On 07/31, Chao Yu wrote:
> On 2019/7/31 2:02, Jaegeuk Kim wrote:
> > On 07/29, Chao Yu wrote:
> >> On 2019/7/29 13:57, Jaegeuk Kim wrote:
> >>> On 07/23, Chao Yu wrote:
> >>>> On 2019/7/23 10:36, Jaegeuk Kim wrote:
> >>>>> On 07/19, Chao Yu wrote:
> >>>>>> Pinning a file is heavy, because skipping pinned files make GC
> >>>>>> running with heavy load or no effect.
> >>>>>
> >>>>> Pinned file is a part of NOCOW files, so I don't think we can simply
> >>>>> drop it
> >>>>> for backward compatibility.
> >>>>
> >>>> Yes,
> >>>>
> >>>> But what I concerned is that pin file is too heavy, so in order to
> >>>> satisfy below
> >>>> demand, how about introducing pin_file_2 flag to triggering IPU only
> >>>> during
> >>>> flush/writeback.
> >>>
> >>> That can be done by cold files?
> >>
> >> Then it may inherit property of cold type file, e.g. a) goes into cold
> >> area; b)
> >> update with very low frequency.
> >>
> >> Actually pin_file_2 could be used by db-wal/log file, which are updated
> >> frequently, and should go to hot/warm area, it does not match above two
> >> property.
> >
> > How about considering another name like "IPU-only mode"?
> >
> > fallocate write Flag GC
> > Pin_file: preallocate IPU FS_NOCOW_FL Not allowed
> > IPU_file: Not preallocate IPU N/A Default by temperature
>
> One question, do we need preallocate physical block address for IPU_file as
> Pin_file? since it can enhance db file's sequential read performance, not
> sure,
> db can handle random data in preallocated blocks.
db file will do atomic writes, which can not be used with this. -wal may be able
to preallocate blocks, but it can eat disk space unnecessarily.
>
> Other behaviors looks good to me. :)
>
> I plan to use last bit in inode.i_inline to store this flag.
Why not using i_flag like FS_NOCOW_FL?
>
> > Cold_file: Not preallocate IPU N/A Move in cold area
> > Hot_file: Not preallocate IPU/OPU N/A Move in hot area
>
> Should hot file be gced to hot area? That would mix new hot data with old
> 'hot'
> data which actually become cold.
But, user explicitly specified this is hot.
>
> Thanks,
>
> >
> >>
> >> Thank,
> >>
> >>>
> >>>>
> >>>>>
> >>>>>>
> >>>>>> So that this patch propose to separate nocow and pinfile semantics:
> >>>>>> - NOCoW flag can only be set on regular file.
> >>>>>> - NOCoW file will only trigger IPU at common writeback/flush.
> >>>>>> - NOCow file will do OPU during GC.
> >>>>>>
> >>>>>> For the demand of 1) avoid fragment of file's physical block and
> >>>>>> 2) userspace don't care about file's specific physical address,
> >>>>>> tagging file as NOCoW will be cheaper than pinned one.
> >>>>
> >>>> ^^^
> >>>>
> >>>> Thanks,
> >>>>
> >>>>>>
> >>>>>> Signed-off-by: Chao Yu <yuch...@huawei.com>
> >>>>>> ---
> >>>>>> v2:
> >>>>>> - rebase code to fix compile error.
