From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA1B654782 for ; Fri, 28 Feb 2025 01:49:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740707393; cv=none; b=ARprwfQDEmv4UoqpYGPUumcNvLOiKdAIyYgri2sn+tK353x/b7L/PAbLAwZKd9RpVm2mAvVi1tGi7T2uPsNGCkMr8H8fcNy7yRATVjXtD9YV2xDan2LRTAEqJeE2vjGW4gQ0vQo+kS2i8HMmUZIWqFnf0kmVPm6qWOMx+AvG+XI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740707393; c=relaxed/simple; bh=0VY1TID949UImeVHNR6LSjUTfsDAex3p0YM5P5Y5bYU=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=XhH+EIJ10y3O0OPgHw2DZ4qKM1s8W5WzNoi3IvOi1FFbgSnha1O3ut6HtHOw6YZk5WrpSyaQIRzn2U0+aiZcbR/o8ejYr4gEr/ADHmb9sb/jSUlESPx37xbpTUJmmeZU7pkHzf5TzPk0otZx3OQm27q40aRa9mHbj5mxkC/mkg0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sdg0zqbn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sdg0zqbn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29D70C4CEE6; Fri, 28 Feb 2025 01:49:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740707393; bh=0VY1TID949UImeVHNR6LSjUTfsDAex3p0YM5P5Y5bYU=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=sdg0zqbnp+8QN6rbw/ZOaoY9jHb3UOkxbj7pkTBhX7DEmpVM7tjmrkPBA+MOcP7AP 72OIjtUbA2R3GchYZJS16e5RwVCCDBe6+u9Lq05APQxgBMURPF/cxMDwwoEKX38Slg AJDo/1rSBXFkwXIFN9RAcnn+Fii+csWvtiX+kw9hFl+mHb1ZkhdqPtUysngA8E4rbE K92AcJ7F5jsn5dpCigtBkmV08lcmikzqGLm7V4XMsHAE/0Rc0eyQzQ/lEgC+MQUl6N 8gVDejdYqeM44LGf25cTgdxe4vDfqwoxwn2cKh6ieoO89WcIuROxUyvhgbQ3TNLsUr og3WbEhgdtnBw== Message-ID: Date: Fri, 28 Feb 2025 09:49:55 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Leo Stone , syzbot+b01a36acd7007e273a83@syzkaller.appspotmail.com Subject: Re: [PATCH v4] f2fs: add check for deleted inode To: Jaegeuk Kim References: <20250212072742.977248-1-chao@kernel.org> <666e62d1-3446-485e-bac9-0cc8089b04de@kernel.org> <5f390129-1b93-42d2-8db7-276c370db90f@kernel.org> <7fb3ffcb-4513-45da-8f83-eebe8f5e008b@kernel.org> Content-Language: en-US From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025/2/27 1:15, Jaegeuk Kim wrote: > On 02/26, Chao Yu wrote: >> On 2/26/25 11:28, Jaegeuk Kim wrote: >>> On 02/24, Chao Yu wrote: >>>> On 2/14/25 09:44, Chao Yu wrote: >>>>> 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 >>>>>>>>> >>>>>>>>> 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+b01a36acd7007e273a83@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 >>>>>>>>> Signed-off-by: Chao Yu >>>>>>>>> --- >>>>>>>>> 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.GAE@google.com >>>> >>>> Hi Jaegeuk, >>>> >>>> I'm testing this, seems there is a problem, once we opened an inode that >>>> has zeroed nlink, in f2fs_evict_inode(), the inode and all its data will be >>>> deleted, then leaving its stale dir entry in parent directory. >>>> >>>> What do you think using v4? so that we may has chance to repair it w/ fsck >>>> rather than just deleting it? >>> >>> Do you mean v4 as the below change? >> >> I mean this v4 patch: > > What about checking i_nlink right after f2fs_iget in f2fs_lookup? Fine to me, I've updated in v5. Thanks, > >> >> --- >> 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); >> + >> 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; >> } >> >> Thanks, >> >>> >>>> >>>> --- >>>> fs/f2fs/namei.c | 19 +++++++++++++++++++ >>>> 1 file changed, 19 insertions(+) >>>> >>>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c >>>> index a278c7da8177..949621bc0d07 100644 >>>> --- a/fs/f2fs/namei.c >>>> +++ b/fs/f2fs/namei.c >>>> @@ -547,6 +547,16 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry) >>>> goto fail; >>>> } >>>> >>>> + if (unlikely(S_ISDIR(inode->i_mode) ? >>>> + inode->i_nlink <= 1 : inode->i_nlink == 0)) { >>>> + f2fs_err_ratelimited(sbi, "%s: inode (ino=%lx) has inconsistent nlink: %u, isdir: %d", >>>> + __func__, inode->i_ino, inode->i_nlink, >>>> + S_ISDIR(inode->i_mode)); >>>> + err = -EFSCORRUPTED; >>>> + set_sbi_flag(sbi, SBI_NEED_FSCK); >>>> + goto fail; >>>> + } >>>> + >>>> err = f2fs_dquot_initialize(dir); >>>> if (err) >>>> goto fail; >>>> @@ -968,6 +978,15 @@ static int f2fs_rename(struct mnt_idmap *idmap, struct inode *old_dir, >>>> } >>>> >>>> if (new_inode) { >>>> + if (unlikely(old_is_dir ? >>>> + new_inode->i_nlink <= 1 : new_inode->i_nlink == 0)) { >>>> + f2fs_err_ratelimited(sbi, "%s: inode (ino=%lx) has inconsistent nlink: %u, isdir: %d", >>>> + __func__, new_inode->i_ino, new_inode->i_nlink, >>>> + S_ISDIR(new_inode->i_mode)); >>>> + err = -EFSCORRUPTED; >>>> + set_sbi_flag(sbi, SBI_NEED_FSCK); >>>> + goto out_dir; >>>> + } >>>> >>>> err = -ENOTEMPTY; >>>> if (old_is_dir && !f2fs_empty_dir(new_inode)) >>>> -- >>>> 2.48.1.601.g30ceb7b040-goog >>>> >>>>> >>>>> 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 >>>>>