files changed, 273 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..9624a0be0364 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,6 +247,16 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > +  Here is another option "merge", which creates a 
> > kernel daemon
> > +  and makes it to merge concurrent checkpoint requests 
> > as much
> > +  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +  we can eliminate the sluggish issue caused by slow 
> > checkpoint
> > +  operation when the checkpoint is done in a process 
> > context in
> > +  a cgroup having low i/o budget and cpu shares. To 
> > make this
> > +  do better, we set the default i/o priority of the 
> > kernel daemon
> > +  to "3", to give one higher priority than other 
> > kernel threads.
> > +  This is the same way to give a I/O priority to the 
> > jbd2
> > +  journaling thread of ext4 filesystem.
> >  compress_algorithm=%s Control compress algorithm, currently f2fs 
> > supports "lzo",
> >"lz4", "zstd" and "lzo-rle" algorithm.
> >  compress_log_size=%u  Support configuring compress cluster size, the size 
> > will
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 897edb7c951a..ef6ad3d1957d 100644
> > --- a/fs/f2fs/checkpoi

Re: [f2fs-dev] [PATCH v5 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

Got it~! :)

2021년 1월 22일 (금) 오전 9:55, Chao Yu 님이 작성:
>
> If there is no update in v5, it will be better to include my Reviewed-by
> tag, please note that. :)
>
> Thanks,
>
> On 2021/1/21 21:45, Daeho Jeong wrote:
> > From: Daeho Jeong
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares. To make this do better, we set the
> > default i/o priority of the kernel daemon to "3", to give one higher
> > priority than other kernel threads. The below verification result
> > explains this.
> > The basic idea has come fromhttps://opensource.samsung.com.
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> > Set "strict_guarantees" to "1" in BFQ tunables
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> >"for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> > done"
> > - thread B => gererating async. I/O
> >"fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> > --filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> >    "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> > fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/  patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong
> > Signed-off-by: Sungjong Seo

[PATCH v5 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

From: Daeho Jeong 

We've added a new mount option "checkpoint=merge", which creates a
kernel daemon and makes it to merge concurrent checkpoint requests as
much as possible to eliminate redundant checkpoint issues. Plus, we
can eliminate the sluggish issue caused by slow checkpoint operation
when the checkpoint is done in a process context in a cgroup having
low i/o budget and cpu shares. To make this do better, we set the
default i/o priority of the kernel daemon to "3", to give one higher
priority than other kernel threads. The below verification result
explains this.
The basic idea has come from https://opensource.samsung.com.

[Verification]
Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
Set "strict_guarantees" to "1" in BFQ tunables

In "fg" cgroup,
- thread A => trigger 1000 checkpoint operations
  "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
   done"
- thread B => gererating async. I/O
  "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
   --filename=test_img --name=test"

In "bg" cgroup,
- thread C => trigger repeated checkpoint operations
  "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
   fsync test_dir2; done"

We've measured thread A's execution time.

[ w/o patch ]
Elapsed Time: Avg. 68 seconds
[ w/  patch ]
Elapsed Time: Avg. 48 seconds

Signed-off-by: Daeho Jeong 
Signed-off-by: Sungjong Seo 
---
v2:
- inlined ckpt_req_control into f2fs_sb_info and collected stastics
  of checkpoint merge operations
v3:
- fixed some minor errors and cleaned up f2fs_sync_fs()
v4:
- added an explanation to raise the default i/o priority of the
  checkpoint daemon
---
 Documentation/filesystems/f2fs.rst |  10 ++
 fs/f2fs/checkpoint.c   | 177 +
 fs/f2fs/debug.c|  12 ++
 fs/f2fs/f2fs.h |  27 +
 fs/f2fs/super.c|  55 +++--
 5 files changed, 273 insertions(+), 8 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index dae15c96e659..9624a0be0364 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,6 +247,16 @@ checkpoint=%s[:%u[%]]   Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
+Here is another option "merge", which creates a kernel 
daemon
+and makes it to merge concurrent checkpoint requests 
as much
+as possible to eliminate redundant checkpoint issues. 
Plus,
+we can eliminate the sluggish issue caused by slow 
checkpoint
+operation when the checkpoint is done in a process 
context in
+a cgroup having low i/o budget and cpu shares. To make 
this
+do better, we set the default i/o priority of the 
kernel daemon
+to "3", to give one higher priority than other kernel 
threads.
+This is the same way to give a I/O priority to the jbd2
+journaling thread of ext4 filesystem.
 compress_algorithm=%s   Control compress algorithm, currently f2fs supports 
"lzo",
 "lz4", "zstd" and "lzo-rle" algorithm.
 compress_log_size=%uSupport configuring compress cluster size, the size 
will
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 897edb7c951a..ef6ad3d1957d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "node.h"
@@ -20,6 +21,8 @@
 #include "trace.h"
 #include 
 
+#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
+
 static struct kmem_cache *ino_entry_slab;
 struct kmem_cache *f2fs_inode_entry_slab;
 
@@ -1707,3 +1710,177 @@ void f2fs_destroy_checkpoint_caches(void)
kmem_cache_destroy(ino_entry_slab);
kmem_cache_destroy(f2fs_inode_entry_slab);
 }
+
+static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
+{
+   struct cp_control cpc = { .reason = CP_SYNC, };
+   int err;
+
+   down_write(&sbi->gc_lock);
+   err = f2fs_write_checkpoint(sbi, &cpc);
+   up_write(&sbi->gc_lock);
+
+   return err;
+}
+
+static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi)
+{
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   struct ckpt_req *

[PATCH v5 2/2] f2fs: add ckpt_thread_ioprio sysfs node

[Daeho Jeong]

From: Daeho Jeong 

Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.

Signed-off-by: Daeho Jeong 
---
v2:
- adapt to inlining ckpt_req_control of f2fs_sb_info
v5:
- initialized cprc->ckpt_thread_ioprio
---
 Documentation/ABI/testing/sysfs-fs-f2fs |  8 
 fs/f2fs/checkpoint.c|  3 +-
 fs/f2fs/f2fs.h  |  1 +
 fs/f2fs/sysfs.c | 51 +
 4 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3dfee94e0618..0c48b2e7dfd4 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -377,3 +377,11 @@ Description:   This gives a control to limit the bio 
size in f2fs.
Default is zero, which will follow underlying block layer limit,
whereas, if it has a certain bytes value, f2fs won't submit a
bio larger than that size.
+What:  /sys/fs/f2fs//ckpt_thread_ioprio
+Date:  January 2021
+Contact:   "Daeho Jeong" 
+Description:   Give a way to change checkpoint merge daemon's io priority.
+   Its default value is "be,3", which means "BE" I/O class and
+   I/O priority "3". We can select the class between "rt" and "be",
+   and set the I/O priority within valid range of it. "," delimiter
+   is necessary in between I/O class and priority number.
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index ef6ad3d1957d..a3549923762d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1854,7 +1854,7 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
return PTR_ERR(cprc->f2fs_issue_ckpt);
}
 
-   set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
+   set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
 
return 0;
 }
@@ -1880,6 +1880,7 @@ void f2fs_init_ckpt_req_control(struct f2fs_sb_info *sbi)
atomic_set(&cprc->issued_ckpt, 0);
atomic_set(&cprc->total_ckpt, 0);
atomic_set(&cprc->queued_ckpt, 0);
+   cprc->ckpt_thread_ioprio = DEFAULT_CHECKPOINT_IOPRIO;
init_waitqueue_head(&cprc->ckpt_wait_queue);
init_llist_head(&cprc->issue_list);
spin_lock_init(&cprc->stat_lock);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f2ae075aa723..517eb0eda638 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -276,6 +276,7 @@ struct ckpt_req {
 
 struct ckpt_req_control {
struct task_struct *f2fs_issue_ckpt;/* checkpoint task */
+   int ckpt_thread_ioprio; /* checkpoint merge thread 
ioprio */
wait_queue_head_t ckpt_wait_queue;  /* waiting queue for wake-up */
atomic_t issued_ckpt;   /* # of actually issued ckpts */
atomic_t total_ckpt;/* # of total ckpts */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 30bae57428d1..ddd70395148d 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -11,6 +11,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "segment.h"
@@ -34,6 +35,7 @@ enum {
FAULT_INFO_TYPE,/* struct f2fs_fault_info */
 #endif
RESERVED_BLOCKS,/* struct f2fs_sb_info */
+   CPRC_INFO,  /* struct ckpt_req_control */
 };
 
 struct f2fs_attr {
@@ -70,6 +72,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, 
int struct_type)
else if (struct_type == STAT_INFO)
return (unsigned char *)F2FS_STAT(sbi);
 #endif
+   else if (struct_type == CPRC_INFO)
+   return (unsigned char *)&sbi->cprc_info;
return NULL;
 }
 
@@ -255,6 +259,23 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
return len;
}
 
+   if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   int len = 0;
+   int class = IOPRIO_PRIO_CLASS(cprc->ckpt_thread_ioprio);
+   int data = IOPRIO_PRIO_DATA(cprc->ckpt_thread_ioprio);
+
+   if (class == IOPRIO_CLASS_RT)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "rt,");
+   else if (class == IOPRIO_CLASS_BE)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "be,");
+   el

Re: [f2fs-dev] [PATCH v2 2/2] f2fs: add ckpt_thread_ioprio sysfs node

[Daeho Jeong]

Oops, it disappeared while versioning up...

2021년 1월 21일 (목) 오후 7:30, Chao Yu 님이 작성:
>
> On 2021/1/14 14:23, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
> > merge daemon's io priority. Its default value is "be,3", which means
> > "BE" I/O class and I/O priority "3". We can select the class between "rt"
> > and "be", and set the I/O priority within valid range of it.
> > "," delimiter is necessary in between I/O class and priority number.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> > v2:
> > - adapt to inlining ckpt_req_control of f2fs_sb_info
> > ---
> >   Documentation/ABI/testing/sysfs-fs-f2fs |  8 
> >   fs/f2fs/checkpoint.c|  2 +-
> >   fs/f2fs/f2fs.h  |  1 +
> >   fs/f2fs/sysfs.c | 51 +
> >   4 files changed, 61 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
> > b/Documentation/ABI/testing/sysfs-fs-f2fs
> > index 3dfee94e0618..0c48b2e7dfd4 100644
> > --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> > @@ -377,3 +377,11 @@ Description: This gives a control to limit the bio 
> > size in f2fs.
> >   Default is zero, which will follow underlying block layer 
> > limit,
> >   whereas, if it has a certain bytes value, f2fs won't submit a
> >   bio larger than that size.
> > +What:/sys/fs/f2fs//ckpt_thread_ioprio
> > +Date:January 2021
> > +Contact: "Daeho Jeong" 
> > +Description: Give a way to change checkpoint merge daemon's io priority.
> > + Its default value is "be,3", which means "BE" I/O class and
> > + I/O priority "3". We can select the class between "rt" and 
> > "be",
> > + and set the I/O priority within valid range of it. "," 
> > delimiter
> > + is necessary in between I/O class and priority number.
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index e0668cec3b80..62bd6f449bb7 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -1840,7 +1840,7 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
> >   if (IS_ERR(cprc->f2fs_issue_ckpt))
> >   return PTR_ERR(cprc->f2fs_issue_ckpt);
> >
> > - set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
> > + set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
>
> Where do we set default value of cprc->ckpt_thread_ioprio? I guess it should
> be f2fs_init_ckpt_req_control()?
>
> Thanks,

Re: [f2fs-dev] [PATCH v4 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

Sorry, I think you were definitely confused.

There is no change for 2/2. So I didn't send it.

Next time, I am going to send it all, even though some of them don't
have changes.

2021년 1월 20일 (수) 오전 4:08, Jaegeuk Kim 님이 작성:
>
> Is there v4 2/2?
>
> On 01/19, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares. To make this do better, we set the
> > default i/o priority of the kernel daemon to "3", to give one higher
> > priority than other kernel threads. The below verification result
> > explains this.
> > The basic idea has come from https://opensource.samsung.com.
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> > Set "strict_guarantees" to "1" in BFQ tunables
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> >   "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> >done"
> > - thread B => gererating async. I/O
> >   "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> >--filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> >   "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> >fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/  patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong 
> > Signed-off-by: Sungjong Seo 
> > ---
> > v2:
> > - inlined ckpt_req_control into f2fs_sb_info and collected stastics
> >   of checkpoint merge operations
> > v3:
> > - fixed some minor errors and cleaned up f2fs_sync_fs()
> > v4:
> > - added an explanation to raise the default i/o priority of the
> >   checkpoint daemon
> > ---
> >  Documentation/filesystems/f2fs.rst |  10 ++
> >  fs/f2fs/checkpoint.c   | 177 +
> >  fs/f2fs/debug.c|  12 ++
> >  fs/f2fs/f2fs.h |  27 +
> >  fs/f2fs/super.c|  55 +++--
> >  5 files changed, 273 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..9624a0be0364 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,6 +247,16 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > +  Here is another option "merge", which creates a 
> > kernel daemon
> > +  and makes it to merge concurrent checkpoint requests 
> > as much
> > +  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +  we can eliminate the sluggish issue caused by slow 
> > checkpoint
> > +  operation when the checkpoint is done in a process 
> > context in
> > +  a cgroup having low i/o budget and cpu shares. To 
> > make this
> > +  do better, we set the default i/o priority of the 
> > kernel daemon
> > +  to "3", to give one higher priority than other 
> > kernel threads.
> > +  This is the same way to give a I/O priority to the 
> > jbd2
> > +  journaling thread of ext4 filesystem.
> >  compress_algorithm=%s Control compress algorithm, currently f2fs 
> > supports "lzo",
> >"lz4", "zstd" and "lzo-rle" algorithm.
> >  compress_log_size=%u  Support c

[PATCH v4 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

From: Daeho Jeong 

We've added a new mount option "checkpoint=merge", which creates a
kernel daemon and makes it to merge concurrent checkpoint requests as
much as possible to eliminate redundant checkpoint issues. Plus, we
can eliminate the sluggish issue caused by slow checkpoint operation
when the checkpoint is done in a process context in a cgroup having
low i/o budget and cpu shares. To make this do better, we set the
default i/o priority of the kernel daemon to "3", to give one higher
priority than other kernel threads. The below verification result
explains this.
The basic idea has come from https://opensource.samsung.com.

[Verification]
Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
Set "strict_guarantees" to "1" in BFQ tunables

In "fg" cgroup,
- thread A => trigger 1000 checkpoint operations
  "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
   done"
- thread B => gererating async. I/O
  "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
   --filename=test_img --name=test"

In "bg" cgroup,
- thread C => trigger repeated checkpoint operations
  "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
   fsync test_dir2; done"

We've measured thread A's execution time.

[ w/o patch ]
Elapsed Time: Avg. 68 seconds
[ w/  patch ]
Elapsed Time: Avg. 48 seconds

Signed-off-by: Daeho Jeong 
Signed-off-by: Sungjong Seo 
---
v2:
- inlined ckpt_req_control into f2fs_sb_info and collected stastics
  of checkpoint merge operations
v3:
- fixed some minor errors and cleaned up f2fs_sync_fs()
v4:
- added an explanation to raise the default i/o priority of the
  checkpoint daemon
---
 Documentation/filesystems/f2fs.rst |  10 ++
 fs/f2fs/checkpoint.c   | 177 +
 fs/f2fs/debug.c|  12 ++
 fs/f2fs/f2fs.h |  27 +
 fs/f2fs/super.c|  55 +++--
 5 files changed, 273 insertions(+), 8 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index dae15c96e659..9624a0be0364 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,6 +247,16 @@ checkpoint=%s[:%u[%]]   Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
+Here is another option "merge", which creates a kernel 
daemon
+and makes it to merge concurrent checkpoint requests 
as much
+as possible to eliminate redundant checkpoint issues. 
Plus,
+we can eliminate the sluggish issue caused by slow 
checkpoint
+operation when the checkpoint is done in a process 
context in
+a cgroup having low i/o budget and cpu shares. To make 
this
+do better, we set the default i/o priority of the 
kernel daemon
+to "3", to give one higher priority than other kernel 
threads.
+This is the same way to give a I/O priority to the jbd2
+journaling thread of ext4 filesystem.
 compress_algorithm=%s   Control compress algorithm, currently f2fs supports 
"lzo",
 "lz4", "zstd" and "lzo-rle" algorithm.
 compress_log_size=%uSupport configuring compress cluster size, the size 
will
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 897edb7c951a..ef6ad3d1957d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "node.h"
@@ -20,6 +21,8 @@
 #include "trace.h"
 #include 
 
+#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
+
 static struct kmem_cache *ino_entry_slab;
 struct kmem_cache *f2fs_inode_entry_slab;
 
@@ -1707,3 +1710,177 @@ void f2fs_destroy_checkpoint_caches(void)
kmem_cache_destroy(ino_entry_slab);
kmem_cache_destroy(f2fs_inode_entry_slab);
 }
+
+static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
+{
+   struct cp_control cpc = { .reason = CP_SYNC, };
+   int err;
+
+   down_write(&sbi->gc_lock);
+   err = f2fs_write_checkpoint(sbi, &cpc);
+   up_write(&sbi->gc_lock);
+
+   return err;
+}
+
+static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi)
+{
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   struct ckpt_req *

[PATCH v3 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

From: Daeho Jeong 

We've added a new mount option "checkpoint=merge", which creates a
kernel daemon and makes it to merge concurrent checkpoint requests as
much as possible to eliminate redundant checkpoint issues. Plus, we
can eliminate the sluggish issue caused by slow checkpoint operation
when the checkpoint is done in a process context in a cgroup having
low i/o budget and cpu shares, and The below verification result
explains this.
The basic idea has come from https://opensource.samsung.com.

[Verification]
Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
Set "strict_guarantees" to "1" in BFQ tunables

In "fg" cgroup,
- thread A => trigger 1000 checkpoint operations
  "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
   done"
- thread B => gererating async. I/O
  "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
   --filename=test_img --name=test"

In "bg" cgroup,
- thread C => trigger repeated checkpoint operations
  "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
   fsync test_dir2; done"

We've measured thread A's execution time.

[ w/o patch ]
Elapsed Time: Avg. 68 seconds
[ w/  patch ]
Elapsed Time: Avg. 48 seconds

Signed-off-by: Daeho Jeong 
Signed-off-by: Sungjong Seo 
---
v2:
- inlined ckpt_req_control into f2fs_sb_info and collected stastics
  of checkpoint merge operations
v3:
- fixed some minor errors and cleaned up f2fs_sync_fs()
---
 Documentation/filesystems/f2fs.rst |   6 +
 fs/f2fs/checkpoint.c   | 177 +
 fs/f2fs/debug.c|  12 ++
 fs/f2fs/f2fs.h |  27 +
 fs/f2fs/super.c|  55 +++--
 5 files changed, 269 insertions(+), 8 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index dae15c96e659..bccc021bf31a 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]]   Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
+Here is another option "merge", which creates a kernel 
daemon
+and makes it to merge concurrent checkpoint requests 
as much
+as possible to eliminate redundant checkpoint issues. 
Plus,
+we can eliminate the sluggish issue caused by slow 
checkpoint
+operation when the checkpoint is done in a process 
context in
+a cgroup having low i/o budget and cpu shares.
 compress_algorithm=%s   Control compress algorithm, currently f2fs supports 
"lzo",
 "lz4", "zstd" and "lzo-rle" algorithm.
 compress_log_size=%uSupport configuring compress cluster size, the size 
will
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 897edb7c951a..ef6ad3d1957d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "node.h"
@@ -20,6 +21,8 @@
 #include "trace.h"
 #include 
 
+#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
+
 static struct kmem_cache *ino_entry_slab;
 struct kmem_cache *f2fs_inode_entry_slab;
 
@@ -1707,3 +1710,177 @@ void f2fs_destroy_checkpoint_caches(void)
kmem_cache_destroy(ino_entry_slab);
kmem_cache_destroy(f2fs_inode_entry_slab);
 }
+
+static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
+{
+   struct cp_control cpc = { .reason = CP_SYNC, };
+   int err;
+
+   down_write(&sbi->gc_lock);
+   err = f2fs_write_checkpoint(sbi, &cpc);
+   up_write(&sbi->gc_lock);
+
+   return err;
+}
+
+static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi)
+{
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   struct ckpt_req *req, *next;
+   struct llist_node *dispatch_list;
+   u64 sum_diff = 0, diff, count = 0;
+   int ret;
+
+   dispatch_list = llist_del_all(&cprc->issue_list);
+   if (!dispatch_list)
+   return;
+   dispatch_list = llist_reverse_order(dispatch_list);
+
+   ret = __write_checkpoint_sync(sbi);
+   atomic_inc(&cprc->issued_ckpt);
+
+   llist_for_each_entry_safe(req, next, dispatch_list, llnode) {
+   diff = (u64)ktime_ms_delta(ktime_get(), req->queue_time);
+   req->ret = ret;
+   

Re: [PATCH v3] f2fs: add ckpt_thread_ioprio sysfs node

[Daeho Jeong]

Sorry, ignore this.
I've sent this wrong. :(

2021년 1월 16일 (토) 오전 9:58, Daeho Jeong 님이 작성:
>
> From: Daeho Jeong 
>
> Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
> merge daemon's io priority. Its default value is "be,3", which means
> "BE" I/O class and I/O priority "3". We can select the class between "rt"
> and "be", and set the I/O priority within valid range of it.
> "," delimiter is necessary in between I/O class and priority number.
>
> Signed-off-by: Daeho Jeong 
> ---
> v2:
> - adapt to inlining ckpt_req_control of f2fs_sb_info
> ---
>  Documentation/ABI/testing/sysfs-fs-f2fs |  8 
>  fs/f2fs/checkpoint.c|  2 +-
>  fs/f2fs/f2fs.h  |  1 +
>  fs/f2fs/sysfs.c | 51 +
>  4 files changed, 61 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
> b/Documentation/ABI/testing/sysfs-fs-f2fs
> index 3dfee94e0618..0c48b2e7dfd4 100644
> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> @@ -377,3 +377,11 @@ Description:   This gives a control to limit the bio 
> size in f2fs.
> Default is zero, which will follow underlying block layer 
> limit,
> whereas, if it has a certain bytes value, f2fs won't submit a
> bio larger than that size.
> +What:  /sys/fs/f2fs//ckpt_thread_ioprio
> +Date:  January 2021
> +Contact:   "Daeho Jeong" 
> +Description:   Give a way to change checkpoint merge daemon's io priority.
> +   Its default value is "be,3", which means "BE" I/O class and
> +   I/O priority "3". We can select the class between "rt" and 
> "be",
> +   and set the I/O priority within valid range of it. "," 
> delimiter
> +   is necessary in between I/O class and priority number.
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index ef6ad3d1957d..30e3fe161bb4 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1854,7 +1854,7 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
> return PTR_ERR(cprc->f2fs_issue_ckpt);
> }
>
> -   set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
> +   set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
>
> return 0;
>  }
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index f2ae075aa723..517eb0eda638 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -276,6 +276,7 @@ struct ckpt_req {
>
>  struct ckpt_req_control {
> struct task_struct *f2fs_issue_ckpt;/* checkpoint task */
> +   int ckpt_thread_ioprio; /* checkpoint merge thread 
> ioprio */
> wait_queue_head_t ckpt_wait_queue;  /* waiting queue for wake-up 
> */
> atomic_t issued_ckpt;   /* # of actually issued ckpts */
> atomic_t total_ckpt;/* # of total ckpts */
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 30bae57428d1..ddd70395148d 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -11,6 +11,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>
>  #include "f2fs.h"
>  #include "segment.h"
> @@ -34,6 +35,7 @@ enum {
> FAULT_INFO_TYPE,/* struct f2fs_fault_info */
>  #endif
> RESERVED_BLOCKS,/* struct f2fs_sb_info */
> +   CPRC_INFO,  /* struct ckpt_req_control */
>  };
>
>  struct f2fs_attr {
> @@ -70,6 +72,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info 
> *sbi, int struct_type)
> else if (struct_type == STAT_INFO)
> return (unsigned char *)F2FS_STAT(sbi);
>  #endif
> +   else if (struct_type == CPRC_INFO)
> +   return (unsigned char *)&sbi->cprc_info;
> return NULL;
>  }
>
> @@ -255,6 +259,23 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
> return len;
> }
>
> +   if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
> +   struct ckpt_req_control *cprc = &sbi->cprc_info;
> +   int len = 0;
> +   int class = IOPRIO_PRIO_CLASS(cprc->ckpt_thread_ioprio);
> +   int data = IOPRIO_PRIO_DATA(cprc->ckpt_thread_ioprio);
> +
> +   if (class == IOPRIO_CLASS_RT)
> +   len += scnprintf(buf + len, PAGE_SIZE - len, "rt,");
> + 

[PATCH v3] f2fs: add ckpt_thread_ioprio sysfs node

[Daeho Jeong]

From: Daeho Jeong 

Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.

