Re: [RFC PATCH] f2fs: remove some redundant flow about FI_ATOMIC_DIRTIED

[Zhiguo Niu]

Chao Yu <chao@xxxxxxxxxx> 于2025年3月26日周三 17:26写道：
>
> On 3/26/25 16:46, Zhiguo Niu wrote:
> > Commit fccaa81de87e ("f2fs: prevent atomic file from being dirtied before commit")
> > adds the processing of FI_ATOMIC_DIRTIED in the following two positions,
> > [1]
> > f2fs_commit_atomic_write
> >  - __f2fs_commit_atomic_write
> >   - sbi->committed_atomic_block += fi->atomic_write_cnt;
> >   - set_inode_flag(inode, FI_ATOMIC_COMMITTED);
> >   - if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
> >   -    clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
> >   -    f2fs_mark_inode_dirty_sync(inode, true);
> >   - }
> > [2]
> > f2fs_abort_atomic_write
> >   - if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
> >   -    clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
> >   -    f2fs_mark_inode_dirty_sync(inode, true);
> >   - }
> >
> > but [1] seems to be redundant:
> > The atomic file flag FI_ATOMIC_FILE is still set here, so f2fs_mark_inode_dirty_sync
> > still does not set the dirty state to vfs. If FI_ATOMIC_DIRTIED was originally set
> > when atomic file is committing, then FI_ATOMIC_DIRTIED is just cleared here, and
> > then do the repeating action of setting FI_ATOMIC_DIRTIED?
> > So is it enough to do this only in [2]?
>
> Hi Zhiguo,
>
> I checked the code again, finally, I got this, could you please take
> a look?
>
> Ping Daeho as well.
>
> Subject: [PATCH] f2fs: fix to set atomic write status more clear
>
> 1. After we start atomic write in a database file, before committing
> all data, we'd better not set inode w/ vfs dirty status to avoid
> redundant updates, instead, we only set inode w/ atomic dirty status.
>
> 2. After we commit all data, before committing metadata, we need to
> clear atomic dirty status, and set vfs dirty status to allow vfs flush
> dirty inode.
>
Hi Chao,
these looks more clear.
> Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
> ---
>  fs/f2fs/inode.c   |  4 +++-
>  fs/f2fs/segment.c | 10 ++++++----
>  fs/f2fs/super.c   |  4 +++-
>  3 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 5c8634eaef7b..f5991e8751b9 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -34,7 +34,9 @@ void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync)
>         if (f2fs_inode_dirtied(inode, sync))
>                 return;
>
> -       if (f2fs_is_atomic_file(inode))
> +       /* only atomic file w/ FI_ATOMIC_COMMITTED can be set vfs dirty */
> +       if (f2fs_is_atomic_file(inode) &&
> +                       !is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
>                 return;
>
>         mark_inode_dirty_sync(inode);
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index dc360b4b0569..28659a71891a 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -376,10 +376,12 @@ static int __f2fs_commit_atomic_write(struct inode *inode)
>         } else {
>                 sbi->committed_atomic_block += fi->atomic_write_cnt;
>                 set_inode_flag(inode, FI_ATOMIC_COMMITTED);
> -               if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
> -                       clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
> -                       f2fs_mark_inode_dirty_sync(inode, true);
> -               }
> +
> +               f2fs_bug_on(sbi, !is_inode_flag_set(inode, FI_ATOMIC_DIRTIED));
but FI_ATOMIC_DIRTIED may  not be set when atomic file is committing?
thanks!
> +
> +               /* clear atomic dirty status and set vfs dirty status */
> +               clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
> +               f2fs_mark_inode_dirty_sync(inode, true);
>         }
>
>         __complete_revoke_list(inode, &revoke_list, ret ? true : false);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 9a42a1323f42..a5cc9f6ee16a 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1532,7 +1532,9 @@ int f2fs_inode_dirtied(struct inode *inode, bool sync)
>         }
>         spin_unlock(&sbi->inode_lock[DIRTY_META]);
>
> -       if (!ret && f2fs_is_atomic_file(inode))
> +       /* if atomic write is not committed, set inode w/ atomic dirty */
> +       if (!ret && f2fs_is_atomic_file(inode) &&
> +                       !is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
>                 set_inode_flag(inode, FI_ATOMIC_DIRTIED);
>
>         return ret;
> --
> 2.48.1
>
>
> >
> > Cc: Daeho Jeong <daehojeong@xxxxxxxxxx>
> > Fixes: fccaa81de87e ("f2fs: prevent atomic file from being dirtied before commit")
> > Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> > ---
> >  fs/f2fs/segment.c | 4 ----
> >  1 file changed, 4 deletions(-)
> >
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index 396ef71..d4ea3af 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -376,10 +376,6 @@ static int __f2fs_commit_atomic_write(struct inode *inode)
> >       } else {
> >               sbi->committed_atomic_block += fi->atomic_write_cnt;
> >               set_inode_flag(inode, FI_ATOMIC_COMMITTED);
> > -             if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
> > -                     clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
> > -                     f2fs_mark_inode_dirty_sync(inode, true);
> > -             }
> >       }
> >
> >       __complete_revoke_list(inode, &revoke_list, ret ? true : false);
>