subject:"Re\: \[PATCH\] btrfs\: use kvzalloc for EXTENT

Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

2018-05-11 Thread David Sterba

On Fri, May 11, 2018 at 06:16:15PM +0100, Filipe Manana wrote:
> On Fri, May 11, 2018 at 5:49 PM, David Sterba  wrote:
> > On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote:
> >> On Fri, May 11, 2018 at 4:57 PM, David Sterba  wrote:
> >> > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> >> > arrays can be 32KiB large. To avoid allocation failures due to
> >> > fragmented memory, use the allocation with fallback to vmalloc.
> >> >
> >> > Signed-off-by: David Sterba 
> >> > ---
> >> >
> >> > This depends on the patches that remove the 16MiB restriction in the
> >> > dedupe ioctl, but contextually can be applied to the current code too.
> >> >
> >> > https://patchwork.kernel.org/patch/10374941/
> >> >
> >> >  fs/btrfs/ioctl.c | 4 ++--
> >> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> >> > index b572e38b4b64..a7f517009cd7 100644
> >> > --- a/fs/btrfs/ioctl.c
> >> > +++ b/fs/btrfs/ioctl.c
> >> > @@ -3178,8 +3178,8 @@ static int btrfs_extent_same(struct inode *src, 
> >> > u64 loff, u64 olen,
> >> >  * locking. We use an array for the page pointers. Size of the 
> >> > array is
> >> >  * bounded by len, which is in turn bounded by 
> >> > BTRFS_MAX_DEDUPE_LEN.
> >> >  */
> >> > -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), 
> >> > GFP_KERNEL);
> >> > -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), 
> >> > GFP_KERNEL);
> >> > +   cmp.src_pages = kvzalloc(num_pages, sizeof(struct page *), 
> >> > GFP_KERNEL);
> >> > +   cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *), 
> >> > GFP_KERNEL);
> >>
> >> Kvzalloc should take 2 parameters and not 3.
> >
> > And the right function is kvmalloc_array.
> >
> >> Also, aren't the corresponding kvfree() calls missing?
> >
> > Yes, thanks for catching it. The updated version:
> >
> > From: David Sterba 
> > Subject: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data
> >
> > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> > arrays can be 32KiB large. To avoid allocation failures due to
> > fragmented memory, use the allocation with fallback to vmalloc.
> >
> > Signed-off-by: David Sterba 
> > ---
> >  fs/btrfs/ioctl.c | 16 +---
> >  1 file changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > index b572e38b4b64..4fcfa05ed960 100644
> > --- a/fs/btrfs/ioctl.c
> > +++ b/fs/btrfs/ioctl.c
> > @@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src, u64 
> > loff, u64 olen,
> >  * locking. We use an array for the page pointers. Size of the 
> > array is
> >  * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
> >  */
> > -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), 
> > GFP_KERNEL);
> > -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), 
> > GFP_KERNEL);
> > +   cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> > +  GFP_KERNEL);
> > +   cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> > +  GFP_KERNEL);
> > if (!cmp.src_pages || !cmp.dst_pages) {
> > -   kfree(cmp.src_pages);
> > -   kfree(cmp.dst_pages);
> > -   return -ENOMEM;
> > +   ret = -ENOMEM;
> > +   goto out_free;
> > }
> >
> > if (same_inode)
> > @@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src, u64 
> > loff, u64 olen,
> > else
> > btrfs_double_inode_unlock(src, dst);
> >
> > -   kfree(cmp.src_pages);
> > -   kfree(cmp.dst_pages);
> > +out_free:
> > +   kvfree(cmp.src_pages);
> > +   kvfree(cmp.dst_pages);
> 
> kvfree() missing at btrfs_cmp_data_free() too.

Bah, no more quick fixes from me today. I'll drop the patch from the
branch and will have a fresh look another day.
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Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

2018-05-11 Thread Timofey Titovets

пт, 11 мая 2018 г. в 20:32, Omar Sandoval :