Signed-off-by: Daeho Jeong 
---
v2:
- adapt to inlining ckpt_req_control of f2fs_sb_info
---
 Documentation/ABI/testing/sysfs-fs-f2fs |  8 
 fs/f2fs/checkpoint.c|  2 +-
 fs/f2fs/f2fs.h  |  1 +
 fs/f2fs/sysfs.c | 51 +
 4 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3dfee94e0618..0c48b2e7dfd4 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -377,3 +377,11 @@ Description:   This gives a control to limit the bio 
size in f2fs.
Default is zero, which will follow underlying block layer limit,
whereas, if it has a certain bytes value, f2fs won't submit a
bio larger than that size.
+What:  /sys/fs/f2fs//ckpt_thread_ioprio
+Date:  January 2021
+Contact:   "Daeho Jeong" 
+Description:   Give a way to change checkpoint merge daemon's io priority.
+   Its default value is "be,3", which means "BE" I/O class and
+   I/O priority "3". We can select the class between "rt" and "be",
+   and set the I/O priority within valid range of it. "," delimiter
+   is necessary in between I/O class and priority number.
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index ef6ad3d1957d..30e3fe161bb4 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1854,7 +1854,7 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
return PTR_ERR(cprc->f2fs_issue_ckpt);
}
 
-   set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
+   set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
 
return 0;
 }
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f2ae075aa723..517eb0eda638 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -276,6 +276,7 @@ struct ckpt_req {
 
 struct ckpt_req_control {
struct task_struct *f2fs_issue_ckpt;/* checkpoint task */
+   int ckpt_thread_ioprio; /* checkpoint merge thread 
ioprio */
wait_queue_head_t ckpt_wait_queue;  /* waiting queue for wake-up */
atomic_t issued_ckpt;   /* # of actually issued ckpts */
atomic_t total_ckpt;/* # of total ckpts */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 30bae57428d1..ddd70395148d 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -11,6 +11,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "segment.h"
@@ -34,6 +35,7 @@ enum {
FAULT_INFO_TYPE,/* struct f2fs_fault_info */
 #endif
RESERVED_BLOCKS,/* struct f2fs_sb_info */
+   CPRC_INFO,  /* struct ckpt_req_control */
 };
 
 struct f2fs_attr {
@@ -70,6 +72,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, 
int struct_type)
else if (struct_type == STAT_INFO)
return (unsigned char *)F2FS_STAT(sbi);
 #endif
+   else if (struct_type == CPRC_INFO)
+   return (unsigned char *)&sbi->cprc_info;
return NULL;
 }
 
@@ -255,6 +259,23 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
return len;
}
 
+   if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   int len = 0;
+   int class = IOPRIO_PRIO_CLASS(cprc->ckpt_thread_ioprio);
+   int data = IOPRIO_PRIO_DATA(cprc->ckpt_thread_ioprio);
+
+   if (class == IOPRIO_CLASS_RT)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "rt,");
+   else if (class == IOPRIO_CLASS_BE)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "be,");
+   else
+   return -EINVAL;
+
+   len += scnprintf(buf + len, PAGE_SIZE - len, "%d\n", data);
+   return len;
+   }
+
ui = (unsigned int *)(ptr + a->offset);
 
return sprintf(buf, "%u\n", *ui);
@@ -308,6 +329,34 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
return ret ? ret : count;
}
 
+   if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+   co

Re: [f2fs-dev] [PATCH v2 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

2021년 1월 15일 (금) 오후 11:00, Daeho Jeong 님이 작성:
>
> 2021년 1월 15일 (금) 오후 6:22, Chao Yu 님이 작성:
> >
> > On 2021/1/14 14:23, Daeho Jeong wrote:
> > > From: Daeho Jeong 
> > >
> > > We've added a new mount option "checkpoint=merge", which creates a
> > > kernel daemon and makes it to merge concurrent checkpoint requests as
> > > much as possible to eliminate redundant checkpoint issues. Plus, we
> > > can eliminate the sluggish issue caused by slow checkpoint operation
> > > when the checkpoint is done in a process context in a cgroup having
> > > low i/o budget and cpu shares, and The below verification result
> > > explains this.
> > > The basic idea has come from https://opensource.samsung.com.
> > >
> > > [Verification]
> > > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> > > Set "strict_guarantees" to "1" in BFQ tunables
> > >
> > > In "fg" cgroup,
> > > - thread A => trigger 1000 checkpoint operations
> > >"for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> > > done"
> > > - thread B => gererating async. I/O
> > >"fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> > > --filename=test_img --name=test"
> > >
> > > In "bg" cgroup,
> > > - thread C => trigger repeated checkpoint operations
> > >"echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> > > fsync test_dir2; done"
> > >
> > > We've measured thread A's execution time.
> > >
> > > [ w/o patch ]
> > > Elapsed Time: Avg. 68 seconds
> > > [ w/  patch ]
> > > Elapsed Time: Avg. 48 seconds
> > >
> > > Signed-off-by: Daeho Jeong 
> > > Signed-off-by: Sungjong Seo 
> > > ---
> > > v2:
> > > - inlined ckpt_req_control into f2fs_sb_info and collected stastics
> > >of checkpoint merge operations
> > > ---
> > >   Documentation/filesystems/f2fs.rst |   6 ++
> > >   fs/f2fs/checkpoint.c   | 163 +
> > >   fs/f2fs/debug.c|  12 +++
> > >   fs/f2fs/f2fs.h |  27 +
> > >   fs/f2fs/super.c|  56 +-
> > >   5 files changed, 260 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/Documentation/filesystems/f2fs.rst 
> > > b/Documentation/filesystems/f2fs.rst
> > > index dae15c96e659..bccc021bf31a 100644
> > > --- a/Documentation/filesystems/f2fs.rst
> > > +++ b/Documentation/filesystems/f2fs.rst
> > > @@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn 
> > > off checkpointing. Set to "enabl
> > >hide up to all remaining free space. The actual 
> > > space that
> > >would be unusable can be viewed at 
> > > /sys/fs/f2fs//unusable
> > >This space is reclaimed once checkpoint=enable.
> > > +  Here is another option "merge", which creates a 
> > > kernel daemon
> > > +  and makes it to merge concurrent checkpoint 
> > > requests as much
> > > +  as possible to eliminate redundant checkpoint 
> > > issues. Plus,
> > > +  we can eliminate the sluggish issue caused by slow 
> > > checkpoint
> > > +  operation when the checkpoint is done in a process 
> > > context in
> > > +  a cgroup having low i/o budget and cpu shares.
> > >   compress_algorithm=%sControl compress algorithm, currently f2fs 
> > > supports "lzo",
> > >"lz4", "zstd" and "lzo-rle" algorithm.
> > >   compress_log_size=%u Support configuring compress cluster size, 
> > > the size will
> > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > > index 897edb7c951a..e0668cec3b80 100644
> > > --- a/fs/f2fs/checkpoint.c
> > > +++ b/fs/f2fs/checkpoint.c
> > > @@ -13,6 +13,7 @@
> > >   #include 
> > >   #include 
> > >   #include 
> > > +#include 
> > >
> > >   #include "f2fs.h"
> > >   #include "node.h"
&g

Re: [f2fs-dev] [PATCH v2 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

2021년 1월 15일 (금) 오후 6:22, Chao Yu 님이 작성:
>
> On 2021/1/14 14:23, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares, and The below verification result
> > explains this.
> > The basic idea has come from https://opensource.samsung.com.
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> > Set "strict_guarantees" to "1" in BFQ tunables
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> >"for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> > done"
> > - thread B => gererating async. I/O
> >"fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> > --filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> >"echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> > fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/  patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong 
> > Signed-off-by: Sungjong Seo 
> > ---
> > v2:
> > - inlined ckpt_req_control into f2fs_sb_info and collected stastics
> >of checkpoint merge operations
> > ---
> >   Documentation/filesystems/f2fs.rst |   6 ++
> >   fs/f2fs/checkpoint.c   | 163 +
> >   fs/f2fs/debug.c|  12 +++
> >   fs/f2fs/f2fs.h |  27 +
> >   fs/f2fs/super.c|  56 +-
> >   5 files changed, 260 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..bccc021bf31a 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > +  Here is another option "merge", which creates a 
> > kernel daemon
> > +  and makes it to merge concurrent checkpoint requests 
> > as much
> > +  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +  we can eliminate the sluggish issue caused by slow 
> > checkpoint
> > +  operation when the checkpoint is done in a process 
> > context in
> > +  a cgroup having low i/o budget and cpu shares.
> >   compress_algorithm=%sControl compress algorithm, currently f2fs 
> > supports "lzo",
> >"lz4", "zstd" and "lzo-rle" algorithm.
> >   compress_log_size=%u Support configuring compress cluster size, 
> > the size will
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 897edb7c951a..e0668cec3b80 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -13,6 +13,7 @@
> >   #include 
> >   #include 
> >   #include 
> > +#include 
> >
> >   #include "f2fs.h"
> >   #include "node.h"
> > @@ -20,6 +21,8 @@
> >   #include "trace.h"
> >   #include 
> >
> > +#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
> > +
> >   static struct kmem_cache *ino_entry_slab;
> >   struct kmem_cache *f2fs_inode_entry_slab;
> >
> > @@ -1707,3 +1710,163 @@ void f2fs_destroy_checkpoint_caches(void)
> >   kmem_cache_destroy(ino_entry_slab);
> >   kmem_cache_destroy(f2fs_inode_entry_slab);
>

[PATCH v2 2/2] f2fs: add ckpt_thread_ioprio sysfs node

[Daeho Jeong]

From: Daeho Jeong 

Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.

Signed-off-by: Daeho Jeong 
---
v2:
- adapt to inlining ckpt_req_control of f2fs_sb_info
---
 Documentation/ABI/testing/sysfs-fs-f2fs |  8 
 fs/f2fs/checkpoint.c|  2 +-
 fs/f2fs/f2fs.h  |  1 +
 fs/f2fs/sysfs.c | 51 +
 4 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3dfee94e0618..0c48b2e7dfd4 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -377,3 +377,11 @@ Description:   This gives a control to limit the bio 
size in f2fs.
Default is zero, which will follow underlying block layer limit,
whereas, if it has a certain bytes value, f2fs won't submit a
bio larger than that size.
+What:  /sys/fs/f2fs//ckpt_thread_ioprio
+Date:  January 2021
+Contact:   "Daeho Jeong" 
+Description:   Give a way to change checkpoint merge daemon's io priority.
+   Its default value is "be,3", which means "BE" I/O class and
+   I/O priority "3". We can select the class between "rt" and "be",
+   and set the I/O priority within valid range of it. "," delimiter
+   is necessary in between I/O class and priority number.
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index e0668cec3b80..62bd6f449bb7 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1840,7 +1840,7 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
if (IS_ERR(cprc->f2fs_issue_ckpt))
return PTR_ERR(cprc->f2fs_issue_ckpt);
 
-   set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
+   set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
 
return 0;
 }
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f2ae075aa723..517eb0eda638 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -276,6 +276,7 @@ struct ckpt_req {
 
 struct ckpt_req_control {
struct task_struct *f2fs_issue_ckpt;/* checkpoint task */
+   int ckpt_thread_ioprio; /* checkpoint merge thread 
ioprio */
wait_queue_head_t ckpt_wait_queue;  /* waiting queue for wake-up */
atomic_t issued_ckpt;   /* # of actually issued ckpts */
atomic_t total_ckpt;/* # of total ckpts */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 30bae57428d1..ddd70395148d 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -11,6 +11,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "segment.h"
@@ -34,6 +35,7 @@ enum {
FAULT_INFO_TYPE,/* struct f2fs_fault_info */
 #endif
RESERVED_BLOCKS,/* struct f2fs_sb_info */
+   CPRC_INFO,  /* struct ckpt_req_control */
 };
 
 struct f2fs_attr {
@@ -70,6 +72,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, 
int struct_type)
else if (struct_type == STAT_INFO)
return (unsigned char *)F2FS_STAT(sbi);
 #endif
+   else if (struct_type == CPRC_INFO)
+   return (unsigned char *)&sbi->cprc_info;
return NULL;
 }
 
@@ -255,6 +259,23 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
return len;
}
 
+   if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   int len = 0;
+   int class = IOPRIO_PRIO_CLASS(cprc->ckpt_thread_ioprio);
+   int data = IOPRIO_PRIO_DATA(cprc->ckpt_thread_ioprio);
+
+   if (class == IOPRIO_CLASS_RT)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "rt,");
+   else if (class == IOPRIO_CLASS_BE)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "be,");
+   else
+   return -EINVAL;
+
+   len += scnprintf(buf + len, PAGE_SIZE - len, "%d\n", data);
+   return len;
+   }
+
ui = (unsigned int *)(ptr + a->offset);
 
return sprintf(buf, "%u\n", *ui);
@@ -308,6 +329,34 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
return ret ? ret : count;
}
 
+   if (!strcmp(a->attr.name, 

[PATCH v2 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

From: Daeho Jeong 

We've added a new mount option "checkpoint=merge", which creates a
kernel daemon and makes it to merge concurrent checkpoint requests as
much as possible to eliminate redundant checkpoint issues. Plus, we
can eliminate the sluggish issue caused by slow checkpoint operation
when the checkpoint is done in a process context in a cgroup having
low i/o budget and cpu shares, and The below verification result
explains this.
The basic idea has come from https://opensource.samsung.com.

[Verification]
Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
Set "strict_guarantees" to "1" in BFQ tunables

In "fg" cgroup,
- thread A => trigger 1000 checkpoint operations
  "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
   done"
- thread B => gererating async. I/O
  "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
   --filename=test_img --name=test"

In "bg" cgroup,
- thread C => trigger repeated checkpoint operations
  "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
   fsync test_dir2; done"

We've measured thread A's execution time.

[ w/o patch ]
Elapsed Time: Avg. 68 seconds
[ w/  patch ]
Elapsed Time: Avg. 48 seconds

Signed-off-by: Daeho Jeong 
Signed-off-by: Sungjong Seo 
---
v2:
- inlined ckpt_req_control into f2fs_sb_info and collected stastics
  of checkpoint merge operations
---
 Documentation/filesystems/f2fs.rst |   6 ++
 fs/f2fs/checkpoint.c   | 163 +
 fs/f2fs/debug.c|  12 +++
 fs/f2fs/f2fs.h |  27 +
 fs/f2fs/super.c|  56 +-
 5 files changed, 260 insertions(+), 4 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index dae15c96e659..bccc021bf31a 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]]   Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
+Here is another option "merge", which creates a kernel 
daemon
+and makes it to merge concurrent checkpoint requests 
as much
+as possible to eliminate redundant checkpoint issues. 
Plus,
+we can eliminate the sluggish issue caused by slow 
checkpoint
+operation when the checkpoint is done in a process 
context in
+a cgroup having low i/o budget and cpu shares.
 compress_algorithm=%s   Control compress algorithm, currently f2fs supports 
"lzo",
 "lz4", "zstd" and "lzo-rle" algorithm.
 compress_log_size=%uSupport configuring compress cluster size, the size 
will
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 897edb7c951a..e0668cec3b80 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "node.h"
@@ -20,6 +21,8 @@
 #include "trace.h"
 #include 
 
+#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
+
 static struct kmem_cache *ino_entry_slab;
 struct kmem_cache *f2fs_inode_entry_slab;
 
@@ -1707,3 +1710,163 @@ void f2fs_destroy_checkpoint_caches(void)
kmem_cache_destroy(ino_entry_slab);
kmem_cache_destroy(f2fs_inode_entry_slab);
 }
+
+static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
+{
+   struct cp_control cpc = { .reason = CP_SYNC, };
+   int err;
+
+   down_write(&sbi->gc_lock);
+   err = f2fs_write_checkpoint(sbi, &cpc);
+   up_write(&sbi->gc_lock);
+
+   return err;
+}
+
+static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi)
+{
+   struct ckpt_req_control *cprc = &sbi->cprc_info;
+   struct ckpt_req *req, *next;
+   struct llist_node *dispatch_list;
+   u64 sum_diff = 0, diff, count = 0;
+   int ret;
+
+   dispatch_list = llist_del_all(&cprc->issue_list);
+   if (!dispatch_list)
+   return;
+   dispatch_list = llist_reverse_order(dispatch_list);
+
+   ret = __write_checkpoint_sync(sbi);
+   atomic_inc(&cprc->issued_ckpt);
+
+   llist_for_each_entry_safe(req, next, dispatch_list, llnode) {
+   atomic_dec(&cprc->queued_ckpt);
+   atomic_inc(&cprc->total_ckpt);
+   diff = (u64)ktime_ms_delta(ktime_get(), req->queue_time);
+

Re: [f2fs-dev] [PATCH 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

2021년 1월 11일 (월) 오후 6:34, Chao Yu 님이 작성:
>
> On 2021/1/11 13:15, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares, and The below verification result
> > explains this.
> > The basic idea has come from https://opensource.samsung.com.
>
> Nice proposal, we have the same idea for foreground GC, I guess we
> can upstream this later as well:
>
> https://consumer.huawei.com/en/opensource/
>
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> >"for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> > done"
> > - thread B => gererating async. I/O
> >"fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> > --filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> >"echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> > fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/  patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong 
> > Signed-off-by: Sungjong Seo 
> > ---
> >   Documentation/filesystems/f2fs.rst |   6 +
> >   fs/f2fs/checkpoint.c   | 176 +
> >   fs/f2fs/debug.c|   6 +
> >   fs/f2fs/f2fs.h |  24 
> >   fs/f2fs/super.c|  53 -
> >   5 files changed, 261 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..bccc021bf31a 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > +  Here is another option "merge", which creates a 
> > kernel daemon
> > +  and makes it to merge concurrent checkpoint requests 
> > as much
> > +  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +  we can eliminate the sluggish issue caused by slow 
> > checkpoint
> > +  operation when the checkpoint is done in a process 
> > context in
> > +  a cgroup having low i/o budget and cpu shares.
> >   compress_algorithm=%sControl compress algorithm, currently f2fs 
> > supports "lzo",
> >"lz4", "zstd" and "lzo-rle" algorithm.
> >   compress_log_size=%u Support configuring compress cluster size, 
> > the size will
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 897edb7c951a..11288f435dbe 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -13,6 +13,7 @@
> >   #include 
> >   #include 
> >   #include 
> > +#include 
> >
> >   #include "f2fs.h"
> >   #include "node.h"
> > @@ -20,6 +21,8 @@
> >   #include "trace.h"
> >   #include 
> >
> > +#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
> > +
> >   static struct kmem_cache *ino_entry_slab;
> >   struct kmem_cache *f2fs_inode_entry_slab;
> >
> > @@ -1707,3 +1710,176 @@ void f2fs_destroy_checkpoint_caches(void)
> >   kmem_cache_destroy(ino_entry_slab);
> >   kmem_cache_destroy(f2fs_inode_entry_slab);
> >   }
> > +
> > +stati

Re: [f2fs-dev] [PATCH 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

Got it~ :)

2021년 1월 11일 (월) 오후 6:50, Jaegeuk Kim 님이 작성:
>
> On 01/11, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We've added a new mount option "checkpoint=merge", which creates a
> > kernel daemon and makes it to merge concurrent checkpoint requests as
> > much as possible to eliminate redundant checkpoint issues. Plus, we
> > can eliminate the sluggish issue caused by slow checkpoint operation
> > when the checkpoint is done in a process context in a cgroup having
> > low i/o budget and cpu shares, and The below verification result
> > explains this.
> > The basic idea has come from https://opensource.samsung.com.
> >
> > [Verification]
> > Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
> > Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
> >
> > In "fg" cgroup,
> > - thread A => trigger 1000 checkpoint operations
> >   "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
> >done"
> > - thread B => gererating async. I/O
> >   "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
> >--filename=test_img --name=test"
> >
> > In "bg" cgroup,
> > - thread C => trigger repeated checkpoint operations
> >   "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
> >fsync test_dir2; done"
> >
> > We've measured thread A's execution time.
> >
> > [ w/o patch ]
> > Elapsed Time: Avg. 68 seconds
> > [ w/  patch ]
> > Elapsed Time: Avg. 48 seconds
> >
> > Signed-off-by: Daeho Jeong 
> > Signed-off-by: Sungjong Seo 
> > ---
> >  Documentation/filesystems/f2fs.rst |   6 +
> >  fs/f2fs/checkpoint.c   | 176 +
> >  fs/f2fs/debug.c|   6 +
> >  fs/f2fs/f2fs.h |  24 
> >  fs/f2fs/super.c|  53 -
> >  5 files changed, 261 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..bccc021bf31a 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off 
> > checkpointing. Set to "enabl
> >hide up to all remaining free space. The actual 
> > space that
> >would be unusable can be viewed at 
> > /sys/fs/f2fs//unusable
> >This space is reclaimed once checkpoint=enable.
> > +  Here is another option "merge", which creates a 
> > kernel daemon
> > +  and makes it to merge concurrent checkpoint requests 
> > as much
> > +  as possible to eliminate redundant checkpoint 
> > issues. Plus,
> > +  we can eliminate the sluggish issue caused by slow 
> > checkpoint
> > +  operation when the checkpoint is done in a process 
> > context in
> > +  a cgroup having low i/o budget and cpu shares.
> >  compress_algorithm=%s Control compress algorithm, currently f2fs 
> > supports "lzo",
> >"lz4", "zstd" and "lzo-rle" algorithm.
> >  compress_log_size=%u  Support configuring compress cluster size, the size 
> > will
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 897edb7c951a..11288f435dbe 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -13,6 +13,7 @@
> >  #include 
> >  #include 
> >  #include 
> > +#include 
> >
> >  #include "f2fs.h"
> >  #include "node.h"
> > @@ -20,6 +21,8 @@
> >  #include "trace.h"
> >  #include 
> >
> > +#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
> > +
> >  static struct kmem_cache *ino_entry_slab;
> >  struct kmem_cache *f2fs_inode_entry_slab;
> >
> > @@ -1707,3 +1710,176 @@ void f2fs_destroy_checkpoint_caches(void)
> >   kmem_cache_destroy(ino_entry_slab);
> >   kmem_cache_destroy(f2fs_inode_entry_slab);
> >  }
> > +
> > +static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
> > +{
> > + struct cp_control cpc = { .reason = CP_SYNC, };
> > + int err;
> > +
> > + down_write(&sbi->gc_l

[PATCH 1/2] f2fs: introduce checkpoint=merge mount option

[Daeho Jeong]

From: Daeho Jeong 

We've added a new mount option "checkpoint=merge", which creates a
kernel daemon and makes it to merge concurrent checkpoint requests as
much as possible to eliminate redundant checkpoint issues. Plus, we
can eliminate the sluggish issue caused by slow checkpoint operation
when the checkpoint is done in a process context in a cgroup having
low i/o budget and cpu shares, and The below verification result
explains this.
The basic idea has come from https://opensource.samsung.com.

[Verification]
Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)

In "fg" cgroup,
- thread A => trigger 1000 checkpoint operations
  "for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
   done"
- thread B => gererating async. I/O
  "fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
   --filename=test_img --name=test"

In "bg" cgroup,
- thread C => trigger repeated checkpoint operations
  "echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
   fsync test_dir2; done"

We've measured thread A's execution time.

[ w/o patch ]
Elapsed Time: Avg. 68 seconds
[ w/  patch ]
Elapsed Time: Avg. 48 seconds

Signed-off-by: Daeho Jeong 
Signed-off-by: Sungjong Seo 
---
 Documentation/filesystems/f2fs.rst |   6 +
 fs/f2fs/checkpoint.c   | 176 +
 fs/f2fs/debug.c|   6 +
 fs/f2fs/f2fs.h |  24 
 fs/f2fs/super.c|  53 -
 5 files changed, 261 insertions(+), 4 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index dae15c96e659..bccc021bf31a 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -247,6 +247,12 @@ checkpoint=%s[:%u[%]]   Set to "disable" to turn off 
checkpointing. Set to "enabl
 hide up to all remaining free space. The actual space 
that
 would be unusable can be viewed at 
/sys/fs/f2fs//unusable
 This space is reclaimed once checkpoint=enable.
+Here is another option "merge", which creates a kernel 
daemon
+and makes it to merge concurrent checkpoint requests 
as much
+as possible to eliminate redundant checkpoint issues. 
Plus,
+we can eliminate the sluggish issue caused by slow 
checkpoint
+operation when the checkpoint is done in a process 
context in
+a cgroup having low i/o budget and cpu shares.
 compress_algorithm=%s   Control compress algorithm, currently f2fs supports 
"lzo",
 "lz4", "zstd" and "lzo-rle" algorithm.
 compress_log_size=%uSupport configuring compress cluster size, the size 
will
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 897edb7c951a..11288f435dbe 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -13,6 +13,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "node.h"
@@ -20,6 +21,8 @@
 #include "trace.h"
 #include 
 
+#define DEFAULT_CHECKPOINT_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
+
 static struct kmem_cache *ino_entry_slab;
 struct kmem_cache *f2fs_inode_entry_slab;
 
@@ -1707,3 +1710,176 @@ void f2fs_destroy_checkpoint_caches(void)
kmem_cache_destroy(ino_entry_slab);
kmem_cache_destroy(f2fs_inode_entry_slab);
 }
+
+static int __write_checkpoint_sync(struct f2fs_sb_info *sbi)
+{
+   struct cp_control cpc = { .reason = CP_SYNC, };
+   int err;
+
+   down_write(&sbi->gc_lock);
+   err = f2fs_write_checkpoint(sbi, &cpc);
+   up_write(&sbi->gc_lock);
+
+   return err;
+}
+
+static void __checkpoint_and_complete_reqs(struct f2fs_sb_info *sbi)
+{
+   struct ckpt_req_control *cprc = sbi->cprc_info;
+   struct ckpt_req *req, *next;
+   struct llist_node *dispatch_list;
+   int ret;
+
+   dispatch_list = llist_del_all(&cprc->issue_list);
+   if (!dispatch_list)
+   return;
+   dispatch_list = llist_reverse_order(dispatch_list);
+
+   ret = __write_checkpoint_sync(sbi);
+   atomic_inc(&cprc->issued_ckpt);
+
+   llist_for_each_entry_safe(req, next, dispatch_list, llnode) {
+   atomic_dec(&cprc->queued_ckpt);
+   atomic_inc(&cprc->total_ckpt);
+   req->complete_time = jiffies;
+   req->ret = ret;
+   complete(&req->wait);
+   }
+}
+
+static int issue_checkpoint_thread(void *data)
+{
+   struct f2fs_sb_info *sbi = data;
+   struct ckpt_req_control *cprc = sbi->cprc_info;
+   wait_

[PATCH 2/2] f2fs: add ckpt_thread_ioprio sysfs node

[Daeho Jeong]

From: Daeho Jeong 

Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.