> >>>>>> fs/f2fs/data.c | 3 ++-
> >>>>>> fs/f2fs/f2fs.h | 1 +
> >>>>>> fs/f2fs/file.c | 22 +++++++++++++++++++---
> >>>>>> 3 files changed, 22 insertions(+), 4 deletions(-)
> >>>>>>
> >>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> >>>>>> index a2a28bb269bf..15fb8954c363 100644
> >>>>>> --- a/fs/f2fs/data.c
> >>>>>> +++ b/fs/f2fs/data.c
> >>>>>> @@ -1884,7 +1884,8 @@ static inline bool
> >>>>>> check_inplace_update_policy(struct inode *inode,
> >>>>>>
> >>>>>> bool f2fs_should_update_inplace(struct inode *inode, struct
> >>>>>> f2fs_io_info *fio)
> >>>>>> {
> >>>>>> - if (f2fs_is_pinned_file(inode))
> >>>>>> + if (f2fs_is_pinned_file(inode) ||
> >>>>>> + F2FS_I(inode)->i_flags & F2FS_NOCOW_FL)
> >>>>>> return true;
> >>>>>>
> >>>>>> /* if this is cold file, we should overwrite to avoid
> >>>>>> fragmentation */
> >>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >>>>>> index 596ab3e1dd7b..f6c5a3d2e659 100644
> >>>>>> --- a/fs/f2fs/f2fs.h
> >>>>>> +++ b/fs/f2fs/f2fs.h
> >>>>>> @@ -2374,6 +2374,7 @@ static inline void f2fs_change_bit(unsigned int
> >>>>>> nr, char *addr)
> >>>>>> #define F2FS_NOATIME_FL 0x00000080 /* do not
> >>>>>> update atime */
> >>>>>> #define F2FS_INDEX_FL 0x00001000 /* hash-indexed
> >>>>>> directory */
> >>>>>> #define F2FS_DIRSYNC_FL 0x00010000 /* dirsync
> >>>>>> behaviour (directories only) */
> >>>>>> +#define F2FS_NOCOW_FL 0x00800000 /* Do not cow file */
> >>>>>> #define F2FS_PROJINHERIT_FL 0x20000000 /* Create with
> >>>>>> parents projid */
> >>>>>>
> >>>>>> /* Flags that should be inherited by new inodes from their parent. */
> >>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> >>>>>> index 7ca545874060..ae0fec54cac6 100644
> >>>>>> --- a/fs/f2fs/file.c
> >>>>>> +++ b/fs/f2fs/file.c
> >>>>>> @@ -1692,6 +1692,7 @@ static const struct {
> >>>>>> { F2FS_NOATIME_FL, FS_NOATIME_FL },
> >>>>>> { F2FS_INDEX_FL, FS_INDEX_FL },
> >>>>>> { F2FS_DIRSYNC_FL, FS_DIRSYNC_FL },
> >>>>>> + { F2FS_NOCOW_FL, FS_NOCOW_FL },
> >>>>>> { F2FS_PROJINHERIT_FL, FS_PROJINHERIT_FL },
> >>>>>> };
> >>>>>>
> >>>>>> @@ -1715,7 +1716,8 @@ static const struct {
> >>>>>> FS_NODUMP_FL | \
> >>>>>> FS_NOATIME_FL | \
> >>>>>> FS_DIRSYNC_FL | \
> >>>>>> - FS_PROJINHERIT_FL)
> >>>>>> + FS_PROJINHERIT_FL | \
> >>>>>> + FS_NOCOW_FL)
> >>>>>>
> >>>>>> /* Convert f2fs on-disk i_flags to FS_IOC_{GET,SET}FLAGS flags */
> >>>>>> static inline u32 f2fs_iflags_to_fsflags(u32 iflags)
> >>>>>> @@ -1753,8 +1755,6 @@ static int f2fs_ioc_getflags(struct file *filp,
> >>>>>> unsigned long arg)
> >>>>>> fsflags |= FS_ENCRYPT_FL;
> >>>>>> if (f2fs_has_inline_data(inode) ||
> >>>>>> f2fs_has_inline_dentry(inode))
> >>>>>> fsflags |= FS_INLINE_DATA_FL;
> >>>>>> - if (is_inode_flag_set(inode, FI_PIN_FILE))
> >>>>>> - fsflags |= FS_NOCOW_FL;
> >>>>>>
> >>>>>> fsflags &= F2FS_GETTABLE_FS_FL;
> >>>>>>
> >>>>>> @@ -1794,6 +1794,22 @@ static int f2fs_ioc_setflags(struct file *filp,
> >>>>>> unsigned long arg)
> >>>>>> if (ret)
> >>>>>> goto out;
> >>>>>>
> >>>>>> + if ((fsflags ^ old_fsflags) & FS_NOCOW_FL) {
> >>>>>> + if (!S_ISREG(inode->i_mode)) {
> >>>>>> + ret = -EINVAL;
> >>>>>> + goto out;
> >>>>>> + }
> >>>>>> +
> >>>>>> + if (f2fs_should_update_outplace(inode, NULL)) {
> >>>>>> + ret = -EINVAL;
> >>>>>> + goto out;
> >>>>>> + }
> >>>>>> +
> >>>>>> + ret = f2fs_convert_inline_inode(inode);
> >>>>>> + if (ret)
> >>>>>> + goto out;
> >>>>>> + }
> >>>>>> +
> >>>>>> ret = f2fs_setflags_common(inode, iflags,
> >>>>>> f2fs_fsflags_to_iflags(F2FS_SETTABLE_FS_FL));
> >>>>>> out:
> >>>>>> --
> >>>>>> 2.18.0.rc1
> >>>>> .
> >>>>>
> >>> .
> >>>
> > .
> >