> On Fri, May 11, 2018 at 06:49:16PM +0200, David Sterba wrote:
> > On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote:
> > > On Fri, May 11, 2018 at 4:57 PM, David Sterba 
wrote:
> > > > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> > > > arrays can be 32KiB large. To avoid allocation failures due to
> > > > fragmented memory, use the allocation with fallback to vmalloc.
> > > >
> > > > Signed-off-by: David Sterba 
> > > > ---
> > > >
> > > > This depends on the patches that remove the 16MiB restriction in the
> > > > dedupe ioctl, but contextually can be applied to the current code
too.
> > > >
> > > > https://patchwork.kernel.org/patch/10374941/
> > > >
> > > >  fs/btrfs/ioctl.c | 4 ++--
> > > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > > > index b572e38b4b64..a7f517009cd7 100644
> > > > --- a/fs/btrfs/ioctl.c
> > > > +++ b/fs/btrfs/ioctl.c
> > > > @@ -3178,8 +3178,8 @@ static int btrfs_extent_same(struct inode
*src, u64 loff, u64 olen,
> > > >  * locking. We use an array for the page pointers. Size of
the array is
> > > >  * bounded by len, which is in turn bounded by
BTRFS_MAX_DEDUPE_LEN.
> > > >  */
> > > > -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *),
GFP_KERNEL);
> > > > -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *),
GFP_KERNEL);
> > > > +   cmp.src_pages = kvzalloc(num_pages, sizeof(struct page *),
GFP_KERNEL);
> > > > +   cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *),
GFP_KERNEL);
> > >
> > > Kvzalloc should take 2 parameters and not 3.
> >
> > And the right function is kvmalloc_array.
> >
> > > Also, aren't the corresponding kvfree() calls missing?
> >
> > Yes, thanks for catching it. The updated version:
> >
> > From: David Sterba 
> > Subject: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data
> >
> > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> > arrays can be 32KiB large. To avoid allocation failures due to
> > fragmented memory, use the allocation with fallback to vmalloc.
> >
> > Signed-off-by: David Sterba 
> > ---
> >  fs/btrfs/ioctl.c | 16 +---
> >  1 file changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > index b572e38b4b64..4fcfa05ed960 100644
> > --- a/fs/btrfs/ioctl.c
> > +++ b/fs/btrfs/ioctl.c
> > @@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src,
u64 loff, u64 olen,
> >* locking. We use an array for the page pointers. Size of the
array is
> >* bounded by len, which is in turn bounded by
BTRFS_MAX_DEDUPE_LEN.
> >*/
> > - cmp.src_pages = kcalloc(num_pages, sizeof(struct page *),
GFP_KERNEL);
> > - cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *),
GFP_KERNEL);
> > + cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> > +GFP_KERNEL);
> > + cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> > +GFP_KERNEL);

> kcalloc() implies __GFP_ZERO, do we need that here?

AFAIK, yes, because:
btrfs_cmp_data_free():
...
pg = cmp->src_pages[i];
if (pg) {...}
..

And we will catch that, if errors happens in gather_extent_pages().

Thanks.
> >   if (!cmp.src_pages || !cmp.dst_pages) {
> > - kfree(cmp.src_pages);
> > - kfree(cmp.dst_pages);
> > - return -ENOMEM;
> > + ret = -ENOMEM;
> > + goto out_free;
> >   }
> >
> >   if (same_inode)
> > @@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src,
u64 loff, u64 olen,
> >   else
> >   btrfs_double_inode_unlock(src, dst);
> >
> > - kfree(cmp.src_pages);
> > - kfree(cmp.dst_pages);
> > +out_free:
> > + kvfree(cmp.src_pages);
> > + kvfree(cmp.dst_pages);
> >
> >   return ret;
> >  }
> > --
> > 2.16.2
> >


-- 
Have a nice day,
Timofey.
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Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

2018-05-11 Thread Omar Sandoval

On Fri, May 11, 2018 at 06:49:16PM +0200, David Sterba wrote:
> On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote:
> > On Fri, May 11, 2018 at 4:57 PM, David Sterba  wrote:
> > > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> > > arrays can be 32KiB large. To avoid allocation failures due to
> > > fragmented memory, use the allocation with fallback to vmalloc.
> > >
> > > Signed-off-by: David Sterba 
> > > ---
> > >
> > > This depends on the patches that remove the 16MiB restriction in the
> > > dedupe ioctl, but contextually can be applied to the current code too.
> > >
> > > https://patchwork.kernel.org/patch/10374941/
> > >
> > >  fs/btrfs/ioctl.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > > index b572e38b4b64..a7f517009cd7 100644
> > > --- a/fs/btrfs/ioctl.c
> > > +++ b/fs/btrfs/ioctl.c
> > > @@ -3178,8 +3178,8 @@ static int btrfs_extent_same(struct inode *src, u64 
> > > loff, u64 olen,
> > >  * locking. We use an array for the page pointers. Size of the 
> > > array is
> > >  * bounded by len, which is in turn bounded by 
> > > BTRFS_MAX_DEDUPE_LEN.
> > >  */
> > > -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), 
> > > GFP_KERNEL);
> > > -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), 
> > > GFP_KERNEL);
> > > +   cmp.src_pages = kvzalloc(num_pages, sizeof(struct page *), 
> > > GFP_KERNEL);
> > > +   cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *), 
> > > GFP_KERNEL);
> > 
> > Kvzalloc should take 2 parameters and not 3.
> 
> And the right function is kvmalloc_array.
> 
> > Also, aren't the corresponding kvfree() calls missing?
> 
> Yes, thanks for catching it. The updated version:
> 
> From: David Sterba 
> Subject: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data
> 
> The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> arrays can be 32KiB large. To avoid allocation failures due to
> fragmented memory, use the allocation with fallback to vmalloc.
> 
> Signed-off-by: David Sterba 
> ---
>  fs/btrfs/ioctl.c | 16 +---
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index b572e38b4b64..4fcfa05ed960 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src, u64 
> loff, u64 olen,
>* locking. We use an array for the page pointers. Size of the array is
>* bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
>*/
> - cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> - cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> + cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> +GFP_KERNEL);
> + cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> +GFP_KERNEL);