Signed-off-by: Daeho Jeong 
---
 Documentation/ABI/testing/sysfs-fs-f2fs |  8 
 fs/f2fs/checkpoint.c|  3 +-
 fs/f2fs/f2fs.h  |  1 +
 fs/f2fs/sysfs.c | 51 +
 4 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3dfee94e0618..0c48b2e7dfd4 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -377,3 +377,11 @@ Description:   This gives a control to limit the bio 
size in f2fs.
Default is zero, which will follow underlying block layer limit,
whereas, if it has a certain bytes value, f2fs won't submit a
bio larger than that size.
+What:  /sys/fs/f2fs//ckpt_thread_ioprio
+Date:  January 2021
+Contact:   "Daeho Jeong" 
+Description:   Give a way to change checkpoint merge daemon's io priority.
+   Its default value is "be,3", which means "BE" I/O class and
+   I/O priority "3". We can select the class between "rt" and "be",
+   and set the I/O priority within valid range of it. "," delimiter
+   is necessary in between I/O class and priority number.
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 11288f435dbe..37a393f97d5d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1839,6 +1839,7 @@ int f2fs_create_ckpt_req_control(struct f2fs_sb_info *sbi)
atomic_set(&cprc->issued_ckpt, 0);
atomic_set(&cprc->total_ckpt, 0);
atomic_set(&cprc->queued_ckpt, 0);
+   cprc->ckpt_thread_ioprio = DEFAULT_CHECKPOINT_IOPRIO;
init_waitqueue_head(&cprc->ckpt_wait_queue);
init_llist_head(&cprc->issue_list);
sbi->cprc_info = cprc;
@@ -1859,7 +1860,7 @@ int f2fs_create_ckpt_req_control(struct f2fs_sb_info *sbi)
return err;
}
 
-   set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
+   set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
 
return 0;
 }
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 4de5285df17d..957bf4c42d40 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -278,6 +278,7 @@ struct ckpt_req {
 
 struct ckpt_req_control {
struct task_struct *f2fs_issue_ckpt;/* checkpoint task */
+   int ckpt_thread_ioprio; /* checkpoint merge thread 
ioprio */
wait_queue_head_t ckpt_wait_queue;  /* waiting queue for wake-up */
atomic_t issued_ckpt;   /* # of actually issued ckpts */
atomic_t total_ckpt;/* # of total ckpts */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 30bae57428d1..295ebd84986b 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -11,6 +11,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "f2fs.h"
 #include "segment.h"
@@ -34,6 +35,7 @@ enum {
FAULT_INFO_TYPE,/* struct f2fs_fault_info */
 #endif
RESERVED_BLOCKS,/* struct f2fs_sb_info */
+   CPRC_INFO,  /* struct ckpt_req_control */
 };
 
 struct f2fs_attr {
@@ -70,6 +72,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, 
int struct_type)
else if (struct_type == STAT_INFO)
return (unsigned char *)F2FS_STAT(sbi);
 #endif
+   else if (struct_type == CPRC_INFO)
+   return (unsigned char *)sbi->cprc_info;
return NULL;
 }
 
@@ -255,6 +259,23 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
return len;
}
 
+   if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+   struct ckpt_req_control *cprc = sbi->cprc_info;
+   int len = 0;
+   int class = IOPRIO_PRIO_CLASS(cprc->ckpt_thread_ioprio);
+   int data = IOPRIO_PRIO_DATA(cprc->ckpt_thread_ioprio);
+
+   if (class == IOPRIO_CLASS_RT)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "rt,");
+   else if (class == IOPRIO_CLASS_BE)
+   len += scnprintf(buf + len, PAGE_SIZE - len, "be,");
+   else
+   return -EINVAL;
+
+   len += scnprintf(buf + len, PAGE_SIZE - len, "%d\n", data);
+  

Re: [f2fs-dev] [PATCH v2] f2fs: fix null page reference in redirty_blocks

[Daeho Jeong]

Thanks for the notice~

2021년 1월 6일 (수) 오전 10:04, Chao Yu 님이 작성:
>
> Daeho,
>
> FYI
>
> https://www.spinics.net/lists/kernel/msg3595944.html
>
> On 2021/1/5 20:04, Markus Elfring wrote:
> >> Fixed null page reference when find_lock_page() fails in
> >> redirty_blocks().
> >
> > I suggest to choose an other imperative wording for this change description.
> >
> > See also:
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=36bbbd0e234d817938bdc52121a0f5473b3e58f5#n89
> >
> >
> >> v2: changed error value and break the loop when error occurs
> >
> > I propose to use a return statement instead of a break in the second if 
> > branch
> > for this function implementation.
> >
> > See also:
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=36bbbd0e234d817938bdc52121a0f5473b3e58f5#n481
> >
> > Regards,
> > Markus
> >
> >
> > ___
> > Linux-f2fs-devel mailing list
> > linux-f2fs-de...@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > .
> >
>
>
> ___
> Linux-f2fs-devel mailing list
> linux-f2fs-de...@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

[PATCH v2] f2fs: fix null page reference in redirty_blocks

[Daeho Jeong]

From: Daeho Jeong 

By Colin's static analysis, we found out there is a null page reference
under low memory situation in redirty_blocks. I've made the page finding
loop stop immediately and return an error not to cause further memory
pressure when we run into a failure to find a page under low memory
condition.

Signed-off-by: Daeho Jeong 
Reported-by: Colin Ian King 
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and 
F2FS_IOC_COMPRESS_FILE")
---
v2: changed error value and quit the page finding loop immediately
when error occurs
---
 fs/f2fs/file.c | 6 --
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..d27173c24391 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t 
page_idx, int len)
 
for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
-   if (!page)
-   ret = -ENOENT;
+   if (!page) {
+   ret = -ENOMEM;
+   break;
+   }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
-- 
2.29.2.729.g45daf8777d-goog

Re: [f2fs-dev] [PATCH v2] f2fs: fix null page reference in redirty_blocks

[Daeho Jeong]

Got it~

Thanks,

2021년 1월 5일 (화) 오후 9:06, Markus Elfring 님이 작성:
>
> > Fixed null page reference when find_lock_page() fails in
> > redirty_blocks().
>
> I suggest to choose an other imperative wording for this change description.
>
> See also:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=36bbbd0e234d817938bdc52121a0f5473b3e58f5#n89
>
>
> > v2: changed error value and break the loop when error occurs
>
> I propose to use a return statement instead of a break in the second if branch
> for this function implementation.
>
> See also:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=36bbbd0e234d817938bdc52121a0f5473b3e58f5#n481
>
> Regards,
> Markus
>
>
> ___
> Linux-f2fs-devel mailing list
> linux-f2fs-de...@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

[PATCH v2] f2fs: fix null page reference in redirty_blocks

[Daeho Jeong]

From: Daeho Jeong 

Fixed null page reference when find_lock_page() fails in
redirty_blocks().

Signed-off-by: Daeho Jeong 
Reported-by: Colin Ian King 
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and 
F2FS_IOC_COMPRESS_FILE")
---
v2: changed error value and break the loop when error occurs
---
 fs/f2fs/file.c | 6 --
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..d27173c24391 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t 
page_idx, int len)
 
for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
-   if (!page)
-   ret = -ENOENT;
+   if (!page) {
+   ret = -ENOMEM;
+   break;
+   }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
-- 
2.29.2.729.g45daf8777d-goog

Re: [f2fs-dev] [PATCH] f2fs: fix null page reference in redirty_blocks

[Daeho Jeong]

Yes, it's better~ :)

2021년 1월 5일 (화) 오전 10:44, Chao Yu 님이 작성:
>
> On 2021/1/5 9:28, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Fixed null page reference when find_lock_page() fails in
> > redirty_blocks().
> >
> > Signed-off-by: Daeho Jeong 
> > Reported-by: Colin Ian King 
> > Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and 
> > F2FS_IOC_COMPRESS_FILE")
> > ---
> >   fs/f2fs/file.c | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 9e5275716be8..bf6682a52433 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, 
> > pgoff_t page_idx, int len)
> >
> >   for (i = 0; i < page_len; i++, redirty_idx++) {
> >   page = find_lock_page(mapping, redirty_idx);
> > - if (!page)
> > + if (!page) {
> >   ret = -ENOENT;
>
> ret = -ENOMEM;
>
> > + continue;
>
> How about breaking the loop for out-of-memory case, because in such condition
> we have less chance to dirty whole cluster due to no memory, and continue to
> allocate pages for target file will make system suffer more memory pressure,
> it will make many thing slower.
>
> Thnaks,
>
> > + }
> >   set_page_dirty(page);
> >   f2fs_put_page(page, 1);
> >   f2fs_put_page(page, 0);
> >

[PATCH] f2fs: fix null page reference in redirty_blocks

[Daeho Jeong]

From: Daeho Jeong 

Fixed null page reference when find_lock_page() fails in
redirty_blocks().

Signed-off-by: Daeho Jeong 
Reported-by: Colin Ian King 
Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and 
F2FS_IOC_COMPRESS_FILE")
---
 fs/f2fs/file.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9e5275716be8..bf6682a52433 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t 
page_idx, int len)
 
for (i = 0; i < page_len; i++, redirty_idx++) {
page = find_lock_page(mapping, redirty_idx);
-   if (!page)
+   if (!page) {
ret = -ENOENT;
+   continue;
+   }
set_page_dirty(page);
f2fs_put_page(page, 1);
f2fs_put_page(page, 0);
-- 
2.29.2.729.g45daf8777d-goog

Re: [f2fs-dev] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

Hi Colin,

Thanks for notifying me. We need to just continue without
set_page_dirty() and f2fs_put_page().

2021년 1월 4일 (월) 오후 11:43, Colin Ian King 님이 작성:
>
> Hi,
>
> Static analysis using Coverity has detected a potential null pointer
> dereference after a null check in the following commit:
>
> commit 5fdb322ff2c2b4ad519f490dcb7ebb96c5439af7
> Author: Daeho Jeong 
> Date:   Thu Dec 3 15:56:15 2020 +0900
>
> f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE
>
> The analysis is as follows:
>
> 4025 static int redirty_blocks(struct inode *inode, pgoff_t page_idx,
> int len)
> 4026 {
> 4027DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
> 4028struct address_space *mapping = inode->i_mapping;
> 4029struct page *page;
> 4030pgoff_t redirty_idx = page_idx;
> 4031int i, page_len = 0, ret = 0;
> 4032
> 4033page_cache_ra_unbounded(&ractl, len, 0);
> 4034
>
> 1. Condition i < len, taking true branch.
> 4. Condition i < len, taking true branch.
>
> 4035for (i = 0; i < len; i++, page_idx++) {
> 4036page = read_cache_page(mapping, page_idx, NULL, NULL);
>
> 2. Condition IS_ERR(page), taking false branch.
> 5. Condition IS_ERR(page), taking true branch.
>
> 4037if (IS_ERR(page)) {
> 4038ret = PTR_ERR(page);
>
> 6. Breaking from loop.
>
> 4039break;
> 4040}
> 4041page_len++;
>
> 3. Jumping back to the beginning of the loop.
>
> 4042}
> 4043
>
> 7. Condition i < page_len, taking true branch.
>
> 4044for (i = 0; i < page_len; i++, redirty_idx++) {
> 4045page = find_lock_page(mapping, redirty_idx);
>
> 8. Condition !page, taking true branch.
> 9. var_compare_op: Comparing page to null implies that page might be
> null.
>
> 4046if (!page)
> 4047ret = -ENOENT;
>
> Dereference after null check (FORWARD_NULL)
>
>10. var_deref_model: Passing null pointer page to set_page_dirty,
> which dereferences it.
>
> 4048set_page_dirty(page);
> 4049f2fs_put_page(page, 1);
> 4050f2fs_put_page(page, 0);
> 4051}
> 4052
> 4053return ret;
> 4054 }
>
> The !page check on line 4046 sets ret appropriately but we have a
> following call to set_page_dirty on a null page that causes the error.
> Not sure how this should be fixed, should the check bail out immediately
> or just avoid the following set_page_dirty anf f2fs_put_page calls?
>
> Colin
>
>
>
> ___
> Linux-f2fs-devel mailing list
> linux-f2fs-de...@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [PATCH v2 1/2] f2fs: add compress_mode mount option

[Daeho Jeong]

compression enabled regular files have different formats of node
metadata on disk. So, using the
"compress_mode=user,compress_extension=*" mount option, we want to
make the metadata of files ready for compression and make them
compressed whenever the user wants using new ioctls.

2020년 12월 8일 (화) 오후 12:51, Eric Biggers 님이 작성:
>
> On Tue, Dec 01, 2020 at 01:08:02PM +0900, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We will add a new "compress_mode" mount option to control file
> > compression mode. This supports "fs" and "user". In "fs" mode (default),
> > f2fs does automatic compression on the compression enabled files.
> > In "user" mode, f2fs disables the automaic compression and gives the
> > user discretion of choosing the target file and the timing. It means
> > the user can do manual compression/decompression on the compression
> > enabled files using ioctls.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> > v2: changed mount option name and added more explanation of mount option
> > ---
> >  Documentation/filesystems/f2fs.rst | 35 ++
> >  fs/f2fs/compress.c |  2 +-
> >  fs/f2fs/data.c |  2 +-
> >  fs/f2fs/f2fs.h | 30 +
> >  fs/f2fs/segment.c  |  2 +-
> >  fs/f2fs/super.c| 23 
> >  6 files changed, 91 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index b8ee761c9922..5eb8d63439ec 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -260,6 +260,13 @@ compress_extension=%s Support adding specified 
> > extension, so that f2fs can enab
> >For other files, we can still enable compression via 
> > ioctl.
> >Note that, there is one reserved special extension 
> > '*', it
> >can be set to enable compression for all files.
> > +compress_mode=%s  Control file compression mode. This supports "fs" 
> > and "user"
> > +  modes. In "fs" mode (default), f2fs does automatic 
> > compression
> > +  on the compression enabled files. In "user" mode, 
> > f2fs disables
> > +  the automaic compression and gives the user 
> > discretion of
> > +  choosing the target file and the timing. The user 
> > can do manual
> > +  compression/decompression on the compression enabled 
> > files using
> > +  ioctls.
> >  inlinecrypt   When possible, encrypt/decrypt the contents of 
> > encrypted
> >files using the blk-crypto framework rather than
> >filesystem-layer encryption. This allows the use of
> > @@ -810,6 +817,34 @@ Compress metadata layout::
> >   | data length | data chksum | reserved |  compressed data   |
> >   +-+-+--++
> >
> > +Compression mode
> > +--
> > +
> > +f2fs supports "fs" and "user" compression modes with "compression_mode" 
> > mount option.
> > +With this option, f2fs provides a choice to select the way how to compress 
> > the
> > +compression enabled files (refer to "Compression implementation" section 
> > for how to
> > +enable compression on a regular inode).
> > +
> > +1) compress_mode=fs
> > +This is the default option. f2fs does automatic compression in the 
> > writeback of the
> > +compression enabled files.
> > +
> > +2) compress_mode=user
> > +This disables the automaic compression and gives the user discretion of 
> > choosing the
> > +target file and the timing. The user can do manual 
> > compression/decompression on the
> > +compression enabled files using F2FS_IOC_DECOMPRESS_FILE and 
> > F2FS_IOC_COMPRESS_FILE
> > +ioctls like the below.
> > +
> > +To decompress a file,
> > +
> > +fd = open(filename, O_WRONLY, 0);
> > +ret = ioctl(fd, F2FS_IOC_DECOMPRESS_FILE);
> > +
> > +To compress a file,
> > +
> > +fd = open(filename, O_WRONLY, 0);
> > +ret = ioctl(fd, F2FS_IOC_COMPRESS_FILE);
> > +
>
> Why doesn't compress_mode=user just cause regular files to not inherit the
> compression flag?  Then users could set or clear the compression flag using
> FS_IOC_SETFLAGS, without any need for these new ioctls.
>
> - Eric

Re: [f2fs-dev] [PATCH v3] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

Chao, Jaegeuk,

Thanks. I'll update it as your comments. :)

Eric,

Decompression and verity can be executed in different thread contexts
in different timing, so we need separate counts for each.

We already use STEP_VERITY for non-compression case, so I think using
this flag in here looks more making sense.

Thanks,

2020년 12월 8일 (화) 오전 5:31, Eric Biggers 님이 작성:
>
> On Sat, Dec 05, 2020 at 01:26:26PM +0900, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > I found out f2fs_free_dic() is invoked in a wrong timing, but
> > f2fs_verify_bio() still needed the dic info and it triggered the
> > below kernel panic. It has been caused by the race condition of
> > pending_pages value between decompression and verity logic, when
> > the same compression cluster had been split in different bios.
> > By split bios, f2fs_verify_bio() ended up with decreasing
> > pending_pages value before it is reset to nr_cpages by
> > f2fs_decompress_pages() and caused the kernel panic.
> >
> > [ 4416.564763] Unable to handle kernel NULL pointer dereference
> >at virtual address 
> > ...
> > [ 4416.896016] Workqueue: fsverity_read_queue f2fs_verity_work
> > [ 4416.908515] pc : fsverity_verify_page+0x20/0x78
> > [ 4416.913721] lr : f2fs_verify_bio+0x11c/0x29c
> > [ 4416.913722] sp : ffc019533cd0
> > [ 4416.913723] x29: ffc019533cd0 x28: 0402
> > [ 4416.913724] x27: 0001 x26: 0100
> > [ 4416.913726] x25: 0001 x24: 0004
> > [ 4416.913727] x23: 1000 x22: 
> > [ 4416.913728] x21:  x20: 2076f9c0
> > [ 4416.913729] x19: 2076f9c0 x18: ff8a32380c30
> > [ 4416.913731] x17: ffc01f966d97 x16: 0298
> > [ 4416.913732] x15:  x14: 
> > [ 4416.913733] x13: f074faec89ff x12: 
> > [ 4416.913734] x11: 1000 x10: 1000
> > [ 4416.929176] x9 : 20d1f5c7 x8 : 
> > [ 4416.929178] x7 : 626d7464ff286b6b x6 : ffc019533ade
> > [ 4416.929179] x5 : 8049000e x4 : 2793e9e0
> > [ 4416.929180] x3 : 8049000e x2 : ff89ecfa74d0
> > [ 4416.929181] x1 : 0c40 x0 : 2076f9c0
> > [ 4416.929184] Call trace:
> > [ 4416.929187]  fsverity_verify_page+0x20/0x78
> > [ 4416.929189]  f2fs_verify_bio+0x11c/0x29c
> > [ 4416.929192]  f2fs_verity_work+0x58/0x84
> > [ 4417.050667]  process_one_work+0x270/0x47c
> > [ 4417.055354]  worker_thread+0x27c/0x4d8
> > [ 4417.059784]  kthread+0x13c/0x320
> > [ 4417.063693]  ret_from_fork+0x10/0x18
> >
> > Signed-off-by: Daeho Jeong 
> > Signed-off-by: Jaegeuk Kim 
> > ---
> > v3: back to v1 and enabled verity in a unit of cluster
> > v2: merged verity_pages with pending_pages, and increased the
> > pending_pages count only if STEP_VERITY is set on bio
>
> I am trying to review this but it is very hard, as the f2fs compression code 
> is
> very hard to understand.
>
> It looks like a 'struct decompress_io_ctx' represents the work to decompress a
> particular cluster.  Since the compressed data of the cluster can be read 
> using
> multiple bios, there is a reference count of how many pages are remaining to 
> be
> read before all the cluster's pages have been read and decompression can 
> start.
>
> What I don't understand is why that reference counting needs to work 
> differently
> depending on whether verity is enabled or not.  Shouldn't it be exactly the
> same?
>
> There also seems to be some confusion about the scope of STEP_VERITY.  Before
> f2fs compression was added, it was a per-bio thing.  But now in a compressed
> file, it's really a per-cluster thing, since all decompressed pages in a
> compressed cluster are verified (or not verified) at once.
>
> Wouldn't it make a lot more sense to, when a cluster needs both compression 
> and
> verity, *not* set STEP_VERITY on the bios, but rather set a similar flag in 
> the
> decompress_io_ctx?
>
> - Eric

Re: [f2fs-dev] [PATCH v3] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

> It looks like it will be better to move this into merge condition?
>
> if (bio && (!page_is_mergeable(sbi, bio,
> *last_block_in_bio, blkaddr) ||
> !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL) 
> ||
> f2fs_verify_mergeable_bio())) {
>

I tried this for the first time, but it requires unnecessary checks
within the compression cluster.
I wanted to just check one time in the beginning of the cluster.
What do you think?

[PATCH v3] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

From: Daeho Jeong 

I found out f2fs_free_dic() is invoked in a wrong timing, but
f2fs_verify_bio() still needed the dic info and it triggered the
below kernel panic. It has been caused by the race condition of
pending_pages value between decompression and verity logic, when
the same compression cluster had been split in different bios.
By split bios, f2fs_verify_bio() ended up with decreasing
pending_pages value before it is reset to nr_cpages by
f2fs_decompress_pages() and caused the kernel panic.

[ 4416.564763] Unable to handle kernel NULL pointer dereference
   at virtual address 
...
[ 4416.896016] Workqueue: fsverity_read_queue f2fs_verity_work
[ 4416.908515] pc : fsverity_verify_page+0x20/0x78
[ 4416.913721] lr : f2fs_verify_bio+0x11c/0x29c
[ 4416.913722] sp : ffc019533cd0
[ 4416.913723] x29: ffc019533cd0 x28: 0402
[ 4416.913724] x27: 0001 x26: 0100
[ 4416.913726] x25: 0001 x24: 0004
[ 4416.913727] x23: 1000 x22: 
[ 4416.913728] x21:  x20: 2076f9c0
[ 4416.913729] x19: 2076f9c0 x18: ff8a32380c30
[ 4416.913731] x17: ffc01f966d97 x16: 0298
[ 4416.913732] x15:  x14: 
[ 4416.913733] x13: f074faec89ff x12: 
[ 4416.913734] x11: 1000 x10: 1000
[ 4416.929176] x9 : 20d1f5c7 x8 : 
[ 4416.929178] x7 : 626d7464ff286b6b x6 : ffc019533ade
[ 4416.929179] x5 : 8049000e x4 : 2793e9e0
[ 4416.929180] x3 : 8049000e x2 : ff89ecfa74d0
[ 4416.929181] x1 : 0c40 x0 : 2076f9c0
[ 4416.929184] Call trace:
[ 4416.929187]  fsverity_verify_page+0x20/0x78
[ 4416.929189]  f2fs_verify_bio+0x11c/0x29c
[ 4416.929192]  f2fs_verity_work+0x58/0x84
[ 4417.050667]  process_one_work+0x270/0x47c
[ 4417.055354]  worker_thread+0x27c/0x4d8
[ 4417.059784]  kthread+0x13c/0x320
[ 4417.063693]  ret_from_fork+0x10/0x18

Signed-off-by: Daeho Jeong 
Signed-off-by: Jaegeuk Kim 
---
v3: back to v1 and enabled verity in a unit of cluster
v2: merged verity_pages with pending_pages, and increased the
pending_pages count only if STEP_VERITY is set on bio
---
 fs/f2fs/compress.c |  2 --
 fs/f2fs/data.c | 51 --
 fs/f2fs/f2fs.h |  1 +
 3 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 87090da8693d..832b19986caf 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -803,8 +803,6 @@ void f2fs_decompress_pages(struct bio *bio, struct page 
*page, bool verity)
if (cops->destroy_decompress_ctx)
cops->destroy_decompress_ctx(dic);
 out_free_dic:
-   if (verity)
-   atomic_set(&dic->pending_pages, dic->nr_cpages);
if (!verity)
f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
ret, false);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 42254d3859c7..861e5783a5fc 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -202,7 +202,7 @@ static void f2fs_verify_bio(struct bio *bio)
dic = (struct decompress_io_ctx *)page_private(page);
 
if (dic) {
-   if (atomic_dec_return(&dic->pending_pages))
+   if (atomic_dec_return(&dic->verity_pages))
continue;
f2fs_verify_pages(dic->rpages,
dic->cluster_size);
@@ -1027,7 +1027,8 @@ static inline bool f2fs_need_verity(const struct inode 
*inode, pgoff_t idx)
 
 static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
  unsigned nr_pages, unsigned op_flag,
- pgoff_t first_idx, bool for_write)
+ pgoff_t first_idx, bool for_write,
+ bool for_verity)
 {
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct bio *bio;
@@ -1049,7 +1050,7 @@ static struct bio *f2fs_grab_read_bio(struct inode 
*inode, block_t blkaddr,
post_read_steps |= 1 << STEP_DECRYPT;
if (f2fs_compressed_file(inode))
post_read_steps |= 1 << STEP_DECOMPRESS_NOWQ;
-   if (f2fs_need_verity(inode, first_idx))
+   if (for_verity && f2fs_need_verity(inode, first_idx))
post_read_steps |= 1 << STEP_VERITY;
 
if (post_read_steps) {
@@ -1079,7 +1080,7 @@ static int f2fs_submit_page_read(struct inode *inode, 
struct page *page,
struct bio *bio;
 
bio = f2fs_grab_read_bio(inode, blkaddr, 1, op_flags,
-   page->index, for_write);
+ 

Re: [f2fs-dev] [PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

Yep, we need to come back to v1 and enable verity in a unit of cluster.
Plus, as I told you, I'll prevent newly verity enalbed pages from
being merged with verity disabled bio.

