Re: [PATCH v2] f2fs: initialize ino_entry_info before checkpoint load

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 06/22, Chao Yu wrote:
> On 6/21/26 16:18, Deepanshu Kartikey wrote:
> > On Sun, May 10, 2026 at 9:53 AM Deepanshu Kartikey
> > <kartikey406@gmail.com> wrote:
> > > 
> > > When f2fs_get_valid_checkpoint() fails during mount (e.g. due to an
> > > invalid checkpoint CRC on a malformed image), f2fs_fill_super() takes
> > > an error path that eventually calls iput() on the root inode. This
> > > invokes f2fs_drop_inode() -> f2fs_exist_written_data(), which acquires
> > > sbi->im[]->ino_lock. However, f2fs_init_ino_entry_info() has not run
> > > yet at this point, so the spinlock is uninitialized and lockdep
> > > complains:
> > > 
> > >    F2FS-fs (loop0): invalid crc value
> > >    F2FS-fs (loop0): Failed to get valid F2FS checkpoint
> > >    INFO: trying to register non-static key.
> > >    The code is fine but needs lockdep annotation, or maybe
> > >    you didn't initialize this object before use?
> > >    ...
> > >     f2fs_exist_written_data+0x53/0x90 fs/f2fs/checkpoint.c:787
> > >     f2fs_drop_inode+0xda/0xbf0 fs/f2fs/super.c:1852
> > >     iput+0x651/0xe80 fs/inode.c:2009
> > >     f2fs_fill_super+0x6047/0x7850 fs/f2fs/super.c:5461
> > > 
> > > Move f2fs_init_ino_entry_info() to before f2fs_get_valid_checkpoint()
> > > so that sbi->im[] is always fully initialized before any error path
> > > can trigger iput() -> f2fs_drop_inode(). The init function only
> > > depends on raw superblock fields (BLKS_PER_SEG, F2FS_CP_PACKS,
> > > NR_CURSEG_PERSIST_TYPE, __cp_payload), which are populated well
> > > before checkpoint load, so the move is safe.
> > > 
> > > Fixes: 3063c80776e3 ("f2fs: another way to set large folio by remembering inode number")
> > > Cc: stable@kernel.org
> > > Reported-by: syzbot+eec8f2693d71386bd600@syzkaller.appspotmail.com
> > > Closes: https://syzkaller.appspot.com/bug?extid=eec8f2693d71386bd600
> > > Tested-by: syzbot+eec8f2693d71386bd600@syzkaller.appspotmail.com
> > > Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
> > > ---
> > > Changes in v2:
> > >   - Add Fixes: tag (suggested by Chao Yu)
> > >   - Add Cc: stable@kernel.org
> > > ---
> > >   fs/f2fs/super.c | 9 +++++++--
> > >   1 file changed, 7 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > > index c6afdbd6e1cd..6a231a5b0d62 100644
> > > --- a/fs/f2fs/super.c
> > > +++ b/fs/f2fs/super.c
> > > @@ -5140,6 +5140,13 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
> > >                  goto free_page_array_cache;
> > >          }
> > > 
> > > +       /*
> > > +        * Initialize ino entry info early so f2fs_drop_inode ->
> > > +        * f2fs_exist_written_data can safely take im->ino_lock if mount
> > > +        * fails after this point and triggers iput on cleanup.
> > > +        */
> > > +       f2fs_init_ino_entry_info(sbi);
> > > +
> > >          err = f2fs_get_valid_checkpoint(sbi);
> > >          if (err) {
> > >                  f2fs_err(sbi, "Failed to get valid F2FS checkpoint");
> > > @@ -5184,8 +5191,6 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
> > > 
> > >          f2fs_init_extent_cache_info(sbi);
> > > 
> > > -       f2fs_init_ino_entry_info(sbi);
> > > -
> > >          f2fs_init_fsync_node_info(sbi);
> > > 
> > >          /* setup checkpoint request control and start checkpoint issue thread */
> > > --
> > > 2.43.0
> > > 
> > 
> > Hi Chao,
> > 
> > Please let me know the status of this patch. This is already "Reviewed-by:" you.
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev-test&id=065a6f8cd23a9297b543dcec913feb3cb787a25e
> 
> It was merged, however, I think it should be reverted because commit 3063c80776e3
> ("f2fs: another way to set large folio by remembering inode number") was removed
> from dev branch, we won't call f2fs_exist_written_data() from f2fs_drop_inode().

Thanks for heads-up. Let me drop this from -dev as emergency call, since the
problemetic patch was not landed at all.

> 
> Thanks,
> 
> > 
> > Please let me know if anything needed from my side.
> > 
> > Thanks
> > 
> > Deepanshu Kartikey
>