kcalloc() implies __GFP_ZERO, do we need that here?

>   if (!cmp.src_pages || !cmp.dst_pages) {
> - kfree(cmp.src_pages);
> - kfree(cmp.dst_pages);
> - return -ENOMEM;
> + ret = -ENOMEM;
> + goto out_free;
>   }
>  
>   if (same_inode)
> @@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src, u64 
> loff, u64 olen,
>   else
>   btrfs_double_inode_unlock(src, dst);
>  
> - kfree(cmp.src_pages);
> - kfree(cmp.dst_pages);
> +out_free:
> + kvfree(cmp.src_pages);
> + kvfree(cmp.dst_pages);
>  
>   return ret;
>  }
> -- 
> 2.16.2
> 
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Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

2018-05-11 Thread Filipe Manana

On Fri, May 11, 2018 at 5:49 PM, David Sterba  wrote:
> On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote:
>> On Fri, May 11, 2018 at 4:57 PM, David Sterba  wrote:
>> > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
>> > arrays can be 32KiB large. To avoid allocation failures due to
>> > fragmented memory, use the allocation with fallback to vmalloc.
>> >
>> > Signed-off-by: David Sterba 
>> > ---
>> >
>> > This depends on the patches that remove the 16MiB restriction in the
>> > dedupe ioctl, but contextually can be applied to the current code too.
>> >
>> > https://patchwork.kernel.org/patch/10374941/
>> >
>> >  fs/btrfs/ioctl.c | 4 ++--
>> >  1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
>> > index b572e38b4b64..a7f517009cd7 100644
>> > --- a/fs/btrfs/ioctl.c
>> > +++ b/fs/btrfs/ioctl.c
>> > @@ -3178,8 +3178,8 @@ static int btrfs_extent_same(struct inode *src, u64 
>> > loff, u64 olen,
>> >  * locking. We use an array for the page pointers. Size of the 
>> > array is
>> >  * bounded by len, which is in turn bounded by 
>> > BTRFS_MAX_DEDUPE_LEN.
>> >  */
>> > -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), 
>> > GFP_KERNEL);
>> > -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), 
>> > GFP_KERNEL);
>> > +   cmp.src_pages = kvzalloc(num_pages, sizeof(struct page *), 
>> > GFP_KERNEL);
>> > +   cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *), 
>> > GFP_KERNEL);
>>
>> Kvzalloc should take 2 parameters and not 3.
>
> And the right function is kvmalloc_array.
>
>> Also, aren't the corresponding kvfree() calls missing?
>
> Yes, thanks for catching it. The updated version:
>
> From: David Sterba 
> Subject: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data
>
> The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> arrays can be 32KiB large. To avoid allocation failures due to
> fragmented memory, use the allocation with fallback to vmalloc.
>
> Signed-off-by: David Sterba 
> ---
>  fs/btrfs/ioctl.c | 16 +---
>  1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index b572e38b4b64..4fcfa05ed960 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src, u64 
> loff, u64 olen,
>  * locking. We use an array for the page pointers. Size of the array 
> is
>  * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
>  */
> -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> +   cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> +  GFP_KERNEL);
> +   cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
> +  GFP_KERNEL);
> if (!cmp.src_pages || !cmp.dst_pages) {
> -   kfree(cmp.src_pages);
> -   kfree(cmp.dst_pages);
> -   return -ENOMEM;
> +   ret = -ENOMEM;
> +   goto out_free;
> }
>
> if (same_inode)
> @@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src, u64 
> loff, u64 olen,
> else
> btrfs_double_inode_unlock(src, dst);
>
> -   kfree(cmp.src_pages);
> -   kfree(cmp.dst_pages);
> +out_free:
> +   kvfree(cmp.src_pages);
> +   kvfree(cmp.dst_pages);

kvfree() missing at btrfs_cmp_data_free() too.