Thanks,

2020년 12월 5일 (토) 오전 3:29, Jaegeuk Kim 님이 작성:
>
> On 12/04, Daeho Jeong wrote:
> > Thanks for the explanation about verity.
> > I got your point. Thanks~
>
> Possible fix can be like this?
>
> ---
>  fs/f2fs/compress.c |  2 --
>  fs/f2fs/data.c | 19 +--
>  2 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> index 89f73a7c8667..c5fee4d7ea72 100644
> --- a/fs/f2fs/compress.c
> +++ b/fs/f2fs/compress.c
> @@ -1491,8 +1491,6 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct 
> compress_ctx *cc)
> dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
> dic->inode = cc->inode;
> atomic_set(&dic->pending_pages, cc->nr_cpages);
> -   if (fsverity_active(cc->inode))
> -   atomic_set(&dic->verity_pages, cc->nr_cpages);
> dic->cluster_idx = cc->cluster_idx;
> dic->cluster_size = cc->cluster_size;
> dic->log_cluster_size = cc->log_cluster_size;
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index e3168f32f943..657fb562d7d4 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1035,7 +1035,8 @@ static inline bool f2fs_need_verity(const struct inode 
> *inode, pgoff_t idx)
>
>  static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
>   unsigned nr_pages, unsigned op_flag,
> - pgoff_t first_idx, bool for_write)
> + pgoff_t first_idx, bool for_write,
> + bool for_verity)
>  {
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> struct bio *bio;
> @@ -1057,7 +1058,7 @@ static struct bio *f2fs_grab_read_bio(struct inode 
> *inode, block_t blkaddr,
> post_read_steps |= 1 << STEP_DECRYPT;
> if (f2fs_compressed_file(inode))
> post_read_steps |= 1 << STEP_DECOMPRESS_NOWQ;
> -   if (f2fs_need_verity(inode, first_idx))
> +   if (for_verity && f2fs_need_verity(inode, first_idx))
> post_read_steps |= 1 << STEP_VERITY;
>
> if (post_read_steps) {
> @@ -1087,7 +1088,7 @@ static int f2fs_submit_page_read(struct inode *inode, 
> struct page *page,
> struct bio *bio;
>
> bio = f2fs_grab_read_bio(inode, blkaddr, 1, op_flags,
> -   page->index, for_write);
> +   page->index, for_write, true);
> if (IS_ERR(bio))
> return PTR_ERR(bio);
>
> @@ -2141,7 +2142,7 @@ static int f2fs_read_single_page(struct inode *inode, 
> struct page *page,
> if (bio == NULL) {
> bio = f2fs_grab_read_bio(inode, block_nr, nr_pages,
> is_readahead ? REQ_RAHEAD : 0, page->index,
> -   false);
> +   false, true);
> if (IS_ERR(bio)) {
> ret = PTR_ERR(bio);
> bio = NULL;
> @@ -2188,6 +2189,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, 
> struct bio **bio_ret,
> const unsigned blkbits = inode->i_blkbits;
> const unsigned blocksize = 1 << blkbits;
> struct decompress_io_ctx *dic = NULL;
> +   bool for_verity = false;
> int i;
> int ret = 0;
>
> @@ -2253,6 +2255,11 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, 
> struct bio **bio_ret,
> goto out_put_dnode;
> }
>
> +   if (fsverity_active(cc->inode)) {
> +   atomic_set(&dic->verity_pages, cc->nr_cpages);
> +   for_verity = true;
> +   }
> +
> for (i = 0; i < dic->nr_cpages; i++) {
> struct page *page = dic->cpages[i];
> block_t blkaddr;
> @@ -2272,7 +2279,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, 
> struct bio **bio_ret,
> if (!bio) {
> bio = f2fs_grab_read_bio(inode, blkaddr, nr_pages,
> is_readahead ? REQ_RAHEAD : 0,
> -   page->index, for_write);
> +   page->index, for_write, for_verity);
> if (IS_ERR(bio)) {
> unsigned int remained = dic->nr_cpages - i;
> 

Re: [f2fs-dev] [PATCH v2] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

As I told, this patch has a bug. Ignore this one. So, I'm implementing
another one. :(

2020년 12월 4일 (금) 오후 6:50, Daeho Jeong 님이 작성:
>
> As I told, this patch has a bug. Ignore this one. So, I'm implementing 
> another one. :(
>
>
> 2020년 12월 4일 (금) 오후 5:04, Chao Yu 님이 작성:
>>
>> On 2020/12/4 15:28, Daeho Jeong wrote:
>> > From: Daeho Jeong 
>> >
>> > I found out f2fs_free_dic() is invoked in a wrong timing, but
>> > f2fs_verify_bio() still needed the dic info and it triggered the
>> > below kernel panic. It has been caused by the race condition of
>> > pending_pages value between decompression and verity logic, when
>> > the same compression cluster had been split in different bios.
>> > By split bios, f2fs_verify_bio() ended up with decreasing
>> > pending_pages value before it is reset to nr_cpages by
>> > f2fs_decompress_pages() and caused the kernel panic.
>> >
>> > [ 4416.564763] Unable to handle kernel NULL pointer dereference
>> > at virtual address 
>> > ...
>> > [ 4416.896016] Workqueue: fsverity_read_queue f2fs_verity_work
>> > [ 4416.908515] pc : fsverity_verify_page+0x20/0x78
>> > [ 4416.913721] lr : f2fs_verify_bio+0x11c/0x29c
>> > [ 4416.913722] sp : ffc019533cd0
>> > [ 4416.913723] x29: ffc019533cd0 x28: 0402
>> > [ 4416.913724] x27: 0001 x26: 0100
>> > [ 4416.913726] x25: 0001 x24: 0004
>> > [ 4416.913727] x23: 1000 x22: 
>> > [ 4416.913728] x21:  x20: 2076f9c0
>> > [ 4416.913729] x19: 2076f9c0 x18: ff8a32380c30
>> > [ 4416.913731] x17: ffc01f966d97 x16: 0298
>> > [ 4416.913732] x15:  x14: 
>> > [ 4416.913733] x13: f074faec89ff x12: 
>> > [ 4416.913734] x11: 1000 x10: 1000
>> > [ 4416.929176] x9 : 20d1f5c7 x8 : 
>> > [ 4416.929178] x7 : 626d7464ff286b6b x6 : ffc019533ade
>> > [ 4416.929179] x5 : 8049000e x4 : 2793e9e0
>> > [ 4416.929180] x3 : 8049000e x2 : ff89ecfa74d0
>> > [ 4416.929181] x1 : 0c40 x0 : 2076f9c0
>> > [ 4416.929184] Call trace:
>> > [ 4416.929187]  fsverity_verify_page+0x20/0x78
>> > [ 4416.929189]  f2fs_verify_bio+0x11c/0x29c
>> > [ 4416.929192]  f2fs_verity_work+0x58/0x84
>> > [ 4417.050667]  process_one_work+0x270/0x47c
>> > [ 4417.055354]  worker_thread+0x27c/0x4d8
>> > [ 4417.059784]  kthread+0x13c/0x320
>> > [ 4417.063693]  ret_from_fork+0x10/0x18
>> >
>> > Signed-off-by: Daeho Jeong 
>> > Signed-off-by: Jaegeuk Kim 
>> > ---
>> > v2: merged verity_pages with pending_pages, and increased the
>> >  pending_pages count only if STEP_VERITY is set on bio
>> > ---
>> >   fs/f2fs/compress.c | 2 --
>> >   fs/f2fs/data.c | 2 ++
>> >   fs/f2fs/f2fs.h | 2 +-
>> >   3 files changed, 3 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
>> > index 87090da8693d..832b19986caf 100644
>> > --- a/fs/f2fs/compress.c
>> > +++ b/fs/f2fs/compress.c
>> > @@ -803,8 +803,6 @@ void f2fs_decompress_pages(struct bio *bio, struct 
>> > page *page, bool verity)
>> >   if (cops->destroy_decompress_ctx)
>> >   cops->destroy_decompress_ctx(dic);
>> >   out_free_dic:
>> > - if (verity)
>> > - atomic_set(&dic->pending_pages, dic->nr_cpages);
>> >   if (!verity)
>> >   f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
>> >   ret, false);
>> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> > index 42254d3859c7..b825d63cabdd 100644
>> > --- a/fs/f2fs/data.c
>> > +++ b/fs/f2fs/data.c
>> > @@ -2290,6 +2290,8 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, 
>> > struct bio **bio_ret,
>> >   ctx = bio->bi_private;
>> >   if (!(ctx->enabled_steps & (1 << STEP_DECOMPRESS)))
>> >   ctx->enabled_steps |= 1 << STEP_DECOMPRESS;
>> > + if (ctx->enabled_steps & (1 << STEP_VERITY))
>> > + atomic_inc(&dic->pending_pages);
>>
>> Hmm

[PATCH v2] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

From: Daeho Jeong 

I found out f2fs_free_dic() is invoked in a wrong timing, but
f2fs_verify_bio() still needed the dic info and it triggered the
below kernel panic. It has been caused by the race condition of
pending_pages value between decompression and verity logic, when
the same compression cluster had been split in different bios.
By split bios, f2fs_verify_bio() ended up with decreasing
pending_pages value before it is reset to nr_cpages by
f2fs_decompress_pages() and caused the kernel panic.

[ 4416.564763] Unable to handle kernel NULL pointer dereference
   at virtual address 
...
[ 4416.896016] Workqueue: fsverity_read_queue f2fs_verity_work
[ 4416.908515] pc : fsverity_verify_page+0x20/0x78
[ 4416.913721] lr : f2fs_verify_bio+0x11c/0x29c
[ 4416.913722] sp : ffc019533cd0
[ 4416.913723] x29: ffc019533cd0 x28: 0402
[ 4416.913724] x27: 0001 x26: 0100
[ 4416.913726] x25: 0001 x24: 0004
[ 4416.913727] x23: 1000 x22: 
[ 4416.913728] x21:  x20: 2076f9c0
[ 4416.913729] x19: 2076f9c0 x18: ff8a32380c30
[ 4416.913731] x17: ffc01f966d97 x16: 0298
[ 4416.913732] x15:  x14: 
[ 4416.913733] x13: f074faec89ff x12: 
[ 4416.913734] x11: 1000 x10: 1000
[ 4416.929176] x9 : 20d1f5c7 x8 : 
[ 4416.929178] x7 : 626d7464ff286b6b x6 : ffc019533ade
[ 4416.929179] x5 : 8049000e x4 : 2793e9e0
[ 4416.929180] x3 : 8049000e x2 : ff89ecfa74d0
[ 4416.929181] x1 : 0c40 x0 : 2076f9c0
[ 4416.929184] Call trace:
[ 4416.929187]  fsverity_verify_page+0x20/0x78
[ 4416.929189]  f2fs_verify_bio+0x11c/0x29c
[ 4416.929192]  f2fs_verity_work+0x58/0x84
[ 4417.050667]  process_one_work+0x270/0x47c
[ 4417.055354]  worker_thread+0x27c/0x4d8
[ 4417.059784]  kthread+0x13c/0x320
[ 4417.063693]  ret_from_fork+0x10/0x18

Signed-off-by: Daeho Jeong 
Signed-off-by: Jaegeuk Kim 
---
v2: merged verity_pages with pending_pages, and increased the
pending_pages count only if STEP_VERITY is set on bio
---
 fs/f2fs/compress.c | 2 --
 fs/f2fs/data.c | 2 ++
 fs/f2fs/f2fs.h | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 87090da8693d..832b19986caf 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -803,8 +803,6 @@ void f2fs_decompress_pages(struct bio *bio, struct page 
*page, bool verity)
if (cops->destroy_decompress_ctx)
cops->destroy_decompress_ctx(dic);
 out_free_dic:
-   if (verity)
-   atomic_set(&dic->pending_pages, dic->nr_cpages);
if (!verity)
f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
ret, false);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 42254d3859c7..b825d63cabdd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2290,6 +2290,8 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct 
bio **bio_ret,
ctx = bio->bi_private;
if (!(ctx->enabled_steps & (1 << STEP_DECOMPRESS)))
ctx->enabled_steps |= 1 << STEP_DECOMPRESS;
+   if (ctx->enabled_steps & (1 << STEP_VERITY))
+   atomic_inc(&dic->pending_pages);
 
inc_page_count(sbi, F2FS_RD_DATA);
f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 94d16bde5e24..a9ee7921c7ec 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1340,7 +1340,7 @@ struct decompress_io_ctx {
struct compress_data *cbuf; /* virtual mapped address on cpages */
size_t rlen;/* valid data length in rbuf */
size_t clen;/* valid data length in cbuf */
-   atomic_t pending_pages; /* in-flight compressed page count */
+   atomic_t pending_pages; /* in-flight compressed + verity page 
count */
bool failed;/* indicate IO error during 
decompression */
void *private;  /* payload buffer for specified 
decompression algorithm */
void *private2; /* extra payload buffer */
-- 
2.29.2.576.ga3fc446d84-goog

Re: [f2fs-dev] [PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

Thanks for the explanation about verity.
I got your point. Thanks~

2020년 12월 4일 (금) 오후 2:18, Eric Biggers 님이 작성:
>
> On Fri, Dec 04, 2020 at 02:00:34PM +0900, Daeho Jeong wrote:
> > I think I don't understand how verity works.
> > Right after verity is enabled on a file, is the verity logic working
> > for the whole file data area?
> > Or it's just working for the data area which is updated after verity is 
> > enabled?
> >
>
> It's for the whole file.
>
> My point is just that if there is a bio that saw that verity isn't enabled yet
> when it started and therefore STEP_VERITY didn't get set in the
> bio_post_read_ctx (or the bio_post_read_ctx didn't get allocated due to one 
> not
> being needed), then the filesystem shouldn't change its mind and try to verify
> the pages when the bio completes if verity happened to be enabled 
> concurrently.
> It's too late for that bio.
>
> - Eric

Re: [f2fs-dev] [PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

I think I don't understand how verity works.
Right after verity is enabled on a file, is the verity logic working
for the whole file data area?
Or it's just working for the data area which is updated after verity is enabled?

2020년 12월 4일 (금) 오후 1:51, Eric Biggers 님이 작성:
>
> On Fri, Dec 04, 2020 at 01:48:24PM +0900, Daeho Jeong wrote:
> > Eric,
> >
> > I have another question.
> > I understand enabling the verity can be possible in the middle of I/O.
> > Is the opposite way also possible? Actually, I couldn't find any
> > disabling function of it, though.
> >
>
> No, disabling fs-verity on a file isn't possible.
>
> - Eric

Re: [f2fs-dev] [PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

Eric,

I have another question.
I understand enabling the verity can be possible in the middle of I/O.
Is the opposite way also possible? Actually, I couldn't find any
disabling function of it, though.

2020년 12월 4일 (금) 오후 1:31, Daeho Jeong 님이 작성:
>
> > Are you sure?  I thought that compression (and encryption) apply to the 
> > whole
> > file, including any Merkle tree blocks past i_size.
>
> This "dic" structure is only for "de"compression, so we don't need to
> worry about going beyond i_size case.
>
> > Also, even if you include the i_size check, it's still wrong to check
> > fsverity_active() in the middle of the I/O because FS_IOC_ENABLE_VERITY can
> > execute concurrently, causing fsverity_active() to return false at the 
> > beginning
> > of the I/O and true later in the I/O.  It needs to be checked only once, at 
> > the
> > beginning...
>
> Got it. Our previous implementation didn't consider this case. Need to fix 
> this.
>
> Thanks,

Re: [f2fs-dev] [PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

> Are you sure?  I thought that compression (and encryption) apply to the whole
> file, including any Merkle tree blocks past i_size.

This "dic" structure is only for "de"compression, so we don't need to
worry about going beyond i_size case.

> Also, even if you include the i_size check, it's still wrong to check
> fsverity_active() in the middle of the I/O because FS_IOC_ENABLE_VERITY can
> execute concurrently, causing fsverity_active() to return false at the 
> beginning
> of the I/O and true later in the I/O.  It needs to be checked only once, at 
> the
> beginning...

Got it. Our previous implementation didn't consider this case. Need to fix this.

Thanks,

Re: [f2fs-dev] [PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

STEP_VERITY is enabled by f2fs_need_verity() and the function is like below.
We already know the second condition (idx < DIV_ROUND_UP...) is
satisfied when invoking f2fs_alloc_dic().

static inline bool f2fs_need_verity(const struct inode *inode, pgoff_t idx)
{
return fsverity_active(inode) &&
   idx < DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
}

2020년 12월 4일 (금) 오후 12:28, Eric Biggers 님이 작성:
>
> On Fri, Dec 04, 2020 at 09:58:47AM +0900, Daeho Jeong wrote:
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 87090da8693d..cdf72e153da0 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -803,8 +803,6 @@ void f2fs_decompress_pages(struct bio *bio, struct page 
> > *page, bool verity)
> >   if (cops->destroy_decompress_ctx)
> >   cops->destroy_decompress_ctx(dic);
> >  out_free_dic:
> > - if (verity)
> > - atomic_set(&dic->pending_pages, dic->nr_cpages);
> >   if (!verity)
> >   f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
> >   ret, false);
> > @@ -1498,6 +1496,8 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct 
> > compress_ctx *cc)
> >   dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
> >   dic->inode = cc->inode;
> >   atomic_set(&dic->pending_pages, cc->nr_cpages);
> > + if (fsverity_active(cc->inode))
> > + atomic_set(&dic->verity_pages, cc->nr_cpages);
> >   dic->cluster_idx = cc->cluster_idx;
> >   dic->cluster_size = cc->cluster_size;
> >   dic->log_cluster_size = cc->log_cluster_size;
>
> The check for fsverity_active() is wrong.  It looks like you need to know
> whether the bio needs to go through the fs-verity data verification.  The
> correct way to determine that is to check whether STEP_VERITY is enabled in 
> the
> bio's bio_post_read_ctx.  It's set by f2fs_grab_read_bio() when needed.
>
> - Eric

[PATCH] f2fs: fix race of pending_pages in decompression

[Daeho Jeong]

From: Daeho Jeong 

I found out f2fs_free_dic() is invoked in a wrong timing, but
f2fs_verify_bio() still needed the dic info and it triggered the
below kernel panic. It has been caused by the race condition of
pending_pages value between decompression and verity logic, when
the same compression cluster had been split in different bios.
By split bios, f2fs_verify_bio() ended up with decreasing
pending_pages value before it is reset to nr_cpages by
f2fs_decompress_pages() and caused the kernel panic.

[ 4416.564763] Unable to handle kernel NULL pointer dereference
   at virtual address 
...
[ 4416.896016] Workqueue: fsverity_read_queue f2fs_verity_work
[ 4416.908515] pc : fsverity_verify_page+0x20/0x78
[ 4416.913721] lr : f2fs_verify_bio+0x11c/0x29c
[ 4416.913722] sp : ffc019533cd0
[ 4416.913723] x29: ffc019533cd0 x28: 0402
[ 4416.913724] x27: 0001 x26: 0100
[ 4416.913726] x25: 0001 x24: 0004
[ 4416.913727] x23: 1000 x22: 
[ 4416.913728] x21:  x20: 2076f9c0
[ 4416.913729] x19: 2076f9c0 x18: ff8a32380c30
[ 4416.913731] x17: ffc01f966d97 x16: 0298
[ 4416.913732] x15:  x14: 
[ 4416.913733] x13: f074faec89ff x12: 
[ 4416.913734] x11: 1000 x10: 1000
[ 4416.929176] x9 : 20d1f5c7 x8 : 
[ 4416.929178] x7 : 626d7464ff286b6b x6 : ffc019533ade
[ 4416.929179] x5 : 8049000e x4 : 2793e9e0
[ 4416.929180] x3 : 8049000e x2 : ff89ecfa74d0
[ 4416.929181] x1 : 0c40 x0 : 2076f9c0
[ 4416.929184] Call trace:
[ 4416.929187]  fsverity_verify_page+0x20/0x78
[ 4416.929189]  f2fs_verify_bio+0x11c/0x29c
[ 4416.929192]  f2fs_verity_work+0x58/0x84
[ 4417.050667]  process_one_work+0x270/0x47c
[ 4417.055354]  worker_thread+0x27c/0x4d8
[ 4417.059784]  kthread+0x13c/0x320
[ 4417.063693]  ret_from_fork+0x10/0x18

Signed-off-by: Daeho Jeong 
---
 fs/f2fs/compress.c |  4 ++--
 fs/f2fs/data.c | 24 +++-
 fs/f2fs/f2fs.h |  1 +
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 87090da8693d..cdf72e153da0 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -803,8 +803,6 @@ void f2fs_decompress_pages(struct bio *bio, struct page 
*page, bool verity)
if (cops->destroy_decompress_ctx)
cops->destroy_decompress_ctx(dic);
 out_free_dic:
-   if (verity)
-   atomic_set(&dic->pending_pages, dic->nr_cpages);
if (!verity)
f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
ret, false);
@@ -1498,6 +1496,8 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct 
compress_ctx *cc)
dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
dic->inode = cc->inode;
atomic_set(&dic->pending_pages, cc->nr_cpages);
+   if (fsverity_active(cc->inode))
+   atomic_set(&dic->verity_pages, cc->nr_cpages);
dic->cluster_idx = cc->cluster_idx;
dic->cluster_size = cc->cluster_size;
dic->log_cluster_size = cc->log_cluster_size;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 42254d3859c7..be0567dcace9 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -202,7 +202,7 @@ static void f2fs_verify_bio(struct bio *bio)
dic = (struct decompress_io_ctx *)page_private(page);
 
if (dic) {
-   if (atomic_dec_return(&dic->pending_pages))
+   if (atomic_dec_return(&dic->verity_pages))
continue;
f2fs_verify_pages(dic->rpages,
dic->cluster_size);
@@ -2266,15 +2266,29 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, 
struct bio **bio_ret,
is_readahead ? REQ_RAHEAD : 0,
page->index, for_write);
if (IS_ERR(bio)) {
+   unsigned int remained = dic->nr_cpages - i;
+   bool release = false;
+
ret = PTR_ERR(bio);
dic->failed = true;
-   if (!atomic_sub_return(dic->nr_cpages - i,
-   &dic->pending_pages)) {
+
+   if (fsverity_active(inode)) {
+   if (!atomic_sub_return(remained,
+   &dic->verity_pages))
+   release = true;
+   } else {
+  

[PATCH v3] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

From: Daeho Jeong 

Added two ioctl to decompress/compress explicitly the compression
enabled file in "compress_mode=user" mount option.

Using these two ioctls, the users can make a control of compression
and decompression of their files.

