On 2/14/25 01:38, Jaegeuk Kim wrote: > On 02/13, Chao Yu wrote: >> On 2/13/25 00:47, Jaegeuk Kim wrote: >>> On 02/12, Chao Yu wrote: >>>> From: Leo Stone <leocst...@gmail.com> >>>> >>>> The syzbot reproducer mounts a f2fs image, then tries to unlink an >>>> existing file. However, the unlinked file already has a link count of 0 >>>> when it is read for the first time in do_read_inode(). >>>> >>>> Add a check to sanity_check_inode() for i_nlink == 0. >>>> >>>> [Chao Yu: rebase the code and fix orphan inode recovery issue] >>>> Reported-by: syzbot+b01a36acd7007e273...@syzkaller.appspotmail.com >>>> Closes: https://syzkaller.appspot.com/bug?extid=b01a36acd7007e273a83 >>>> Fixes: 39a53e0ce0df ("f2fs: add superblock and major in-memory structure") >>>> Signed-off-by: Leo Stone <leocst...@gmail.com> >>>> Signed-off-by: Chao Yu <c...@kernel.org> >>>> --- >>>> fs/f2fs/checkpoint.c | 4 ++++ >>>> fs/f2fs/f2fs.h | 1 + >>>> fs/f2fs/inode.c | 6 ++++++ >>>> 3 files changed, 11 insertions(+) >>>> >>>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >>>> index bd890738b94d..ada2c548645c 100644 >>>> --- a/fs/f2fs/checkpoint.c >>>> +++ b/fs/f2fs/checkpoint.c >>>> @@ -751,6 +751,8 @@ int f2fs_recover_orphan_inodes(struct f2fs_sb_info >>>> *sbi) >>>> if (is_sbi_flag_set(sbi, SBI_IS_WRITABLE)) >>>> f2fs_info(sbi, "orphan cleanup on readonly fs"); >>>> >>>> + set_sbi_flag(sbi, SBI_ORPHAN_RECOVERY); >>> >>> What about using SBI_POR_DOING? >> >> SBI_POR_DOING will cover most flow of f2fs_fill_super(), I think we can add a >> separated flag just covering f2fs_recover_orphan_inodes(), so that we can >> allow >> iget() of root_inode and all inodes during roll-forward recovery to do sanity >> check nlink w/ zero. What do you think? > > Can we do this sanity check after f2fs_iget in the f2fs_unlink() only?
Sure, we need to cover f2fs_rename() as well, please check this: https://lore.kernel.org/all/67450f9a.050a0220.21d33d.0003....@google.com Thanks, > >> >> Thanks, >> >>> >>>> + >>>> start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi); >>>> orphan_blocks = __start_sum_addr(sbi) - 1 - __cp_payload(sbi); >>>> >>>> @@ -778,9 +780,11 @@ int f2fs_recover_orphan_inodes(struct f2fs_sb_info >>>> *sbi) >>>> } >>>> f2fs_put_page(page, 1); >>>> } >>>> + >>>> /* clear Orphan Flag */ >>>> clear_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG); >>>> out: >>>> + clear_sbi_flag(sbi, SBI_ORPHAN_RECOVERY); >>>> set_sbi_flag(sbi, SBI_IS_RECOVERED); >>>> >>>> return err; >>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>> index 05879c6dc4d6..1c75081c0c14 100644 >>>> --- a/fs/f2fs/f2fs.h >>>> +++ b/fs/f2fs/f2fs.h >>>> @@ -1322,6 +1322,7 @@ enum { >>>> SBI_IS_CLOSE, /* specify unmounting */ >>>> SBI_NEED_FSCK, /* need fsck.f2fs to fix */ >>>> SBI_POR_DOING, /* recovery is doing or not */ >>>> + SBI_ORPHAN_RECOVERY, /* orphan inodes recovery is >>>> doing */ >>>> SBI_NEED_SB_WRITE, /* need to recover superblock */ >>>> SBI_NEED_CP, /* need to checkpoint */ >>>> SBI_IS_SHUTDOWN, /* shutdown by ioctl */ >>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >>>> index d6ad7810df69..02f1b69d03d8 100644 >>>> --- a/fs/f2fs/inode.c >>>> +++ b/fs/f2fs/inode.c >>>> @@ -386,6 +386,12 @@ static bool sanity_check_inode(struct inode *inode, >>>> struct page *node_page) >>>> } >>>> } >>>> >>>> + if (inode->i_nlink == 0 && !is_sbi_flag_set(sbi, SBI_ORPHAN_RECOVERY)) { >>>> + f2fs_warn(sbi, "%s: inode (ino=%lx) has a link count of 0", >>>> + __func__, inode->i_ino); >>>> + return false; >>>> + } >>>> + >>>> return true; >>>> } >>>> >>>> -- >>>> 2.48.1.502.g6dc24dfdaf-goog _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