>
> return ret;
>  }
> --
> 2.16.2
>



-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”
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Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

2018-05-11 Thread David Sterba

On Fri, May 11, 2018 at 05:25:50PM +0100, Filipe Manana wrote:
> On Fri, May 11, 2018 at 4:57 PM, David Sterba  wrote:
> > The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> > arrays can be 32KiB large. To avoid allocation failures due to
> > fragmented memory, use the allocation with fallback to vmalloc.
> >
> > Signed-off-by: David Sterba 
> > ---
> >
> > This depends on the patches that remove the 16MiB restriction in the
> > dedupe ioctl, but contextually can be applied to the current code too.
> >
> > https://patchwork.kernel.org/patch/10374941/
> >
> >  fs/btrfs/ioctl.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > index b572e38b4b64..a7f517009cd7 100644
> > --- a/fs/btrfs/ioctl.c
> > +++ b/fs/btrfs/ioctl.c
> > @@ -3178,8 +3178,8 @@ static int btrfs_extent_same(struct inode *src, u64 
> > loff, u64 olen,
> >  * locking. We use an array for the page pointers. Size of the 
> > array is
> >  * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
> >  */
> > -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), 
> > GFP_KERNEL);
> > -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), 
> > GFP_KERNEL);
> > +   cmp.src_pages = kvzalloc(num_pages, sizeof(struct page *), 
> > GFP_KERNEL);
> > +   cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *), 
> > GFP_KERNEL);
> 
> Kvzalloc should take 2 parameters and not 3.

And the right function is kvmalloc_array.

> Also, aren't the corresponding kvfree() calls missing?

Yes, thanks for catching it. The updated version:

From: David Sterba 
Subject: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
arrays can be 32KiB large. To avoid allocation failures due to
fragmented memory, use the allocation with fallback to vmalloc.

Signed-off-by: David Sterba 
---
 fs/btrfs/ioctl.c | 16 +---
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b572e38b4b64..4fcfa05ed960 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3178,12 +3178,13 @@ static int btrfs_extent_same(struct inode *src, u64 
loff, u64 olen,
 * locking. We use an array for the page pointers. Size of the array is
 * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
 */
-   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
-   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
+   cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
+  GFP_KERNEL);
+   cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
+  GFP_KERNEL);
if (!cmp.src_pages || !cmp.dst_pages) {
-   kfree(cmp.src_pages);
-   kfree(cmp.dst_pages);
-   return -ENOMEM;
+   ret = -ENOMEM;
+   goto out_free;
}
 
if (same_inode)
@@ -3211,8 +3212,9 @@ static int btrfs_extent_same(struct inode *src, u64 loff, 
u64 olen,
else
btrfs_double_inode_unlock(src, dst);
 
-   kfree(cmp.src_pages);
-   kfree(cmp.dst_pages);
+out_free:
+   kvfree(cmp.src_pages);
+   kvfree(cmp.dst_pages);
 
return ret;
 }
-- 
2.16.2

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Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

2018-05-11 Thread Filipe Manana

On Fri, May 11, 2018 at 4:57 PM, David Sterba  wrote:
> The dedupe range is 16 MiB, with 4KiB pages and 8 byte pointers, the
> arrays can be 32KiB large. To avoid allocation failures due to
> fragmented memory, use the allocation with fallback to vmalloc.
>
> Signed-off-by: David Sterba 
> ---
>
> This depends on the patches that remove the 16MiB restriction in the
> dedupe ioctl, but contextually can be applied to the current code too.
>
> https://patchwork.kernel.org/patch/10374941/
>
>  fs/btrfs/ioctl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index b572e38b4b64..a7f517009cd7 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3178,8 +3178,8 @@ static int btrfs_extent_same(struct inode *src, u64 
> loff, u64 olen,
>  * locking. We use an array for the page pointers. Size of the array 
> is
>  * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
>  */
> -   cmp.src_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> -   cmp.dst_pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
> +   cmp.src_pages = kvzalloc(num_pages, sizeof(struct page *), 
> GFP_KERNEL);
> +   cmp.dst_pages = kvzalloc(num_pages, sizeof(struct page *), 
> GFP_KERNEL);

Kvzalloc should take 2 parameters and not 3.
Also, aren't the corresponding kvfree() calls missing?

> if (!cmp.src_pages || !cmp.dst_pages) {
> kfree(cmp.src_pages);
> kfree(cmp.dst_pages);
> --
> 2.16.2
>
> --
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> the body of a message to majord...@vger.kernel.org
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-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”
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Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

Re: [PATCH] btrfs: use kvzalloc for EXTENT_SAME temporary data

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