Signed-off-by: Daeho Jeong 
---
v3: changed error condition and use get_dirty_pages for flush routine
v2: reformed codes based on comments and put gradual flush routine
---
 fs/f2fs/file.c| 185 ++
 include/uapi/linux/f2fs.h |   2 +
 2 files changed, 187 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index be8db06aca27..3678e25ed17a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4026,6 +4026,185 @@ static int f2fs_ioc_set_compress_option(struct file 
*filp, unsigned long arg)
return ret;
 }
 
+static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
+{
+   DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
+   struct address_space *mapping = inode->i_mapping;
+   struct page *page;
+   pgoff_t redirty_idx = page_idx;
+   int i, page_len = 0, ret = 0;
+
+   page_cache_ra_unbounded(&ractl, len, 0);
+
+   for (i = 0; i < len; i++, page_idx++) {
+   page = read_cache_page(mapping, page_idx, NULL, NULL);
+   if (IS_ERR(page)) {
+   ret = PTR_ERR(page);
+   break;
+   }
+   page_len++;
+   }
+
+   for (i = 0; i < page_len; i++, redirty_idx++) {
+   page = find_lock_page(mapping, redirty_idx);
+   if (!page)
+   ret = -ENOENT;
+   set_page_dirty(page);
+   f2fs_put_page(page, 1);
+   f2fs_put_page(page, 0);
+   }
+
+   return ret;
+}
+
+static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_inode_info *fi = F2FS_I(inode);
+   pgoff_t page_idx = 0, last_idx;
+   unsigned int blk_per_seg = sbi->blocks_per_seg;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi) ||
+   F2FS_OPTION(sbi).compress_mode != COMPR_MODE_USER)
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (!f2fs_is_compress_backend_ready(inode)) {
+   ret = -EOPNOTSUPP;
+   goto out;
+   }
+
+   if (f2fs_is_mmap_file(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+   if (ret)
+   goto out;
+
+   if (!atomic_read(&fi->i_compr_blocks))
+   goto out;
+
+   last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+   count = last_idx - page_idx;
+   while (count) {
+   int len = min(cluster_size, count);
+
+   ret = redirty_blocks(inode, page_idx, len);
+   if (ret < 0)
+   break;
+
+   if (get_dirty_pages(inode) >= blk_per_seg)
+   filemap_fdatawrite(inode->i_mapping);
+
+   count -= len;
+   page_idx += len;
+   }
+
+   if (!ret)
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0,
+   LLONG_MAX);
+
+   if (ret)
+   f2fs_warn(sbi, "%s: The file might be partially decompressed "
+   "(errno=%d). Please delete the file.\n",
+   __func__, ret);
+out:
+   inode_unlock(inode);
+   file_end_write(filp);
+
+   return ret;
+}
+
+static int f2fs_ioc_compress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   pgoff_t page_idx = 0, last_idx;
+   unsigned int blk_per_seg = sbi->blocks_per_seg;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi) ||
+   F2FS_OPTION(sbi).compress_mode != COMPR_MODE_USER)
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (!f2fs_is_compress_backend_ready(inode)) {
+ 

Re: [f2fs-dev] [PATCH v7 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Oh, by the control logic changed in the previous patch, we don't need
to use f2fs_is_compress_algorithm_valid() anymore.
Looks good~

2020년 12월 3일 (목) 오전 11:49, Chao Yu 님이 작성:
>
> Jaegeuk, not sure, is it too late to merge this cleanup into original patch?
>
>  From a5c63ec58e0cda6eb5d186b46942eea46422b7a9 Mon Sep 17 00:00:00 2001
> From: Chao Yu 
> Date: Thu, 3 Dec 2020 10:04:26 +0800
> Subject: [PATCH] f2fs: remove f2fs_is_compress_algorithm_valid() for cleanup
>
> No logic changes.
>
> Signed-off-by: Chao Yu 
> ---
>   fs/f2fs/compress.c | 5 -
>   fs/f2fs/f2fs.h | 5 -
>   fs/f2fs/file.c | 2 +-
>   3 files changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> index dfadbc78946c..869b047a4801 100644
> --- a/fs/f2fs/compress.c
> +++ b/fs/f2fs/compress.c
> @@ -574,11 +574,6 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
> return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
>   }
>
> -bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
> -{
> -   return f2fs_cops[algorithm] != NULL;
> -}
> -
>   static mempool_t *compress_page_pool;
>   static int num_compress_pages = 512;
>   module_param(num_compress_pages, uint, 0444);
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index b70c8d553439..17b45c2d2b04 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -3882,7 +3882,6 @@ bool f2fs_compress_write_end(struct inode *inode, void 
> *fsdata,
>   int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
>   void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
>   bool f2fs_is_compress_backend_ready(struct inode *inode);
> -bool f2fs_is_compress_algorithm_valid(unsigned char algorithm);
>   int f2fs_init_compress_mempool(void);
>   void f2fs_destroy_compress_mempool(void);
>   void f2fs_do_decompress_pages(struct decompress_io_ctx *dic, bool verity);
> @@ -3927,10 +3926,6 @@ static inline bool 
> f2fs_is_compress_backend_ready(struct inode *inode)
> /* not support compression */
> return false;
>   }
> -static inline bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
> -{
> -   return false;
> -}
>   static inline struct page *f2fs_compress_control_page(struct page *page)
>   {
> WARN_ON_ONCE(1);
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 300355fe25f0..0453b441228d 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -4016,7 +4016,7 @@ static int f2fs_ioc_set_compress_option(struct file 
> *filp, unsigned long arg)
> F2FS_I(inode)->i_cluster_size = 1 << option.log_cluster_size;
> f2fs_mark_inode_dirty_sync(inode, true);
>
> -   if (!f2fs_is_compress_algorithm_valid(option.algorithm))
> +   if (!f2fs_is_compress_backend_ready(inode))
> f2fs_warn(sbi, "compression algorithm is successfully set, "
> "but current kernel doesn't support this algorithm.");
>   out:
> --
> 2.26.2
>
>
>
>
>
> On 2020/10/30 12:10, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
> > compression option of a file.
> >
> > struct f2fs_comp_option {
> >  u8 algorithm; => compression algorithm
> >    => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
> >  u8 log_cluster_size;  => log scale cluster size
> >=> 2 ~ 8
> > };
> >
> > struct f2fs_comp_option option;
> >
> > option.algorithm = 1;
> > option.log_cluster_size = 7;
> >
> > ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >
> > v6: changed the function name of checking compression algorithm validity.
> > v5: allowed to set algorithm which is not currently enabled by kernel.
> > v4: changed commit message.
> > v3: changed the error number more specific.
> >  folded in fix for build breakage reported by kernel test robot
> >   and Dan Carpenter .
> > v2: added ioctl description.
> > ---
> >   fs/f2fs/compress.c |  5 +
> >   fs/f2fs/f2fs.h |  7 ++
> >   fs/f2fs/file.c | 54 ++
> >   3 files changed, 66 insertions(+)
> >
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 7895186cc765..b0144670d320 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode 
> > *inode)
> >  

Re: [f2fs-dev] [PATCH v2 1/2] f2fs: add compress_mode mount option

[Daeho Jeong]

Yep, you're right~ :)

2020년 12월 3일 (목) 오전 10:16, Chao Yu 님이 작성:
>
> On 2020/12/2 18:54, Daeho Jeong wrote:
> > We might use compress_extension=*,compress_option=user.
> > In this option, we're gonna allocate all the writes in cold zone.
>
> Oh, so all files in data partition will be tagged as compressed file,
> but the compressing time will be controlled by user, then, only blocks
> belong to in-compress-process inode will go to cold area, right?
>
> Thanks,
>
> >
> >
> > 2020년 12월 2일 (수) 오후 3:31, Chao Yu  > <mailto:yuch...@huawei.com>>님이 작성:
> >
> > On 2020/12/1 12:08, Daeho Jeong wrote:
> >  > From: Daeho Jeong  > <mailto:daehoje...@google.com>>
> >  >
> >  > We will add a new "compress_mode" mount option to control file
> >  > compression mode. This supports "fs" and "user". In "fs" mode 
> > (default),
> >  > f2fs does automatic compression on the compression enabled files.
> >  > In "user" mode, f2fs disables the automaic compression and gives the
> >  > user discretion of choosing the target file and the timing. It means
> >  > the user can do manual compression/decompression on the compression
> >  > enabled files using ioctls.
> >  >
> >  > Signed-off-by: Daeho Jeong  > <mailto:daehoje...@google.com>>
> >  > ---
> >  > v2: changed mount option name and added more explanation of mount 
> > option
> >  > ---
> >  >   Documentation/filesystems/f2fs.rst | 35 
> > ++
> >  >   fs/f2fs/compress.c |  2 +-
> >  >   fs/f2fs/data.c |  2 +-
> >  >   fs/f2fs/f2fs.h | 30 +
> >  >   fs/f2fs/segment.c  |  2 +-
> >  >   fs/f2fs/super.c| 23 
> >  >   6 files changed, 91 insertions(+), 3 deletions(-)
> >  >
> >  > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> >  > index b8ee761c9922..5eb8d63439ec 100644
> >  > --- a/Documentation/filesystems/f2fs.rst
> >  > +++ b/Documentation/filesystems/f2fs.rst
> >  > @@ -260,6 +260,13 @@ compress_extension=%s Support adding 
> > specified extension, so that f2fs can enab
> >  >For other files, we can still enable 
> > compression via ioctl.
> >  >Note that, there is one reserved special 
> > extension '*', it
> >  >can be set to enable compression for all 
> > files.
> >  > +compress_mode=%s  Control file compression mode. This supports 
> > "fs" and "user"
> >  > +  modes. In "fs" mode (default), f2fs does 
> > automatic compression
> >  > +  on the compression enabled files. In "user" 
> > mode, f2fs disables
> >  > +  the automaic compression and gives the user 
> > discretion of
> >  > +  choosing the target file and the timing. The 
> > user can do manual
> >  > +  compression/decompression on the compression 
> > enabled files using
> >  > +  ioctls.
> >  >   inlinecrypt  When possible, encrypt/decrypt the contents 
> > of encrypted
> >  >files using the blk-crypto framework rather 
> > than
> >  >filesystem-layer encryption. This allows the 
> > use of
> >  > @@ -810,6 +817,34 @@ Compress metadata layout::
> >  >   | data length | data chksum | reserved |  compressed data  
> >  |
> >  >   
> > +-+-+--++
> >  >
> >  > +Compression mode
> >  > +--
> >  > +
> >  > +f2fs supports "fs" and "user" compression modes with 
> > "compression_mode" mount option.
> >  > +With this option, f2fs provides a choice to select the way how to 
> > compress the
> >  > +compression enabled files (refer to "Compression implementation" 
> > section for how to
> >  > +enable compression on a reg

[PATCH v2 1/2] f2fs: add compress_mode mount option

[Daeho Jeong]

From: Daeho Jeong 

We will add a new "compress_mode" mount option to control file
compression mode. This supports "fs" and "user". In "fs" mode (default),
f2fs does automatic compression on the compression enabled files.
In "user" mode, f2fs disables the automaic compression and gives the
user discretion of choosing the target file and the timing. It means
the user can do manual compression/decompression on the compression
enabled files using ioctls.

Signed-off-by: Daeho Jeong 
---
v2: changed mount option name and added more explanation of mount option
---
 Documentation/filesystems/f2fs.rst | 35 ++
 fs/f2fs/compress.c |  2 +-
 fs/f2fs/data.c |  2 +-
 fs/f2fs/f2fs.h | 30 +
 fs/f2fs/segment.c  |  2 +-
 fs/f2fs/super.c| 23 
 6 files changed, 91 insertions(+), 3 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index b8ee761c9922..5eb8d63439ec 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -260,6 +260,13 @@ compress_extension=%s   Support adding specified 
extension, so that f2fs can enab
 For other files, we can still enable compression via 
ioctl.
 Note that, there is one reserved special extension 
'*', it
 can be set to enable compression for all files.
+compress_mode=%sControl file compression mode. This supports "fs" and 
"user"
+modes. In "fs" mode (default), f2fs does automatic 
compression
+on the compression enabled files. In "user" mode, f2fs 
disables
+the automaic compression and gives the user discretion 
of
+choosing the target file and the timing. The user can 
do manual
+compression/decompression on the compression enabled 
files using
+ioctls.
 inlinecrypt When possible, encrypt/decrypt the contents of 
encrypted
 files using the blk-crypto framework rather than
 filesystem-layer encryption. This allows the use of
@@ -810,6 +817,34 @@ Compress metadata layout::
| data length | data chksum | reserved |  compressed data   |
+-+-+--++
 
+Compression mode
+--
+
+f2fs supports "fs" and "user" compression modes with "compression_mode" mount 
option.
+With this option, f2fs provides a choice to select the way how to compress the
+compression enabled files (refer to "Compression implementation" section for 
how to
+enable compression on a regular inode).
+
+1) compress_mode=fs
+This is the default option. f2fs does automatic compression in the writeback 
of the
+compression enabled files.
+
+2) compress_mode=user
+This disables the automaic compression and gives the user discretion of 
choosing the
+target file and the timing. The user can do manual compression/decompression 
on the
+compression enabled files using F2FS_IOC_DECOMPRESS_FILE and 
F2FS_IOC_COMPRESS_FILE
+ioctls like the below.
+
+To decompress a file,
+
+fd = open(filename, O_WRONLY, 0);
+ret = ioctl(fd, F2FS_IOC_DECOMPRESS_FILE);
+
+To compress a file,
+
+fd = open(filename, O_WRONLY, 0);
+ret = ioctl(fd, F2FS_IOC_COMPRESS_FILE);
+
 NVMe Zoned Namespace devices
 
 
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 3957a84a185e..87090da8693d 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -926,7 +926,7 @@ int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t 
index)
 
 static bool cluster_may_compress(struct compress_ctx *cc)
 {
-   if (!f2fs_compressed_file(cc->inode))
+   if (!f2fs_need_compress_data(cc->inode))
return false;
if (f2fs_is_atomic_file(cc->inode))
return false;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index be4da52604ed..42254d3859c7 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3164,7 +3164,7 @@ static inline bool __should_serialize_io(struct inode 
*inode,
if (IS_NOQUOTA(inode))
return false;
 
-   if (f2fs_compressed_file(inode))
+   if (f2fs_need_compress_data(inode))
return true;
if (wbc->sync_mode != WB_SYNC_ALL)
return true;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e0826779a101..94d16bde5e24 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -149,6 +149,7 @@ struct f2fs_mount_info {
unsigned char compress_algorithm;   /* algorithm type */
unsigned compress_log_size; /* clust

[PATCH v2 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

From: Daeho Jeong 

Added two ioctl to decompress/compress explicitly the compression
enabled file in "compress_mode=user" mount option.

Using these two ioctls, the users can make a control of compression
and decompression of their files.

Signed-off-by: Daeho Jeong 
---
v2: reformed codes based on comments and put gradual flush routine
---
 fs/f2fs/file.c| 185 ++
 include/uapi/linux/f2fs.h |   2 +
 2 files changed, 187 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index be8db06aca27..300355fe25f0 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4026,6 +4026,185 @@ static int f2fs_ioc_set_compress_option(struct file 
*filp, unsigned long arg)
return ret;
 }
 
+static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
+{
+   DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
+   struct address_space *mapping = inode->i_mapping;
+   struct page *page;
+   pgoff_t redirty_idx = page_idx;
+   int i, page_len = 0, ret = 0;
+
+   page_cache_ra_unbounded(&ractl, len, 0);
+
+   for (i = 0; i < len; i++, page_idx++) {
+   page = read_cache_page(mapping, page_idx, NULL, NULL);
+   if (IS_ERR(page)) {
+   ret = PTR_ERR(page);
+   break;
+   }
+   page_len++;
+   }
+
+   for (i = 0; i < page_len; i++, redirty_idx++) {
+   page = find_lock_page(mapping, redirty_idx);
+   if (!page)
+   ret = -ENOENT;
+   set_page_dirty(page);
+   f2fs_put_page(page, 1);
+   f2fs_put_page(page, 0);
+   }
+
+   return ret;
+}
+
+static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_inode_info *fi = F2FS_I(inode);
+   pgoff_t page_idx = 0, last_idx;
+   unsigned int blk_per_seg = sbi->blocks_per_seg, dirtied = 0;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi) ||
+   F2FS_OPTION(sbi).compress_mode != COMPR_MODE_USER)
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   if (!f2fs_is_compress_backend_ready(inode))
+   return -ENOPKG;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+   if (ret)
+   goto out;
+
+   if (!atomic_read(&fi->i_compr_blocks))
+   goto out;
+
+   last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+   count = last_idx - page_idx;
+   while (count) {
+   int len = min(cluster_size, count);
+
+   ret = redirty_blocks(inode, page_idx, len);
+   if (ret < 0)
+   break;
+
+   count -= len;
+   page_idx += len;
+   dirtied += len;
+   if (dirtied >= blk_per_seg) {
+   filemap_fdatawrite(inode->i_mapping);
+   dirtied = 0;
+   }
+   }
+
+   if (!ret)
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0,
+   LLONG_MAX);
+
+   if (ret)
+   f2fs_warn(sbi, "%s: The file might be partially decompressed "
+   "(errno=%d). Please delete the file.\n",
+   __func__, ret);
+out:
+   inode_unlock(inode);
+   file_end_write(filp);
+
+   return ret;
+}
+
+static int f2fs_ioc_compress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   pgoff_t page_idx = 0, last_idx;
+   unsigned int blk_per_seg = sbi->blocks_per_seg, dirtied = 0;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi) ||
+   F2FS_OPTION(sbi).compress_mode != COMPR_MODE_USER)
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   if (!f2fs_is_compress_backend_ready(inode))
+   return -ENOPKG;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+   file_start_write(filp);
+   inode_lock(inode);
+

Re: [f2fs-dev] [PATCH] f2fs: add compr_inode and compr_blocks sysfs nodes

[Daeho Jeong]

Sure, but I don't think we need to expose compr_inode and compr_block right now.

2020년 11월 27일 (금) 오후 6:44, Chao Yu 님이 작성:
>
> Daeho,
>
> How about updating this patch based on below patch?
>
> f2fs: introduce a new per-sb directory in sysfs
>
> On 2020/10/22 10:53, Daeho Jeong wrote:
> > Yep, It sounds good to me.
> >
> > 2020년 10월 21일 (수) 오후 3:08, Chao Yu 님이 작성:
> >>
> >> On 2020/10/16 13:14, Daeho Jeong wrote:
> >>> From: Daeho Jeong 
> >>>
> >>> Added compr_inode to show compressed inode count and compr_blocks to
> >>> show compressed block count in sysfs.
> >>
> >> As there are so many entries in ../f2fs// directory, it looks a mess
> >> there, I suggest that we can add a new directory 'stats' in 
> >> ../f2fs//,
> >> in where we can store all readonly stats related entries there later.
> >>
> >> How do you think?
> >>
> >> Thanks,
> >>
> >>>
> >>> Signed-off-by: Daeho Jeong 
> >>> ---
> >>>Documentation/ABI/testing/sysfs-fs-f2fs | 10 ++
> >>>fs/f2fs/sysfs.c | 17 +
> >>>2 files changed, 27 insertions(+)
> >>>
> >>> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs 
> >>> b/Documentation/ABI/testing/sysfs-fs-f2fs
> >>> index 834d0becae6d..a01c26484c69 100644
> >>> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> >>> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> >>> @@ -350,3 +350,13 @@ Date:April 2020
> >>>Contact:"Daeho Jeong" 
> >>>Description:Give a way to change iostat_period time. 3secs by 
> >>> default.
> >>>The new iostat trace gives stats gap given the period.
> >>> +
> >>> +What:/sys/fs/f2fs//compr_inode
> >>> +Date:October 2020
> >>> +Contact: "Daeho Jeong" 
> >>> +Description: Show compressed inode count
> >>> +
> >>> +What:/sys/fs/f2fs//compr_blocks
> >>> +Date:October 2020
> >>> +Contact: "Daeho Jeong" 
> >>> +Description: Show compressed block count
> >>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> >>> index 94c98e412aa1..7139a29a00d3 100644
> >>> --- a/fs/f2fs/sysfs.c
> >>> +++ b/fs/f2fs/sysfs.c
> >>> @@ -223,6 +223,19 @@ static ssize_t avg_vblocks_show(struct f2fs_attr *a,
> >>>f2fs_update_sit_info(sbi);
> >>>return sprintf(buf, "%llu\n", (unsigned long 
> >>> long)(si->avg_vblocks));
> >>>}
> >>> +
> >>> +static ssize_t compr_inode_show(struct f2fs_attr *a,
> >>> + struct f2fs_sb_info *sbi, char *buf)
> >>> +{
> >>> + return sprintf(buf, "%u\n", atomic_read(&sbi->compr_inode));
> >>> +}
> >>> +
> >>> +static ssize_t compr_blocks_show(struct f2fs_attr *a,
> >>> + struct f2fs_sb_info *sbi, char *buf)
> >>> +{
> >>> + return sprintf(buf, "%llu\n", atomic64_read(&sbi->compr_blocks));
> >>> +}
> >>> +
> >>>#endif
> >>>
> >>>static ssize_t main_blkaddr_show(struct f2fs_attr *a,
> >>> @@ -591,6 +604,8 @@ F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, 
> >>> gc_background_calls, bg_gc);
> >>>F2FS_GENERAL_RO_ATTR(moved_blocks_background);
> >>>F2FS_GENERAL_RO_ATTR(moved_blocks_foreground);
> >>>F2FS_GENERAL_RO_ATTR(avg_vblocks);
> >>> +F2FS_GENERAL_RO_ATTR(compr_inode);
> >>> +F2FS_GENERAL_RO_ATTR(compr_blocks);
> >>>#endif
> >>>
> >>>#ifdef CONFIG_FS_ENCRYPTION
> >>> @@ -675,6 +690,8 @@ static struct attribute *f2fs_attrs[] = {
> >>>ATTR_LIST(moved_blocks_foreground),
> >>>ATTR_LIST(moved_blocks_background),
> >>>ATTR_LIST(avg_vblocks),
> >>> + ATTR_LIST(compr_inode),
> >>> + ATTR_LIST(compr_blocks),
> >>>#endif
> >>>NULL,
> >>>};
> >>>
> > .
> >

Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

Re-thinking about this, page_cache_sync_readahead() is not good for
our situation, it might end up with cluster misaligned reads which
trigger internal duplicated cluster reads.

2020년 11월 27일 (금) 오전 8:46, Daeho Jeong 님이 작성:
>
> Chao,
>
> Got it~
>
> Eric,
>
> Actually, I wanted to detour the internal readahead mechanism using
> page_cache_ra_unbounded() to generate cluster size aligned read
> requests.
> But, page_cache_async_readahead() or page_cache_sync_readahead() can
> be also good enough, since those can compensate for the misaligned
> reads reading more pages in advance.
>
> Thanks,
>
> 2020년 11월 27일 (금) 오전 2:49, Eric Biggers 님이 작성:
> >
> > On Thu, Nov 26, 2020 at 02:04:41PM +0900, Daeho Jeong wrote:
> > > Eric,
> > >
> > > do_page_cache_ra() is defined in mm/internal.h for internal use
> > > between in mm, so we cannot use this one right now.
> > > So, I think we could use page_cache_ra_unbounded(), because we already
> > > check i_size boundary on our own.
> > > What do you think?
> >
> > What about page_cache_async_readahead() or page_cache_sync_readahead()?
> >
> > - Eric

Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

Chao,

Got it~

Eric,

Actually, I wanted to detour the internal readahead mechanism using
page_cache_ra_unbounded() to generate cluster size aligned read
requests.
But, page_cache_async_readahead() or page_cache_sync_readahead() can
be also good enough, since those can compensate for the misaligned
reads reading more pages in advance.

Thanks,

2020년 11월 27일 (금) 오전 2:49, Eric Biggers 님이 작성:
>
> On Thu, Nov 26, 2020 at 02:04:41PM +0900, Daeho Jeong wrote:
> > Eric,
> >
> > do_page_cache_ra() is defined in mm/internal.h for internal use
> > between in mm, so we cannot use this one right now.
> > So, I think we could use page_cache_ra_unbounded(), because we already
> > check i_size boundary on our own.
> > What do you think?
>
> What about page_cache_async_readahead() or page_cache_sync_readahead()?
>
> - Eric

Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

Chao,

> A little bit wired, why not failing cluster_may_compress() for user mode, and
> let writepages write cluster as raw blocks, in-where we can update 
> i_compr_blocks
> and global compr block stats correctly.

For decompression ioctl, I've made f2fs_need_compress_data() return
"false" to prevent compression write, so we don't use
f2fs_write_compressed_pages() anymore in this case.
Because of this, I manually updated i_compr_blocks. Do you have any
suggestions on this?

2020년 11월 26일 (목) 오후 2:04, Daeho Jeong 님이 작성:
>
> Eric,
>
> do_page_cache_ra() is defined in mm/internal.h for internal use
> between in mm, so we cannot use this one right now.
> So, I think we could use page_cache_ra_unbounded(), because we already
> check i_size boundary on our own.
> What do you think?
>
> 2020년 11월 24일 (화) 오후 12:05, Chao Yu 님이 작성:
> >
> > On 2020/11/23 11:17, Daeho Jeong wrote:
> > > From: Daeho Jeong 
> > >
> > > Added two ioctl to decompress/compress explicitly the compression
> > > enabled file in "compress_mode=user-based" mount option.
> > >
> > > Using these two ioctls, the users can make a control of compression
> > > and decompression of their files.
> > >
> > > Signed-off-by: Daeho Jeong 
> > > ---
> > >   fs/f2fs/file.c| 181 +-
> > >   include/uapi/linux/f2fs.h |   2 +
> > >   2 files changed, 182 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > > index be8db06aca27..e8f142470e87 100644
> > > --- a/fs/f2fs/file.c
> > > +++ b/fs/f2fs/file.c
> > > @@ -4026,6 +4026,180 @@ static int f2fs_ioc_set_compress_option(struct 
> > > file *filp, unsigned long arg)
> > >   return ret;
> > >   }
> > >
> > > +static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
> > > +{
> > > + DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
> > > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > > + struct address_space *mapping = inode->i_mapping;
> > > + struct page *page;
> > > + pgoff_t redirty_idx = page_idx;
> > > + int i, page_len = 0, ret = 0;
> > > +
> > > + page_cache_ra_unbounded(&ractl, len, 0);
> > > +
> > > + for (i = 0; i < len; i++, page_idx++) {
> > > + page = read_cache_page(mapping, page_idx, NULL, NULL);
> > > + if (IS_ERR(page)) {
> > > + ret = PTR_ERR(page);
> > > + f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
> > > + "couldn't be read (errno:%d).\n",
> > > + __func__, inode->i_ino, page_idx, ret);
> >
> > This is a common error case during calling read_cache_page(), IMO, this 
> > looks
> > more like a debug log, so I prefer to print nothing here, or at least using
> > f2fs_debug() instead.
> >
> > > + break;
> > > + }
> > > + page_len++;
> > > + }
> > > +
> > > + for (i = 0; i < page_len; i++, redirty_idx++) {
> > > + page = find_lock_page(mapping, redirty_idx);
> > > + if (!page) {
> > > + ret = -ENOENT;
> > > + f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
> > > + "couldn't be found (errno:%d).\n",
> > > + __func__, inode->i_ino, redirty_idx, ret);
> >
> > Ditto.
> >
> > > + }
> > > + set_page_dirty(page);
> > > + f2fs_put_page(page, 1);
> > > + f2fs_put_page(page, 0);
> > > + }
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
> > > +{
> > > + struct inode *inode = file_inode(filp);
> > > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > > + struct f2fs_inode_info *fi = F2FS_I(inode);
> > > + pgoff_t page_idx = 0, last_idx;
> > > + int cluster_size = F2FS_I(inode)->i_cluster_size;
> > > + int count, ret;
> > > +
> > > + if (!f2fs_sb_has_compression(sbi))
> > > + return -EOPNOTSUPP;
> > > +
> > > +

Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

Eric,

do_page_cache_ra() is defined in mm/internal.h for internal use
between in mm, so we cannot use this one right now.
So, I think we could use page_cache_ra_unbounded(), because we already
check i_size boundary on our own.
What do you think?

