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?
>
> >
> >>
> >> 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
> > .
> >