2020년 11월 24일 (화) 오후 12:05, Chao Yu 님이 작성:
>
> On 2020/11/23 11:17, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added two ioctl to decompress/compress explicitly the compression
> > enabled file in "compress_mode=user-based" mount option.
> >
> > Using these two ioctls, the users can make a control of compression
> > and decompression of their files.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >   fs/f2fs/file.c| 181 +-
> >   include/uapi/linux/f2fs.h |   2 +
> >   2 files changed, 182 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index be8db06aca27..e8f142470e87 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -4026,6 +4026,180 @@ static int f2fs_ioc_set_compress_option(struct file 
> > *filp, unsigned long arg)
> >   return ret;
> >   }
> >
> > +static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
> > +{
> > + DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct address_space *mapping = inode->i_mapping;
> > + struct page *page;
> > + pgoff_t redirty_idx = page_idx;
> > + int i, page_len = 0, ret = 0;
> > +
> > + page_cache_ra_unbounded(&ractl, len, 0);
> > +
> > + for (i = 0; i < len; i++, page_idx++) {
> > + page = read_cache_page(mapping, page_idx, NULL, NULL);
> > + if (IS_ERR(page)) {
> > + ret = PTR_ERR(page);
> > + f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
> > + "couldn't be read (errno:%d).\n",
> > + __func__, inode->i_ino, page_idx, ret);
>
> This is a common error case during calling read_cache_page(), IMO, this looks
> more like a debug log, so I prefer to print nothing here, or at least using
> f2fs_debug() instead.
>
> > + break;
> > + }
> > + page_len++;
> > + }
> > +
> > + for (i = 0; i < page_len; i++, redirty_idx++) {
> > + page = find_lock_page(mapping, redirty_idx);
> > + if (!page) {
> > + ret = -ENOENT;
> > + f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
> > + "couldn't be found (errno:%d).\n",
> > + __func__, inode->i_ino, redirty_idx, ret);
>
> Ditto.
>
> > + }
> > + set_page_dirty(page);
> > + f2fs_put_page(page, 1);
> > + f2fs_put_page(page, 0);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
> > +{
> > + struct inode *inode = file_inode(filp);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct f2fs_inode_info *fi = F2FS_I(inode);
> > + pgoff_t page_idx = 0, last_idx;
> > + int cluster_size = F2FS_I(inode)->i_cluster_size;
> > + int count, ret;
> > +
> > + if (!f2fs_sb_has_compression(sbi))
> > + return -EOPNOTSUPP;
> > +
> > + if (!(filp->f_mode & FMODE_WRITE))
> > + return -EBADF;
> > +
> > + if (!f2fs_compressed_file(inode))
> > + return -EINVAL;
>
> Before compressubg/decompressing file, should we check whether current inode's
> compress algorithm backend is available in f2fs module?
>
> > +
> > + f2fs_balance_fs(F2FS_I_SB(inode), true);
> > +
> > + file_start_write(filp);
> > + inode_lock(inode);
> > +
> > + if (f2fs_is_mmap_file(inode)) {
> > + ret = -EBUSY;
> > + goto out;
> > + }
> > +
> > + ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
> > + if (ret)
> > + goto out;
> > +
> > + if (!atomic_read(&fi->i_compr_blocks))
> > + goto out;
> > +
> > + last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
> > +
> > + count = last_idx - pag

Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

2020년 11월 24일 (화) 오전 8:29, Eric Biggers 님이 작성:
>
> On Tue, Nov 24, 2020 at 08:02:21AM +0900, Daeho Jeong wrote:
> > Jaegeuk,
> >
> > My mistake~
> >
> > Eric,
> >
> > What I want is like do_page_cache_ra(), but I used
> > page_cache_ra_unbounded() directly, because we already checked that
> > read is within i_size.
> >
> > Or we could use do_page_cache_ra(), but it might do the same check in it 
> > again.
> > What do you think?
>
> page_cache_ra_unbounded() is basically a quirk for how fs-verity is 
> implemented
> in ext4 and f2fs.  I don't think people would be happy if it's used in other
> cases, where it's not needed.  Checking against i_size multiple times is fine.
>

Got your point. Thanks.

> >
> > I could add some description about these in
> > Documentation/filesystems/f2fs.rst and I implemented tests internally.
>
> Documentation in f2fs.rst sounds good.  All the f2fs ioctls should be
> documented there.
>
> The tests should be runnable by any kernel developer; "internal" tests aren't
> very useful.  Could you add tests to xfstests?
>

Yes, I'll add all the internal test cases to xfstests soon~

> - Eric

Re: [f2fs-dev] [PATCH 1/2] f2fs: add compress_mode mount option

[Daeho Jeong]

Jaegeuk,

Got it.

Eric,

Yep.

2020년 11월 24일 (화) 오전 3:46, Eric Biggers 님이 작성:
>
> On Mon, Nov 23, 2020 at 12:17:50PM +0900, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > We will add a new "compress_mode" mount option to control file
> > compression mode. This supports "fs-based" and "user-based".
> > In "fs-based" mode (default), f2fs does automatic compression on
> > the compression enabled files. In "user-based" mode, f2fs disables
> > the automaic compression and gives the user discretion of choosing
> > the target file and the timing. It means the user can do manual
> > compression/decompression on the compression enabled files using ioctls.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >  Documentation/filesystems/f2fs.rst |  7 +++
> >  fs/f2fs/data.c | 10 +-
> >  fs/f2fs/f2fs.h | 30 ++
> >  fs/f2fs/segment.c  |  2 +-
> >  fs/f2fs/super.c| 23 +++
> >  5 files changed, 66 insertions(+), 6 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst 
> > b/Documentation/filesystems/f2fs.rst
> > index b8ee761c9922..0679c53d5012 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -260,6 +260,13 @@ compress_extension=%s Support adding specified 
> > extension, so that f2fs can enab
> >For other files, we can still enable compression via 
> > ioctl.
> >Note that, there is one reserved special extension 
> > '*', it
> >can be set to enable compression for all files.
> > +compress_mode=%s  Control file compression mode. This supports 
> > "fs-based" and
> > +  "user-based". In "fs-based" mode (default), f2fs does
> > +  automatic compression on the compression enabled 
> > files.
> > +  In "user-based" mode, f2fs disables the automaic 
> > compression
> > +  and gives the user discretion of choosing the target 
> > file and
> > +  the timing. The user can do manual 
> > compression/decompression
> > +  on the compression enabled files using ioctls.
>
> Please clarify in the documentation what it means for compression-enabled 
> files
> to not be compressed.  It is not obvious.
>
> - Eric

Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

Jaegeuk,

My mistake~

Eric,

What I want is like do_page_cache_ra(), but I used
page_cache_ra_unbounded() directly, because we already checked that
read is within i_size.
Or we could use do_page_cache_ra(), but it might do the same check in it again.
What do you think?

I could add some description about these in
Documentation/filesystems/f2fs.rst and I implemented tests internally.

2020년 11월 24일 (화) 오전 3:48, Eric Biggers 님이 작성:
>
> On Mon, Nov 23, 2020 at 12:17:51PM +0900, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added two ioctl to decompress/compress explicitly the compression
> > enabled file in "compress_mode=user-based" mount option.
> >
> > Using these two ioctls, the users can make a control of compression
> > and decompression of their files.
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >  fs/f2fs/file.c| 181 +-
> >  include/uapi/linux/f2fs.h |   2 +
> >  2 files changed, 182 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index be8db06aca27..e8f142470e87 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -4026,6 +4026,180 @@ static int f2fs_ioc_set_compress_option(struct file 
> > *filp, unsigned long arg)
> >   return ret;
> >  }
> >
> > +static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
> > +{
> > + DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct address_space *mapping = inode->i_mapping;
> > + struct page *page;
> > + pgoff_t redirty_idx = page_idx;
> > + int i, page_len = 0, ret = 0;
> > +
> > + page_cache_ra_unbounded(&ractl, len, 0);
>
> Using page_cache_ra_unbounded() here looks wrong.  See the comment above
> page_cache_ra_unbounded().
>
> >  static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned 
> > long arg)
> >  {
> >   switch (cmd) {
> > @@ -4113,6 +4287,10 @@ static long __f2fs_ioctl(struct file *filp, unsigned 
> > int cmd, unsigned long arg)
> >   return f2fs_ioc_get_compress_option(filp, arg);
> >   case F2FS_IOC_SET_COMPRESS_OPTION:
> >   return f2fs_ioc_set_compress_option(filp, arg);
> > + case F2FS_IOC_DECOMPRESS_FILE:
> > + return f2fs_ioc_decompress_file(filp, arg);
> > + case F2FS_IOC_COMPRESS_FILE:
> > + return f2fs_ioc_compress_file(filp, arg);
> >   default:
> >   return -ENOTTY;
> >   }
>
> Where is the documentation and tests for these new ioctls?
>
> - Eric

[PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

From: Daeho Jeong 

Added two ioctl to decompress/compress explicitly the compression
enabled file in "compress_mode=user-based" mount option.

Using these two ioctls, the users can make a control of compression
and decompression of their files.

Signed-off-by: Daeho Jeong 
---
 fs/f2fs/file.c| 181 +-
 include/uapi/linux/f2fs.h |   2 +
 2 files changed, 182 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index be8db06aca27..e8f142470e87 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4026,6 +4026,180 @@ static int f2fs_ioc_set_compress_option(struct file 
*filp, unsigned long arg)
return ret;
 }
 
+static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
+{
+   DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct address_space *mapping = inode->i_mapping;
+   struct page *page;
+   pgoff_t redirty_idx = page_idx;
+   int i, page_len = 0, ret = 0;
+
+   page_cache_ra_unbounded(&ractl, len, 0);
+
+   for (i = 0; i < len; i++, page_idx++) {
+   page = read_cache_page(mapping, page_idx, NULL, NULL);
+   if (IS_ERR(page)) {
+   ret = PTR_ERR(page);
+   f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
+   "couldn't be read (errno:%d).\n",
+   __func__, inode->i_ino, page_idx, ret);
+   break;
+   }
+   page_len++;
+   }
+
+   for (i = 0; i < page_len; i++, redirty_idx++) {
+   page = find_lock_page(mapping, redirty_idx);
+   if (!page) {
+   ret = -ENOENT;
+   f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
+   "couldn't be found (errno:%d).\n",
+   __func__, inode->i_ino, redirty_idx, ret);
+   }
+   set_page_dirty(page);
+   f2fs_put_page(page, 1);
+   f2fs_put_page(page, 0);
+   }
+
+   return ret;
+}
+
+static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_inode_info *fi = F2FS_I(inode);
+   pgoff_t page_idx = 0, last_idx;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+   if (ret)
+   goto out;
+
+   if (!atomic_read(&fi->i_compr_blocks))
+   goto out;
+
+   last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+   count = last_idx - page_idx;
+   while (count) {
+   int len = min(cluster_size, count);
+
+   ret = redirty_blocks(inode, page_idx, len);
+
+   if (ret < 0)
+   break;
+
+   page_idx += len;
+   count -= len;
+   }
+
+   if (!ret)
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0,
+   LLONG_MAX);
+
+   if (!ret) {
+   stat_sub_compr_blocks(inode, atomic_read(&fi->i_compr_blocks));
+   atomic_set(&fi->i_compr_blocks, 0);
+   f2fs_mark_inode_dirty_sync(inode, true);
+   } else {
+   f2fs_warn(sbi, "%s: The file might be partially decompressed "
+   "(errno=%d). Please delete the file.\n",
+   __func__, ret);
+   }
+out:
+   inode_unlock(inode);
+   file_end_write(filp);
+
+   return ret;
+}
+
+static int f2fs_ioc_compress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   pgoff_t page_idx = 0, last_idx;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+

[PATCH 1/2] f2fs: add compress_mode mount option

[Daeho Jeong]

From: Daeho Jeong 

We will add a new "compress_mode" mount option to control file
compression mode. This supports "fs-based" and "user-based".
In "fs-based" mode (default), f2fs does automatic compression on
the compression enabled files. In "user-based" mode, f2fs disables
the automaic compression and gives the user discretion of choosing
the target file and the timing. It means the user can do manual
compression/decompression on the compression enabled files using ioctls.

Signed-off-by: Daeho Jeong 
---
 Documentation/filesystems/f2fs.rst |  7 +++
 fs/f2fs/data.c | 10 +-
 fs/f2fs/f2fs.h | 30 ++
 fs/f2fs/segment.c  |  2 +-
 fs/f2fs/super.c| 23 +++
 5 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index b8ee761c9922..0679c53d5012 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -260,6 +260,13 @@ compress_extension=%s   Support adding specified 
extension, so that f2fs can enab
 For other files, we can still enable compression via 
ioctl.
 Note that, there is one reserved special extension 
'*', it
 can be set to enable compression for all files.
+compress_mode=%sControl file compression mode. This supports 
"fs-based" and
+"user-based". In "fs-based" mode (default), f2fs does
+automatic compression on the compression enabled files.
+In "user-based" mode, f2fs disables the automaic 
compression
+and gives the user discretion of choosing the target 
file and
+the timing. The user can do manual 
compression/decompression
+on the compression enabled files using ioctls.
 inlinecrypt When possible, encrypt/decrypt the contents of 
encrypted
 files using the blk-crypto framework rather than
 filesystem-layer encryption. This allows the use of
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index be4da52604ed..69370f0073dd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2896,7 +2896,7 @@ static int f2fs_write_data_page(struct page *page,
if (unlikely(f2fs_cp_error(F2FS_I_SB(inode
goto out;
 
-   if (f2fs_compressed_file(inode)) {
+   if (f2fs_need_compress_write(inode)) {
if (f2fs_is_compressed_cluster(inode, page->index)) {
redirty_page_for_writepage(wbc, page);
return AOP_WRITEPAGE_ACTIVATE;
@@ -2988,7 +2988,7 @@ static int f2fs_write_cache_pages(struct address_space 
*mapping,
 readd:
need_readd = false;
 #ifdef CONFIG_F2FS_FS_COMPRESSION
-   if (f2fs_compressed_file(inode)) {
+   if (f2fs_need_compress_write(inode)) {
ret = f2fs_init_compress_ctx(&cc);
if (ret) {
done = 1;
@@ -3067,7 +3067,7 @@ static int f2fs_write_cache_pages(struct address_space 
*mapping,
goto continue_unlock;
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
-   if (f2fs_compressed_file(inode)) {
+   if (f2fs_need_compress_write(inode)) {
get_page(page);
f2fs_compress_ctx_add_page(&cc, page);
continue;
@@ -3120,7 +3120,7 @@ static int f2fs_write_cache_pages(struct address_space 
*mapping,
}
 #ifdef CONFIG_F2FS_FS_COMPRESSION
/* flush remained pages in compress cluster */
-   if (f2fs_compressed_file(inode) && !f2fs_cluster_is_empty(&cc)) {
+   if (f2fs_need_compress_write(inode) && !f2fs_cluster_is_empty(&cc)) {
ret = f2fs_write_multi_pages(&cc, &submitted, wbc, io_type);
nwritten += submitted;
wbc->nr_to_write -= submitted;
@@ -3164,7 +3164,7 @@ static inline bool __should_serialize_io(struct inode 
*inode,
if (IS_NOQUOTA(inode))
return false;
 
-   if (f2fs_compressed_file(inode))
+   if (f2fs_need_compress_write(inode))
return true;
if (wbc->sync_mode != WB_SYNC_ALL)
return true;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e0826779a101..88e012d07ad5 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -149,6 +149,7 @@ struct f2fs_mount_info {
unsigned char compress_algorithm;   /* algorithm type */
unsigned compress_log_size; /* cluster 

[PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE

[Daeho Jeong]

From: Daeho Jeong 

Added two ioctl to decompress/compress explicitly the compression
enabled file in disable_auto_compr mount option.

Using these two ioctls, the users can make a control of compression
and decompression of their files.

Signed-off-by: Daeho Jeong 
---
 fs/f2fs/f2fs.h |  10 ++-
 fs/f2fs/file.c | 182 +
 2 files changed, 191 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c473c78699bc..0dd3be63ac66 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -436,6 +436,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
struct f2fs_comp_option)
+#define F2FS_IOC_DECOMPRESS_FILE   _IO(F2FS_IOCTL_MAGIC, 23)
+#define F2FS_IOC_COMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 24)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -762,6 +764,8 @@ enum {
FI_VERITY_IN_PROGRESS,  /* building fs-verity Merkle tree */
FI_COMPRESSED_FILE, /* indicate file's data can be compressed */
FI_MMAP_FILE,   /* indicate file was mmapped */
+   FI_FORCE_UNCOMPRESS,/* indicate forcing to disable file compression 
*/
+   FI_FORCE_COMPRESS,  /* indicate forcing file compression */
FI_MAX, /* max flag, never be used */
 };
 
@@ -2841,7 +2845,11 @@ static inline int f2fs_compressed_file(struct inode 
*inode)
 
 static inline int f2fs_need_compress_write(struct inode *inode)
 {
-   if (test_opt(F2FS_I_SB(inode), DISABLE_AUTO_COMPR))
+   if (is_inode_flag_set(inode, FI_FORCE_UNCOMPRESS))
+   return 0;
+   else if (is_inode_flag_set(inode, FI_FORCE_COMPRESS))
+   return 1;
+   else if (test_opt(F2FS_I_SB(inode), DISABLE_AUTO_COMPR))
return 0;
return f2fs_compressed_file(inode);
 }
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index bd52df84219d..1e7ff96d7c6e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,182 @@ static int f2fs_ioc_get_compress_option(struct file 
*filp, unsigned long arg)
return 0;
 }
 
+static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
+{
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct address_space *mapping = inode->i_mapping;
+   struct page *page;
+   pgoff_t redirty_idx = page_idx;
+   int i, page_len = 0, ret = 0;
+
+   page_cache_readahead_unbounded(mapping, NULL, page_idx, len, 0);
+
+   for (i = 0; i < len; i++, page_idx++) {
+   page = read_cache_page(mapping, page_idx, NULL, NULL);
+   if (IS_ERR(page)) {
+   ret = PTR_ERR(page);
+   f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
+   "couldn't be read (errno:%d).\n",
+   __func__, inode->i_ino, page_idx, ret);
+   break;
+   }
+   page_len++;
+   }
+
+   for (i = 0; i < page_len; i++, redirty_idx++) {
+   page = find_lock_page(mapping, redirty_idx);
+   if (!page) {
+   ret = -ENOENT;
+   f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
+   "couldn't be found (errno:%d).\n",
+   __func__, inode->i_ino, redirty_idx, ret);
+   }
+   set_page_dirty(page);
+   f2fs_put_page(page, 1);
+   f2fs_put_page(page, 0);
+   }
+
+   return ret;
+}
+
+static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   pgoff_t page_idx = 0, last_idx;
+   int cluster_size = F2FS_I(inode)->i_cluster_size;
+   int count, ret;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (!f2fs_compressed_file(inode))
+   return -EINVAL;
+
+   f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+   if (ret)
+   goto out;
+
+   if (!F2FS_I(inode)->i_compr_blocks)
+   goto out;
+
+   set_inode_flag(inode, FI_FORCE_UNCOMPRESS);
+
+   last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+   count = last_idx - page_idx;
+   while (count) {
+   int len = min(cluster_size, count);
+

[PATCH 1/2] f2fs: add disable_auto_compr mount option

[Daeho Jeong]

From: Daeho Jeong 

We will add a new disable_auto_compr mount option to turn off the
automaic compression on the compression enabled file, in order to
give discretion of choosing the target file and the timing of
compression to the user.

Signed-off-by: Daeho Jeong 
---
 Documentation/filesystems/f2fs.rst |  4 
 fs/f2fs/data.c | 10 +-
 fs/f2fs/f2fs.h |  8 
 fs/f2fs/segment.c  |  2 +-
 fs/f2fs/super.c|  9 +
 5 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst 
b/Documentation/filesystems/f2fs.rst
index b8ee761c9922..c36ca1e0f7ab 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -260,6 +260,10 @@ compress_extension=%s   Support adding specified 
extension, so that f2fs can enab
 For other files, we can still enable compression via 
ioctl.
 Note that, there is one reserved special extension 
'*', it
 can be set to enable compression for all files.
+disable_auto_compr   Even if compression feature is enabled, this option 
can
+ disable automaic compression on the compression 
enabled
+ file to give discretion of choosing the target file 
and
+ the timing of compression to the user.
 inlinecrypt When possible, encrypt/decrypt the contents of 
encrypted
 files using the blk-crypto framework rather than
 filesystem-layer encryption. This allows the use of
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index c31ec408bd4f..414c8370ab7e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2896,7 +2896,7 @@ static int f2fs_write_data_page(struct page *page,
if (unlikely(f2fs_cp_error(F2FS_I_SB(inode
goto out;
 
-   if (f2fs_compressed_file(inode)) {
+   if (f2fs_need_compress_write(inode)) {
if (f2fs_is_compressed_cluster(inode, page->index)) {
redirty_page_for_writepage(wbc, page);
return AOP_WRITEPAGE_ACTIVATE;
@@ -2988,7 +2988,7 @@ static int f2fs_write_cache_pages(struct address_space 
*mapping,
 readd:
need_readd = false;
 #ifdef CONFIG_F2FS_FS_COMPRESSION
-   if (f2fs_compressed_file(inode)) {
+   if (f2fs_need_compress_write(inode)) {
ret = f2fs_init_compress_ctx(&cc);
if (ret) {
done = 1;
@@ -3067,7 +3067,7 @@ static int f2fs_write_cache_pages(struct address_space 
*mapping,
goto continue_unlock;
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
-   if (f2fs_compressed_file(inode)) {
+   if (f2fs_need_compress_write(inode)) {
get_page(page);
f2fs_compress_ctx_add_page(&cc, page);
continue;
@@ -3120,7 +3120,7 @@ static int f2fs_write_cache_pages(struct address_space 
*mapping,
}
 #ifdef CONFIG_F2FS_FS_COMPRESSION
/* flush remained pages in compress cluster */
-   if (f2fs_compressed_file(inode) && !f2fs_cluster_is_empty(&cc)) {
+   if (f2fs_need_compress_write(inode) && !f2fs_cluster_is_empty(&cc)) {
ret = f2fs_write_multi_pages(&cc, &submitted, wbc, io_type);
nwritten += submitted;
wbc->nr_to_write -= submitted;
@@ -3162,7 +3162,7 @@ static inline bool __should_serialize_io(struct inode 
*inode,
if (IS_NOQUOTA(inode))
return false;
 
-   if (f2fs_compressed_file(inode))
+   if (f2fs_need_compress_write(inode))
return true;
if (wbc->sync_mode != WB_SYNC_ALL)
return true;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..c473c78699bc 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -99,6 +99,7 @@ extern const char *f2fs_fault_name[FAULT_MAX];
 #define F2FS_MOUNT_DISABLE_CHECKPOINT  0x0200
 #define F2FS_MOUNT_NORECOVERY  0x0400
 #define F2FS_MOUNT_ATGC0x0800
+#define F2FS_MOUNT_DISABLE_AUTO_COMPR  0x1000
 
 #define F2FS_OPTION(sbi)   ((sbi)->mount_opt)
 #define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
@@ -2838,6 +2839,13 @@ static inline int f2fs_compressed_file(struct inode 
*inode)
is_inode_flag_set(inode, FI_COMPRESSED_FILE);
 }
 
+static inline int f2fs_need_compress_write(struct inode *inode)
+{
+   if (test_opt(F2FS_I_SB(inode), DISABLE_AUTO_COMPR))
+   return 0;
+   return f2fs_compressed_file(inode);
+}
+
 static inline unsigned int 

[PATCH v2] f2fs_io: add get/set compression option

[Daeho Jeong]

From: Daeho Jeong 

Added new commands, get_coption and set_coption, to support
F2FS_IOC_GET_COMPRESS_OPTION and F2FS_IOC_SET_COMPRESS_OPTION.

Signed-off-by: Daeho Jeong 
---

v2: changed the file open option of set_coption to write only.
---
 tools/f2fs_io/f2fs_io.c | 61 +
 tools/f2fs_io/f2fs_io.h |  9 ++
 2 files changed, 70 insertions(+)

diff --git a/tools/f2fs_io/f2fs_io.c b/tools/f2fs_io/f2fs_io.c
index 5a2d06e..7e6cfd8 100644
--- a/tools/f2fs_io/f2fs_io.c
+++ b/tools/f2fs_io/f2fs_io.c
@@ -905,6 +905,65 @@ static void do_reserve_cblocks(int argc, char **argv, 
const struct cmd_desc *cmd
exit(0);
 }
 
+#define get_coption_desc "get compression option of a compressed file"
+#define get_coption_help   \
+"f2fs_io get_coption [file]\n\n"   \
+"  algorithm: compression algorithm (0:lzo, 1: lz4, 2:zstd, 
3:lzorle)\n"   \
+"  log_cluster_size : compression cluster log size (2 <= log_size <= 8)\n"
+
+static void do_get_coption(int argc, char **argv, const struct cmd_desc *cmd)
+{
+   struct f2fs_comp_option option;
+   int ret, fd;
+
+   if (argc != 2) {
+   fputs("Excess arguments\n\n", stderr);
+   fputs(cmd->cmd_help, stderr);
+   exit(1);
+   }
+
+   fd = xopen(argv[1], O_RDONLY, 0);
+
+   ret = ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);
+   if (ret < 0)
+   die_errno("F2FS_IOC_GET_COMPRESS_OPTION failed");
+
+   printf("compression algorithm:%u\n", option.algorithm);
+   printf("compression cluster log size:%u\n", option.log_cluster_size);
+
+   exit(0);
+}
+
+#define set_coption_desc "set compression option of a compressed file"
+#define set_coption_help   \
+"f2fs_io set_coption [algorithm] [log_cluster_size] [file_path]\n\n"   \
+"  algorithm: compression algorithm (0:lzo, 1: lz4, 2:zstd, 
3:lzorle)\n"   \
+"  log_cluster_size : compression cluster log size (2 <= log_size <= 8)\n"
+
+static void do_set_coption(int argc, char **argv, const struct cmd_desc *cmd)
+{
+   struct f2fs_comp_option option;
+   int fd, ret;
+
+   if (argc != 4) {
+   fputs("Excess arguments\n\n", stderr);
+   fputs(cmd->cmd_help, stderr);
+   exit(1);
+   }
+
+   option.algorithm = atoi(argv[1]);
+   option.log_cluster_size = atoi(argv[2]);
+
+   fd = xopen(argv[3], O_WRONLY, 0);
+
+   ret = ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);
+   if (ret < 0)
+   die_errno("F2FS_IOC_SET_COMPRESS_OPTION failed");
+
+   printf("set compression option: algorithm=%u, log_cluster_size=%u\n",
+   option.algorithm, option.log_cluster_size);
+   exit(0);
+}
 
 #define CMD_HIDDEN 0x0001
 #define CMD(name) { #name, do_##name, name##_desc, name##_help, 0 }
@@ -930,6 +989,8 @@ const struct cmd_desc cmd_list[] = {
CMD(get_cblocks),
CMD(release_cblocks),
CMD(reserve_cblocks),
+   CMD(get_coption),
+   CMD(set_coption),
{ NULL, NULL, NULL, NULL, 0 }
 };
 
diff --git a/tools/f2fs_io/f2fs_io.h b/tools/f2fs_io/f2fs_io.h
index 05d4cfe..cb56e8c 100644
--- a/tools/f2fs_io/f2fs_io.h
+++ b/tools/f2fs_io/f2fs_io.h
@@ -84,6 +84,10 @@ typedef u32  __be32;
_IOR(F2FS_IOCTL_MAGIC, 18, __u64)
 #define F2FS_IOC_RESERVE_COMPRESS_BLOCKS   \
_IOR(F2FS_IOCTL_MAGIC, 19, __u64)
+#define F2FS_IOC_GET_COMPRESS_OPTION_IOR(F2FS_IOCTL_MAGIC, 21,  \
+   struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION_IOW(F2FS_IOCTL_MAGIC, 22,  \
+   struct f2fs_comp_option)
 
 #define F2FS_IOC_SET_ENCRYPTION_POLICY FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY FS_IOC_GET_ENCRYPTION_POLICY
@@ -164,3 +168,8 @@ struct f2fs_flush_device {
u32 dev_num;/* device number to flush */
u32 segments;   /* # of segments to flush */
 };
+
+struct f2fs_comp_option {
+   u8 algorithm;
+   u8 log_cluster_size;
+};
-- 
2.29.1.341.ge80a0c044ae-goog

Re: [f2fs-dev] [PATCH v7 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Oh, even if those are patchset, then I have to send just changed ones?
Got it.

2020년 10월 30일 (금) 오후 3:13, Chao Yu 님이 작성:
>
> Daeho,
>
> If there is no change, we are used to not resend the patch with updated
> version.
>
> Thanks,
>
> On 2020/10/30 12:10, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
> > compression option of a file.
> >
> > struct f2fs_comp_option {
> >  u8 algorithm; => compression algorithm
> >=> 0:lzo, 1:lz4, 2:zstd, 3:lzorle
> >  u8 log_cluster_size;  => log scale cluster size
> >=> 2 ~ 8
> > };
> >
> > struct f2fs_comp_option option;
> >
> > option.algorithm = 1;
> > option.log_cluster_size = 7;
> >
> > ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >
> > v6: changed the function name of checking compression algorithm validity.
> > v5: allowed to set algorithm which is not currently enabled by kernel.
> > v4: changed commit message.
> > v3: changed the error number more specific.
> >  folded in fix for build breakage reported by kernel test robot
> >   and Dan Carpenter .
> > v2: added ioctl description.
> > ---
> >   fs/f2fs/compress.c |  5 +
> >   fs/f2fs/f2fs.h |  7 ++
> >   fs/f2fs/file.c | 54 ++
> >   3 files changed, 66 insertions(+)
> >
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 7895186cc765..b0144670d320 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode 
> > *inode)
> >   return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
> >   }
> >
> > +bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
> > +{
> > + return f2fs_cops[algorithm] != NULL;
> > +}
> > +
> >   static mempool_t *compress_page_pool;
> >   static int num_compress_pages = 512;
> >   module_param(num_compress_pages, uint, 0444);
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index a33c90cf979b..70a8a2196888 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct 
> > f2fs_journal *journal,
> >   struct f2fs_sectrim_range)
> >   #define F2FS_IOC_GET_COMPRESS_OPTION_IOR(F2FS_IOCTL_MAGIC, 21,
> >   \
> >   struct f2fs_comp_option)
> > +#define F2FS_IOC_SET_COMPRESS_OPTION _IOW(F2FS_IOCTL_MAGIC, 22,  \
> > + struct f2fs_comp_option)
> >
> >   /*
> >* should be same as XFS_IOC_GOINGDOWN.
> > @@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, 
> > void *fsdata,
> >   int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool 
> > lock);
> >   void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
> >   bool f2fs_is_compress_backend_ready(struct inode *inode);
> > +bool f2fs_is_compress_algorithm_valid(unsigned char algorithm);
> >   int f2fs_init_compress_mempool(void);
> >   void f2fs_destroy_compress_mempool(void);
> >   void f2fs_decompress_pages(struct bio *bio, struct page *page, bool 
> > verity);
> > @@ -3945,6 +3948,10 @@ static inline bool 
> > f2fs_is_compress_backend_ready(struct inode *inode)
> >   /* not support compression */
> >   return false;
> >   }
> > +static inline bool f2fs_is_compress_algorithm_valid(unsigned char 
> > algorithm)
> > +{
> > + return false;
> > +}
> >   static inline struct page *f2fs_compress_control_page(struct page *page)
> >   {
> >   WARN_ON_ONCE(1);
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index bd52df84219d..be56702e4939 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -3963,6 +3963,57 @@ static int f2fs_ioc_get_compress_option(struct file 
> > *filp, unsigned long arg)
> >   return 0;
> >   }
> >
> > +static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long 
> > arg)
> > +{
> > + struct inode *inode = file_inode(filp);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct f2fs_comp_option option;
> > + int ret = 0;
> > +
> > + if (!f2fs_sb

[PATCH v7 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_GET_COMPRESS_OPTION ioctl to get file compression
option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v7: changed inode_lock() to inode_lock_shared().
v4: changed commit message.
v3: changed the error number more specific.
v2: added ioctl description.
---
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 30 ++
 2 files changed, 37 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53fe2853579c..a33c90cf979b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -433,6 +433,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
_IOR(F2FS_IOCTL_MAGIC, 19, __u64)
 #define F2FS_IOC_SEC_TRIM_FILE _IOW(F2FS_IOCTL_MAGIC, 20,  \
struct f2fs_sectrim_range)
+#define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -481,6 +483,11 @@ struct f2fs_sectrim_range {
u64 flags;
 };
 
+struct f2fs_comp_option {
+   u8 algorithm;
+   u8 log_cluster_size;
+};
+
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE   1
 static inline int get_extra_isize(struct inode *inode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef5a844de53f..bd52df84219d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3936,6 +3936,33 @@ static int f2fs_sec_trim_file(struct file *filp, 
unsigned long arg)
return ret;
 }
 
+static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_comp_option option;
+
+   if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
+   return -EOPNOTSUPP;
+
+   inode_lock_shared(inode);
+
+   if (!f2fs_compressed_file(inode)) {
+   inode_unlock_shared(inode);
+   return -ENODATA;
+   }
+
+   option.algorithm = F2FS_I(inode)->i_compress_algorithm;
+   option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
+
+   inode_unlock_shared(inode);
+
+   if (copy_to_user((struct f2fs_comp_option __user *)arg, &option,
+   sizeof(option)))
+   return -EFAULT;
+
+   return 0;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4024,6 +4051,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
return f2fs_reserve_compress_blocks(filp, arg);
case F2FS_IOC_SEC_TRIM_FILE:
return f2fs_sec_trim_file(filp, arg);
+   case F2FS_IOC_GET_COMPRESS_OPTION:
+   return f2fs_ioc_get_compress_option(filp, arg);
default:
return -ENOTTY;
}
@@ -4194,6 +4223,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int 
cmd, unsigned long arg)
case F2FS_IOC_RELEASE_COMPRESS_BLOCKS:
case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:
case F2FS_IOC_SEC_TRIM_FILE:
+   case F2FS_IOC_GET_COMPRESS_OPTION:
break;
default:
return -ENOIOCTLCMD;
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v7 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
compression option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

option.algorithm = 1;
option.log_cluster_size = 7;

ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v6: changed the function name of checking compression algorithm validity.
v5: allowed to set algorithm which is not currently enabled by kernel.
v4: changed commit message.
v3: changed the error number more specific.
folded in fix for build breakage reported by kernel test robot
 and Dan Carpenter .
v2: added ioctl description.
---
 fs/f2fs/compress.c |  5 +
 fs/f2fs/f2fs.h |  7 ++
 fs/f2fs/file.c | 54 ++
 3 files changed, 66 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 7895186cc765..b0144670d320 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
 }
 
+bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
+{
+   return f2fs_cops[algorithm] != NULL;
+}
+
 static mempool_t *compress_page_pool;
 static int num_compress_pages = 512;
 module_param(num_compress_pages, uint, 0444);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..70a8a2196888 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION   _IOW(F2FS_IOCTL_MAGIC, 22,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, void 
*fsdata,
 int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
 void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
 bool f2fs_is_compress_backend_ready(struct inode *inode);
+bool f2fs_is_compress_algorithm_valid(unsigned char algorithm);
 int f2fs_init_compress_mempool(void);
 void f2fs_destroy_compress_mempool(void);
 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
@@ -3945,6 +3948,10 @@ static inline bool f2fs_is_compress_backend_ready(struct 
inode *inode)
/* not support compression */
return false;
 }
+static inline bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
+{
+   return false;
+}
 static inline struct page *f2fs_compress_control_page(struct page *page)
 {
WARN_ON_ONCE(1);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index bd52df84219d..be56702e4939 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,57 @@ static int f2fs_ioc_get_compress_option(struct file 
*filp, unsigned long arg)
return 0;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_comp_option option;
+   int ret = 0;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
+   sizeof(option)))
+   return -EFAULT;
+
+   if (!f2fs_compressed_file(inode) ||
+   option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+   option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
+   option.algorithm >= COMPRESS_MAX)
+   return -EINVAL;
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   if (inode->i_size != 0) {
+   ret = -EFBIG;
+   goto out;
+   }
+
+   F2FS_I(inode)->i_compress_algorithm = option.algorithm;
+   F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
+   F2FS_I(inode)->i_cluster_size = 1 << option.log_cluster_size;
+   f2fs_mark_inode_dirty_sync(inode, true);
+
+   if (!f2fs_is_compress_algorithm_valid(option.algorithm))
+   f2fs_warn(sbi, "compression algorithm is successfully set, "
+   "but current kernel doesn't support

Re: [f2fs-dev] [PATCH v5 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Opps, I missed this.
We need v7... lol

2020년 10월 30일 (금) 오전 11:37, Chao Yu 님이 작성:
>
> On 2020/10/29 15:24, Chao Yu wrote:
> > On 2020/10/29 12:15, Daeho Jeong wrote:
>
> >> +inode_lock(inode);
> >
> > It's minor,
> >
> > inode_lock_shared()?
> >
> >> +
> >> +if (!f2fs_compressed_file(inode)) {
> >> +inode_unlock(inode);
> >
> > inode_unlock_shared()?
> >
> >> +return -ENODATA;
> >> +}
> >> +
> >> +option.algorithm = F2FS_I(inode)->i_compress_algorithm;
> >> +option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
> >> +
> >> +inode_unlock(inode);
> >
> > ditto.
>
> Any comments?
>
> Thanks,

[PATCH v6 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_GET_COMPRESS_OPTION ioctl to get file compression
option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v4: changed commit message.
v3: changed the error number more specific.
v2: added ioctl description.
---
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 30 ++
 2 files changed, 37 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53fe2853579c..a33c90cf979b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -433,6 +433,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
_IOR(F2FS_IOCTL_MAGIC, 19, __u64)
 #define F2FS_IOC_SEC_TRIM_FILE _IOW(F2FS_IOCTL_MAGIC, 20,  \
struct f2fs_sectrim_range)
+#define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -481,6 +483,11 @@ struct f2fs_sectrim_range {
u64 flags;
 };
 
+struct f2fs_comp_option {
+   u8 algorithm;
+   u8 log_cluster_size;
+};
+
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE   1
 static inline int get_extra_isize(struct inode *inode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef5a844de53f..8922ab191a9d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3936,6 +3936,33 @@ static int f2fs_sec_trim_file(struct file *filp, 
unsigned long arg)
return ret;
 }
 
+static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_comp_option option;
+
+   if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
+   return -EOPNOTSUPP;
+
+   inode_lock(inode);
+
+   if (!f2fs_compressed_file(inode)) {
+   inode_unlock(inode);
+   return -ENODATA;
+   }
+
+   option.algorithm = F2FS_I(inode)->i_compress_algorithm;
+   option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
+
+   inode_unlock(inode);
+
+   if (copy_to_user((struct f2fs_comp_option __user *)arg, &option,
+   sizeof(option)))
+   return -EFAULT;
+
+   return 0;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4024,6 +4051,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
return f2fs_reserve_compress_blocks(filp, arg);
case F2FS_IOC_SEC_TRIM_FILE:
return f2fs_sec_trim_file(filp, arg);
+   case F2FS_IOC_GET_COMPRESS_OPTION:
+   return f2fs_ioc_get_compress_option(filp, arg);
default:
return -ENOTTY;
}
@@ -4194,6 +4223,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int 
cmd, unsigned long arg)
case F2FS_IOC_RELEASE_COMPRESS_BLOCKS:
case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:
case F2FS_IOC_SEC_TRIM_FILE:
+   case F2FS_IOC_GET_COMPRESS_OPTION:
break;
default:
return -ENOIOCTLCMD;
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v6 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
compression option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

option.algorithm = 1;
option.log_cluster_size = 7;

ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v6: changed the function name of checking compression algorithm validity.
v5: allowed to set algorithm which is not currently enabled by kernel.
v4: changed commit message.
v3: changed the error number more specific.
folded in fix for build breakage reported by kernel test robot
 and Dan Carpenter .
v2: added ioctl description.
---
 fs/f2fs/compress.c |  5 +
 fs/f2fs/f2fs.h |  7 ++
 fs/f2fs/file.c | 54 ++
 3 files changed, 66 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 7895186cc765..b0144670d320 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
 }
 
+bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
+{
+   return f2fs_cops[algorithm] != NULL;
+}
+
 static mempool_t *compress_page_pool;
 static int num_compress_pages = 512;
 module_param(num_compress_pages, uint, 0444);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..70a8a2196888 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION   _IOW(F2FS_IOCTL_MAGIC, 22,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, void 
*fsdata,
 int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
 void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
 bool f2fs_is_compress_backend_ready(struct inode *inode);
+bool f2fs_is_compress_algorithm_valid(unsigned char algorithm);
 int f2fs_init_compress_mempool(void);
 void f2fs_destroy_compress_mempool(void);
 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
@@ -3945,6 +3948,10 @@ static inline bool f2fs_is_compress_backend_ready(struct 
inode *inode)
/* not support compression */
return false;
 }
+static inline bool f2fs_is_compress_algorithm_valid(unsigned char algorithm)
+{
+   return false;
+}
 static inline struct page *f2fs_compress_control_page(struct page *page)
 {
WARN_ON_ONCE(1);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 8922ab191a9d..9fbe98a90301 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,57 @@ static int f2fs_ioc_get_compress_option(struct file 
*filp, unsigned long arg)
return 0;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_comp_option option;
+   int ret = 0;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
+   sizeof(option)))
+   return -EFAULT;
+
+   if (!f2fs_compressed_file(inode) ||
+   option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+   option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
+   option.algorithm >= COMPRESS_MAX)
+   return -EINVAL;
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   if (inode->i_size != 0) {
+   ret = -EFBIG;
+   goto out;
+   }
+
+   F2FS_I(inode)->i_compress_algorithm = option.algorithm;
+   F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
+   F2FS_I(inode)->i_cluster_size = 1 << option.log_cluster_size;
+   f2fs_mark_inode_dirty_sync(inode, true);
+
+   if (!f2fs_is_compress_algorithm_valid(option.algorithm))
+   f2fs_warn(sbi, "compression algorithm is successfully set, "
+   "but current kernel doesn't support

Re: [f2fs-dev] [PATCH v5 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Chao, got it on f2fs_is_compress_algorithm_valid().
I also agree on Eric's opinion on that error value.

2020년 10월 30일 (금) 오전 12:54, Eric Biggers 님이 작성:
>
> On Thu, Oct 29, 2020 at 03:29:17PM +0800, Chao Yu wrote:
> > > +static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long 
> > > arg)
> > > +{
> > > +   struct inode *inode = file_inode(filp);
> > > +   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > > +   struct f2fs_comp_option option;
> > > +   int ret = 0;
> > > +
> > > +   if (!f2fs_sb_has_compression(sbi))
> > > +   return -EOPNOTSUPP;
> > > +
> > > +   if (!(filp->f_mode & FMODE_WRITE))
> > > +   return -EBADF;
> > > +
> > > +   if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
> > > +   sizeof(option)))
> > > +   return -EFAULT;
> > > +
> > > +   if (!f2fs_compressed_file(inode) ||
> > > +   option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
> > > +   option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
> > > +   option.algorithm >= COMPRESS_MAX)
> > > +   return -EINVAL;
> > > +
> > > +   file_start_write(filp);
> > > +   inode_lock(inode);
> > > +
> > > +   if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
> > > +   ret = -EBUSY;
> > > +   goto out;
> > > +   }
> > > +
> > > +   if (inode->i_size != 0) {
> > > +   ret = -EFBIG;
> > > +   goto out;
> > > +   }
> >
> > Hmm...
> >
> > Shouldn't it be:
> >
> > if (algorithm >= COMPRESS_MAX) {
> >   ret = -ENOPKG;
> >   goto out;
> > }
> >
> > if (!f2fs_cops[algorithm])
> >   f2fs_warn(...);
>
> Note that my intent with recommending ENOPKG was for it to be returned in the
> !f2fs_cops[algorithm] case, similar to how opening an encrypted file when the
> encryption algorithm is recognized but not supported by the kernel returns
> ENOPKG.  For a truly unrecognized algorithm (algorithm >= COMPRESS_MAX), 
> EINVAL
> would probably be more appropriate.  So if !f2fs_cops[algorithm] is now 
> allowed,
> then ENOPKG should no longer be among the error codes this ioctl returns.
>
> - Eric

[PATCH v5 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_GET_COMPRESS_OPTION ioctl to get file compression
option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v4: changed commit message.
v3: changed the error number more specific.
v2: added ioctl description.
---
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 30 ++
 2 files changed, 37 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53fe2853579c..a33c90cf979b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -433,6 +433,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
_IOR(F2FS_IOCTL_MAGIC, 19, __u64)
 #define F2FS_IOC_SEC_TRIM_FILE _IOW(F2FS_IOCTL_MAGIC, 20,  \
struct f2fs_sectrim_range)
+#define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -481,6 +483,11 @@ struct f2fs_sectrim_range {
u64 flags;
 };
 
+struct f2fs_comp_option {
+   u8 algorithm;
+   u8 log_cluster_size;
+};
+
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE   1
 static inline int get_extra_isize(struct inode *inode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef5a844de53f..8922ab191a9d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3936,6 +3936,33 @@ static int f2fs_sec_trim_file(struct file *filp, 
unsigned long arg)
return ret;
 }
 
+static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_comp_option option;
+
+   if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
+   return -EOPNOTSUPP;
+
+   inode_lock(inode);
+
+   if (!f2fs_compressed_file(inode)) {
+   inode_unlock(inode);
+   return -ENODATA;
+   }
+
+   option.algorithm = F2FS_I(inode)->i_compress_algorithm;
+   option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
+
+   inode_unlock(inode);
+
+   if (copy_to_user((struct f2fs_comp_option __user *)arg, &option,
+   sizeof(option)))
+   return -EFAULT;
+
+   return 0;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4024,6 +4051,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
return f2fs_reserve_compress_blocks(filp, arg);
case F2FS_IOC_SEC_TRIM_FILE:
return f2fs_sec_trim_file(filp, arg);
+   case F2FS_IOC_GET_COMPRESS_OPTION:
+   return f2fs_ioc_get_compress_option(filp, arg);
default:
return -ENOTTY;
}
@@ -4194,6 +4223,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int 
cmd, unsigned long arg)
case F2FS_IOC_RELEASE_COMPRESS_BLOCKS:
case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:
case F2FS_IOC_SEC_TRIM_FILE:
+   case F2FS_IOC_GET_COMPRESS_OPTION:
break;
default:
return -ENOIOCTLCMD;
-- 
2.29.1.341.ge80a0c044ae-goog

Re: [f2fs-dev] [PATCH v5 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

f2fs_cops is a static variable. Do you wanna change this to global
variable (extern)?

2020년 10월 29일 (목) 오후 4:29, Chao Yu 님이 작성:
>
> On 2020/10/29 12:15, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
> > compression option of a file.
> >
> > struct f2fs_comp_option {
> >  u8 algorithm; => compression algorithm
> >=> 0:lzo, 1:lz4, 2:zstd, 3:lzorle
> >  u8 log_cluster_size;  => log scale cluster size
> >=> 2 ~ 8
> > };
> >
> > struct f2fs_comp_option option;
> >
> > option.algorithm = 1;
> > option.log_cluster_size = 7;
> >
> > ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >
> > v5: allowed to set algorithm which is not currently enabled by kernel
> > v4: changed commit message.
> > v3: changed the error number more specific.
> >  folded in fix for build breakage reported by kernel test robot
> >   and Dan Carpenter .
> > v2: added ioctl description.
> > ---
> >   fs/f2fs/compress.c |  5 +
> >   fs/f2fs/f2fs.h |  7 ++
> >   fs/f2fs/file.c | 54 ++
> >   3 files changed, 66 insertions(+)
> >
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 7895186cc765..816d7adc914c 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode 
> > *inode)
> >   return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
> >   }
> >
> > +bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
> > +{
> > + return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
> > +}
> > +
> >   static mempool_t *compress_page_pool;
> >   static int num_compress_pages = 512;
> >   module_param(num_compress_pages, uint, 0444);
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index a33c90cf979b..cc38afde6c04 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct 
> > f2fs_journal *journal,
> >   struct f2fs_sectrim_range)
> >   #define F2FS_IOC_GET_COMPRESS_OPTION_IOR(F2FS_IOCTL_MAGIC, 21,
> >   \
> >   struct f2fs_comp_option)
> > +#define F2FS_IOC_SET_COMPRESS_OPTION _IOW(F2FS_IOCTL_MAGIC, 22,  \
> > + struct f2fs_comp_option)
> >
> >   /*
> >* should be same as XFS_IOC_GOINGDOWN.
> > @@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, 
> > void *fsdata,
> >   int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool 
> > lock);
> >   void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
> >   bool f2fs_is_compress_backend_ready(struct inode *inode);
> > +bool f2fs_is_compress_algorithm_ready(unsigned char algorithm);
> >   int f2fs_init_compress_mempool(void);
> >   void f2fs_destroy_compress_mempool(void);
> >   void f2fs_decompress_pages(struct bio *bio, struct page *page, bool 
> > verity);
> > @@ -3945,6 +3948,10 @@ static inline bool 
> > f2fs_is_compress_backend_ready(struct inode *inode)
> >   /* not support compression */
> >   return false;
> >   }
> > +static inline bool f2fs_is_compress_algorithm_ready(unsigned char 
> > algorithm)
> > +{
> > + return false;
> > +}
> >   static inline struct page *f2fs_compress_control_page(struct page *page)
> >   {
> >   WARN_ON_ONCE(1);
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 8922ab191a9d..a0f31d8ebcfd 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -3963,6 +3963,57 @@ static int f2fs_ioc_get_compress_option(struct file 
> > *filp, unsigned long arg)
> >   return 0;
> >   }
> >
> > +static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long 
> > arg)
> > +{
> > + struct inode *inode = file_inode(filp);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct f2fs_comp_option option;
> > + int ret = 0;
> > +
> > + if (!f2fs_sb_has_compression(sbi))
> > + return -EOPNOTSUPP;
> > +
> > + if (!(filp->f_mode & FMODE_WRITE))
> > + return -

[PATCH v5 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
compression option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

option.algorithm = 1;
option.log_cluster_size = 7;

ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v5: allowed to set algorithm which is not currently enabled by kernel
v4: changed commit message.
v3: changed the error number more specific.
folded in fix for build breakage reported by kernel test robot
 and Dan Carpenter .
v2: added ioctl description.
---
 fs/f2fs/compress.c |  5 +
 fs/f2fs/f2fs.h |  7 ++
 fs/f2fs/file.c | 54 ++
 3 files changed, 66 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 7895186cc765..816d7adc914c 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
 }
 
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+   return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
+}
+
 static mempool_t *compress_page_pool;
 static int num_compress_pages = 512;
 module_param(num_compress_pages, uint, 0444);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..cc38afde6c04 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION   _IOW(F2FS_IOCTL_MAGIC, 22,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, void 
*fsdata,
 int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
 void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
 bool f2fs_is_compress_backend_ready(struct inode *inode);
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm);
 int f2fs_init_compress_mempool(void);
 void f2fs_destroy_compress_mempool(void);
 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
@@ -3945,6 +3948,10 @@ static inline bool f2fs_is_compress_backend_ready(struct 
inode *inode)
/* not support compression */
return false;
 }
+static inline bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+   return false;
+}
 static inline struct page *f2fs_compress_control_page(struct page *page)
 {
WARN_ON_ONCE(1);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 8922ab191a9d..a0f31d8ebcfd 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,57 @@ static int f2fs_ioc_get_compress_option(struct file 
*filp, unsigned long arg)
return 0;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_comp_option option;
+   int ret = 0;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
+   sizeof(option)))
+   return -EFAULT;
+
+   if (!f2fs_compressed_file(inode) ||
+   option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+   option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
+   option.algorithm >= COMPRESS_MAX)
+   return -EINVAL;
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   if (inode->i_size != 0) {
+   ret = -EFBIG;
+   goto out;
+   }
+
+   F2FS_I(inode)->i_compress_algorithm = option.algorithm;
+   F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
+   F2FS_I(inode)->i_cluster_size = 1 << option.log_cluster_size;
+   f2fs_mark_inode_dirty_sync(inode, true);
+
+   if (!f2fs_is_compress_algorithm_ready(option.algorithm))
+   f2fs_warn(sbi, "compression algorithm is successfully set, "
+   "but current kernel doesn't support this algorithm.");
+out

Re: [f2fs-dev] [PATCH v4 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Chao,

Do you want to print out a kernel warning message in this case? like
"XX compression algorithm is set for this inode, but current mount
option doesn't support this algorithm."?

2020년 10월 28일 (수) 오후 3:47, Chao Yu 님이 작성:
>
> On 2020/10/27 13:38, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
> > compression option of a file.
> >
> > struct f2fs_comp_option {
> >  u8 algorithm; => compression algorithm
> >=> 0:lzo, 1:lz4, 2:zstd, 3:lzorle
> >  u8 log_cluster_size;  => log scale cluster size
> >=> 2 ~ 8
> > };
> >
> > struct f2fs_comp_option option;
> >
> > option.algorithm = 1;
> > option.log_cluster_size = 7;
> >
> > ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);
> >
> > Signed-off-by: Daeho Jeong 
> > ---
> >
> > v4: changed commit message.
> > v3: changed the error number more specific.
> >  folded in fix for build breakage reported by kernel test robot
> >   and Dan Carpenter .
> > v2: added ioctl description.
> > ---
> >   fs/f2fs/compress.c |  5 +
> >   fs/f2fs/f2fs.h |  7 +++
> >   fs/f2fs/file.c | 52 ++
> >   3 files changed, 64 insertions(+)
> >
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 7895186cc765..816d7adc914c 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode 
> > *inode)
> >   return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
> >   }
> >
> > +bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
> > +{
> > + return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
> > +}
> > +
> >   static mempool_t *compress_page_pool;
> >   static int num_compress_pages = 512;
> >   module_param(num_compress_pages, uint, 0444);
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index a33c90cf979b..cc38afde6c04 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct 
> > f2fs_journal *journal,
> >   struct f2fs_sectrim_range)
> >   #define F2FS_IOC_GET_COMPRESS_OPTION_IOR(F2FS_IOCTL_MAGIC, 21,
> >   \
> >   struct f2fs_comp_option)
> > +#define F2FS_IOC_SET_COMPRESS_OPTION _IOW(F2FS_IOCTL_MAGIC, 22,  \
> > + struct f2fs_comp_option)
> >
> >   /*
> >* should be same as XFS_IOC_GOINGDOWN.
> > @@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, 
> > void *fsdata,
> >   int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool 
> > lock);
> >   void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
> >   bool f2fs_is_compress_backend_ready(struct inode *inode);
> > +bool f2fs_is_compress_algorithm_ready(unsigned char algorithm);
> >   int f2fs_init_compress_mempool(void);
> >   void f2fs_destroy_compress_mempool(void);
> >   void f2fs_decompress_pages(struct bio *bio, struct page *page, bool 
> > verity);
> > @@ -3945,6 +3948,10 @@ static inline bool 
> > f2fs_is_compress_backend_ready(struct inode *inode)
> >   /* not support compression */
> >   return false;
> >   }
> > +static inline bool f2fs_is_compress_algorithm_ready(unsigned char 
> > algorithm)
> > +{
> > + return false;
> > +}
> >   static inline struct page *f2fs_compress_control_page(struct page *page)
> >   {
> >   WARN_ON_ONCE(1);
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 8922ab191a9d..8048b150e43b 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -3963,6 +3963,55 @@ static int f2fs_ioc_get_compress_option(struct file 
> > *filp, unsigned long arg)
> >   return 0;
> >   }
> >
> > +static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long 
> > arg)
> > +{
> > + struct inode *inode = file_inode(filp);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct f2fs_comp_option option;
> > + int ret = 0;
> > +
> > + if (!f2fs_sb_has_compression(sbi))
> > + return -EOPNOTSUPP;
> > +
> > + if (!(filp->f_mode & FMODE_WRIT

[PATCH v4 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
compression option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

option.algorithm = 1;
option.log_cluster_size = 7;

ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v4: changed commit message.
v3: changed the error number more specific.
folded in fix for build breakage reported by kernel test robot
 and Dan Carpenter .
v2: added ioctl description.
---
 fs/f2fs/compress.c |  5 +
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 52 ++
 3 files changed, 64 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 7895186cc765..816d7adc914c 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
 }
 
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+   return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
+}
+
 static mempool_t *compress_page_pool;
 static int num_compress_pages = 512;
 module_param(num_compress_pages, uint, 0444);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..cc38afde6c04 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION   _IOW(F2FS_IOCTL_MAGIC, 22,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, void 
*fsdata,
 int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
 void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
 bool f2fs_is_compress_backend_ready(struct inode *inode);
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm);
 int f2fs_init_compress_mempool(void);
 void f2fs_destroy_compress_mempool(void);
 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
@@ -3945,6 +3948,10 @@ static inline bool f2fs_is_compress_backend_ready(struct 
inode *inode)
/* not support compression */
return false;
 }
+static inline bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+   return false;
+}
 static inline struct page *f2fs_compress_control_page(struct page *page)
 {
WARN_ON_ONCE(1);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 8922ab191a9d..8048b150e43b 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,55 @@ static int f2fs_ioc_get_compress_option(struct file 
*filp, unsigned long arg)
return 0;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_comp_option option;
+   int ret = 0;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
+   sizeof(option)))
+   return -EFAULT;
+
+   if (!f2fs_compressed_file(inode) ||
+   option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+   option.log_cluster_size > MAX_COMPRESS_LOG_SIZE)
+   return -EINVAL;
+
+   if (!f2fs_is_compress_algorithm_ready(option.algorithm))
+   return -ENOPKG;
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   if (inode->i_size != 0) {
+   ret = -EFBIG;
+   goto out;
+   }
+
+   F2FS_I(inode)->i_compress_algorithm = option.algorithm;
+   F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
+   F2FS_I(inode)->i_cluster_size = 1 << option.log_cluster_size;
+   f2fs_mark_inode_dirty_sync(inode, true);
+out:
+   inode_unlock(inode);
+   file_end_write(filp);
+
+   return ret;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4053,6 +4102,8 @@ long f2fs_ioctl(struct file *f

[PATCH v4 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_GET_COMPRESS_OPTION ioctl to get file compression
option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
---

v4: changed commit message.
v3: changed the error number more specific.
v2: added ioctl description.
---
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 30 ++
 2 files changed, 37 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53fe2853579c..a33c90cf979b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -433,6 +433,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
_IOR(F2FS_IOCTL_MAGIC, 19, __u64)
 #define F2FS_IOC_SEC_TRIM_FILE _IOW(F2FS_IOCTL_MAGIC, 20,  \
struct f2fs_sectrim_range)
+#define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -481,6 +483,11 @@ struct f2fs_sectrim_range {
u64 flags;
 };
 
+struct f2fs_comp_option {
+   u8 algorithm;
+   u8 log_cluster_size;
+};
+
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE   1
 static inline int get_extra_isize(struct inode *inode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef5a844de53f..8922ab191a9d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3936,6 +3936,33 @@ static int f2fs_sec_trim_file(struct file *filp, 
unsigned long arg)
return ret;
 }
 
+static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_comp_option option;
+
+   if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
+   return -EOPNOTSUPP;
+
+   inode_lock(inode);
+
+   if (!f2fs_compressed_file(inode)) {
+   inode_unlock(inode);
+   return -ENODATA;
+   }
+
+   option.algorithm = F2FS_I(inode)->i_compress_algorithm;
+   option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
+
+   inode_unlock(inode);
+
+   if (copy_to_user((struct f2fs_comp_option __user *)arg, &option,
+   sizeof(option)))
+   return -EFAULT;
+
+   return 0;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4024,6 +4051,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
return f2fs_reserve_compress_blocks(filp, arg);
case F2FS_IOC_SEC_TRIM_FILE:
return f2fs_sec_trim_file(filp, arg);
+   case F2FS_IOC_GET_COMPRESS_OPTION:
+   return f2fs_ioc_get_compress_option(filp, arg);
default:
return -ENOTTY;
}
@@ -4194,6 +4223,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int 
cmd, unsigned long arg)
case F2FS_IOC_RELEASE_COMPRESS_BLOCKS:
case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:
case F2FS_IOC_SEC_TRIM_FILE:
+   case F2FS_IOC_GET_COMPRESS_OPTION:
break;
default:
return -ENOIOCTLCMD;
-- 
2.29.0.rc2.309.g374f81d7ae-goog

Re: [PATCH v3 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Oops, typos...

2020년 10월 27일 (화) 오전 8:43, Daeho Jeong 님이 작성:
>
> Oops, typos...
>
> On Tue, Oct 27, 2020 at 8:27 AM Eric Biggers  wrote:
>>
>> On Tue, Oct 27, 2020 at 08:18:44AM +0900, Daeho Jeong wrote:
>> > I checked that. We seem to need to complement missing parts including
>> > other ioctls in Documentation/filesystems/fscrypt.rst.
>> >
>> > Thanks~
>> >
>>
>> Well, the f2fs-specific ioctls should probably be documented in
>> Documentation/filesystems/f2fs.rst.
>>
>> - Eric

Re: [PATCH v3 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

I checked that. We seem to need to complement missing parts including
other ioctls in Documentation/filesystems/fscrypt.rst.

Thanks~

2020년 10월 27일 (화) 오전 8:05, Eric Biggers 님이 작성:
>
> On Tue, Oct 27, 2020 at 08:02:18AM +0900, Daeho Jeong wrote:
> > I thought I gave the information about that in the commit message. Is
> > this not enough for you?
> > Actually, there is no space for F2FS ioctl documentation now. :(
> >
>
> The commit message doesn't really matter.  What I am asking for are actual
> documentation and tests.
>
> The fscrypt ioctls, for example, are all documented in
> Documentation/filesystems/fscrypt.rst, and they have tests in xfstests.
>
> - Eric

Re: [PATCH v3 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

I thought I gave the information about that in the commit message. Is
this not enough for you?
Actually, there is no space for F2FS ioctl documentation now. :(

2020년 10월 27일 (화) 오전 4:04, Eric Biggers 님이 작성:
>
> On Mon, Oct 26, 2020 at 01:16:55PM +0900, Daeho Jeong wrote:
> > From: Daeho Jeong 
> >
> > Added a new F2FS_IOC_GET_COMPRESS_OPTION ioctl to get file compression
> > option of a file.
> >
> > struct f2fs_comp_option {
> > u8 algorithm; => compression algorithm
> >   => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
> > u8 log_cluster_size;  => log scale cluster size
> >   => 2 ~ 8
> > };
> >
> > struct f2fs_comp_option option;
> >
> > ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);
> >
> > Signed-off-by: Daeho Jeong 
> > Reviewed-by: Eric Biggers 
>
> Please don't add Reviewed-by until it is explicitly given.
>
> The actual code looks fine, but there's still no mention of documentation,
> tests, or use cases.
>
> - Eric

[PATCH v3 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_SET_COMPRESS_OPTION ioctl to change file
compression option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

option.algorithm = 1;
option.log_cluster_size = 7;

ioctl(fd, F2FS_IOC_SET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
Reviewed-by: Eric Biggers 
Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
---

v3: changed the error number more specific.
v2: added ioctl description.
---
 fs/f2fs/compress.c |  5 +
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 52 ++
 3 files changed, 64 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 7895186cc765..816d7adc914c 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
 }
 
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+   return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
+}
+
 static mempool_t *compress_page_pool;
 static int num_compress_pages = 512;
 module_param(num_compress_pages, uint, 0444);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33c90cf979b..cc38afde6c04 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -435,6 +435,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
struct f2fs_sectrim_range)
 #define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
struct f2fs_comp_option)
+#define F2FS_IOC_SET_COMPRESS_OPTION   _IOW(F2FS_IOCTL_MAGIC, 22,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -3915,6 +3917,7 @@ bool f2fs_compress_write_end(struct inode *inode, void 
*fsdata,
 int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);
 void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
 bool f2fs_is_compress_backend_ready(struct inode *inode);
+bool f2fs_is_compress_algorithm_ready(unsigned char algorithm);
 int f2fs_init_compress_mempool(void);
 void f2fs_destroy_compress_mempool(void);
 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
@@ -3945,6 +3948,10 @@ static inline bool f2fs_is_compress_backend_ready(struct 
inode *inode)
/* not support compression */
return false;
 }
+static inline bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
+{
+   return false;
+}
 static inline struct page *f2fs_compress_control_page(struct page *page)
 {
WARN_ON_ONCE(1);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 8922ab191a9d..8048b150e43b 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3963,6 +3963,55 @@ static int f2fs_ioc_get_compress_option(struct file 
*filp, unsigned long arg)
return 0;
 }
 
+static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+   struct f2fs_comp_option option;
+   int ret = 0;
+
+   if (!f2fs_sb_has_compression(sbi))
+   return -EOPNOTSUPP;
+
+   if (!(filp->f_mode & FMODE_WRITE))
+   return -EBADF;
+
+   if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
+   sizeof(option)))
+   return -EFAULT;
+
+   if (!f2fs_compressed_file(inode) ||
+   option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
+   option.log_cluster_size > MAX_COMPRESS_LOG_SIZE)
+   return -EINVAL;
+
+   if (!f2fs_is_compress_algorithm_ready(option.algorithm))
+   return -ENOPKG;
+
+   file_start_write(filp);
+   inode_lock(inode);
+
+   if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   if (inode->i_size != 0) {
+   ret = -EFBIG;
+   goto out;
+   }
+
+   F2FS_I(inode)->i_compress_algorithm = option.algorithm;
+   F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
+   F2FS_I(inode)->i_cluster_size = 1 << option.log_cluster_size;
+   f2fs_mark_inode_dirty_sync(inode, true);
+out:
+   inode_unlock(inode);
+   file_end_write(filp);
+
+   return ret;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4053,6 +4102,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, 
unsig

[PATCH v3 1/2] f2fs: add F2FS_IOC_GET_COMPRESS_OPTION ioctl

[Daeho Jeong]

From: Daeho Jeong 

Added a new F2FS_IOC_GET_COMPRESS_OPTION ioctl to get file compression
option of a file.

struct f2fs_comp_option {
u8 algorithm; => compression algorithm
  => 0:lzo, 1:lz4, 2:zstd, 3:lzorle
u8 log_cluster_size;  => log scale cluster size
  => 2 ~ 8
};

struct f2fs_comp_option option;

ioctl(fd, F2FS_IOC_GET_COMPRESS_OPTION, &option);

Signed-off-by: Daeho Jeong 
Reviewed-by: Eric Biggers 
---

v3: changed the error number more specific.
v2: added ioctl description.
---
 fs/f2fs/f2fs.h |  7 +++
 fs/f2fs/file.c | 30 ++
 2 files changed, 37 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53fe2853579c..a33c90cf979b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -433,6 +433,8 @@ static inline bool __has_cursum_space(struct f2fs_journal 
*journal,
_IOR(F2FS_IOCTL_MAGIC, 19, __u64)
 #define F2FS_IOC_SEC_TRIM_FILE _IOW(F2FS_IOCTL_MAGIC, 20,  \
struct f2fs_sectrim_range)
+#define F2FS_IOC_GET_COMPRESS_OPTION   _IOR(F2FS_IOCTL_MAGIC, 21,  \
+   struct f2fs_comp_option)
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -481,6 +483,11 @@ struct f2fs_sectrim_range {
u64 flags;
 };
 
+struct f2fs_comp_option {
+   u8 algorithm;
+   u8 log_cluster_size;
+};
+
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE   1
 static inline int get_extra_isize(struct inode *inode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef5a844de53f..8922ab191a9d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3936,6 +3936,33 @@ static int f2fs_sec_trim_file(struct file *filp, 
unsigned long arg)
return ret;
 }
 
+static int f2fs_ioc_get_compress_option(struct file *filp, unsigned long arg)
+{
+   struct inode *inode = file_inode(filp);
+   struct f2fs_comp_option option;
+
+   if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
+   return -EOPNOTSUPP;
+
+   inode_lock(inode);
+
+   if (!f2fs_compressed_file(inode)) {
+   inode_unlock(inode);
+   return -ENODATA;
+   }
+
+   option.algorithm = F2FS_I(inode)->i_compress_algorithm;
+   option.log_cluster_size = F2FS_I(inode)->i_log_cluster_size;
+
+   inode_unlock(inode);
+
+   if (copy_to_user((struct f2fs_comp_option __user *)arg, &option,
+   sizeof(option)))
+   return -EFAULT;
+
+   return 0;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)
@@ -4024,6 +4051,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
return f2fs_reserve_compress_blocks(filp, arg);
case F2FS_IOC_SEC_TRIM_FILE:
return f2fs_sec_trim_file(filp, arg);
+   case F2FS_IOC_GET_COMPRESS_OPTION:
+   return f2fs_ioc_get_compress_option(filp, arg);
default:
return -ENOTTY;
}
@@ -4194,6 +4223,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int 
cmd, unsigned long arg)
case F2FS_IOC_RELEASE_COMPRESS_BLOCKS:
case F2FS_IOC_RESERVE_COMPRESS_BLOCKS:
case F2FS_IOC_SEC_TRIM_FILE:
+   case F2FS_IOC_GET_COMPRESS_OPTION:
break;
default:
return -ENOIOCTLCMD;
-- 
2.29.0.rc1.297.gfa9743e501-goog

Re: [PATCH v2 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

Yep, sure~!

2020년 10월 23일 (금) 오후 9:00, Dan Carpenter 님이 작성:
>
> Hi Daeho,
>
> url:
> https://github.com/0day-ci/linux/commits/Daeho-Jeong/f2fs-add-F2FS_IOC_GET_COMPRESS_OPTION-ioctl/20201022-115947
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git 
> dev-test
> config: x86_64-randconfig-m001-20201022 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot 
> Reported-by: Dan Carpenter 
>
> New smatch warnings:
> fs/f2fs/file.c:4011 f2fs_ioc_set_compress_option() error: uninitialized 
> symbol 'ret'.
>
> Old smatch warnings:
> fs/f2fs/f2fs.h:2127 dec_valid_block_count() warn: should 'count << 3' be a 64 
> bit type?
> fs/f2fs/file.c:2525 f2fs_ioc_gc_range() warn: inconsistent returns 
> 'sbi->gc_lock'.
> fs/f2fs/file.c:2941 f2fs_ioc_flush_device() warn: potential spectre issue 
> 'sbi->devs' [w] (local cap)
> fs/f2fs/file.c:2966 f2fs_ioc_flush_device() warn: inconsistent returns 
> 'sbi->gc_lock'.
> fs/f2fs/file.c:3305 f2fs_precache_extents() error: uninitialized symbol 'err'.
>
> vim +/ret +4011 fs/f2fs/file.c
>
> d869d11ac39edb Daeho Jeong 2020-10-22  3969  static int 
> f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
> d869d11ac39edb Daeho Jeong 2020-10-22  3970  {
> d869d11ac39edb Daeho Jeong 2020-10-22  3971 struct inode *inode = 
> file_inode(filp);
> d869d11ac39edb Daeho Jeong 2020-10-22  3972 struct f2fs_sb_info *sbi = 
> F2FS_I_SB(inode);
> d869d11ac39edb Daeho Jeong 2020-10-22  3973 struct f2fs_comp_option 
> option;
> d869d11ac39edb Daeho Jeong 2020-10-22  3974 int ret;
> d869d11ac39edb Daeho Jeong 2020-10-22  3975
> d869d11ac39edb Daeho Jeong 2020-10-22  3976 if 
> (!f2fs_sb_has_compression(sbi))
> d869d11ac39edb Daeho Jeong 2020-10-22  3977 return -EOPNOTSUPP;
> d869d11ac39edb Daeho Jeong 2020-10-22  3978
> d869d11ac39edb Daeho Jeong 2020-10-22  3979 if 
> (!f2fs_compressed_file(inode))
> d869d11ac39edb Daeho Jeong 2020-10-22  3980 return -EINVAL;
> d869d11ac39edb Daeho Jeong 2020-10-22  3981
> d869d11ac39edb Daeho Jeong 2020-10-22  3982 if (!(filp->f_mode & 
> FMODE_WRITE))
> d869d11ac39edb Daeho Jeong 2020-10-22  3983 return -EBADF;
> d869d11ac39edb Daeho Jeong 2020-10-22  3984
> d869d11ac39edb Daeho Jeong 2020-10-22  3985 if (copy_from_user(&option, 
> (struct f2fs_comp_option __user *)arg,
> d869d11ac39edb Daeho Jeong 2020-10-22  3986 
> sizeof(option)))
> d869d11ac39edb Daeho Jeong 2020-10-22  3987 return -EFAULT;
> d869d11ac39edb Daeho Jeong 2020-10-22  3988
> d869d11ac39edb Daeho Jeong 2020-10-22  3989 if (option.log_cluster_size < 
> MIN_COMPRESS_LOG_SIZE ||
> d869d11ac39edb Daeho Jeong 2020-10-22  3990     
> option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
> d869d11ac39edb Daeho Jeong 2020-10-22  3991     
> !f2fs_is_compress_algorithm_ready(option.algorithm))
> d869d11ac39edb Daeho Jeong 2020-10-22  3992 return -EINVAL;
> d869d11ac39edb Daeho Jeong 2020-10-22  3993
> d869d11ac39edb Daeho Jeong 2020-10-22  3994 file_start_write(filp);
> d869d11ac39edb Daeho Jeong 2020-10-22  3995 inode_lock(inode);
> d869d11ac39edb Daeho Jeong 2020-10-22  3996
> d869d11ac39edb Daeho Jeong 2020-10-22  3997     if (f2fs_is_mmap_file(inode) 
> ||
> d869d11ac39edb Daeho Jeong 2020-10-22  3998     
> get_dirty_pages(inode) || inode->i_size) {
> d869d11ac39edb Daeho Jeong 2020-10-22  3999     ret = -EINVAL;
> d869d11ac39edb Daeho Jeong 2020-10-22  4000 goto out;
> d869d11ac39edb Daeho Jeong 2020-10-22  4001 }
> d869d11ac39edb Daeho Jeong 2020-10-22  4002
> d869d11ac39edb Daeho Jeong 2020-10-22  4003 
> F2FS_I(inode)->i_compress_algorithm = option.algorithm;
> d869d11ac39edb Daeho Jeong 2020-10-22  4004     
> F2FS_I(inode)->i_log_cluster_size = option.log_cluster_size;
> d869d11ac39edb Daeho Jeong 2020-10-22  4005     F2FS_I(inode)->i_cluster_size 
> = 1 << option.log_cluster_size;
> d869d11ac39edb Daeho Jeong 2020-10-22  4006     
> f2fs_mark_inode_dirty_sync(inode, true);
>
>
> "ret" is uninitialized on the success path.
>
> d869d11ac39edb Daeho Jeong 2020-10-22  4007  out:
> d869d11ac39edb Daeho Jeong 2020-10-22  4008 inode_unlock(inode);
> d869d11ac39edb Daeho Jeong 2020-10-22  4009 file_end_write(filp);
> d869d11ac39edb Daeho Jeong 2020-10-22  4010
> d869d11ac39edb Daeho Jeong 2020-10-22 @4011 return ret;
> d869d11ac39edb Daeho Jeong 2020-10-22  4012  }
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org