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 3003419DF7D for ; Wed, 26 Feb 2025 03:28:43 +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=1740540524; cv=none; b=HDXBxgjyBuz+TmqO/YDVPMpuDHuuHj0P2fx8R+6JmP2f8oAwSuqSsgGVDVnkH5D2/267sqtvI+SsjOuKMCL4LlYt14SsBJCS6YgEO7fqTiO99mljfWIyvzbMQLoeZW8KxKQaAaCenGdAVQGGVt9CiGLcjt2EiARSydmK1VKepuA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740540524; c=relaxed/simple; bh=CNXe5JTTkaXdkY+L1+O2OGLVKOWM894k4Ha5Rt/GRE0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Rp2gow0180fK9vMZCb7DDEC4KOE5rodRKkL8cVivi7CvRqG/fu8hzBa8p2lX6l+uJcqVX9W4fy/LLF/U4cgMIIRyij2VFSwsUB6KwnaaXZGQJ1J40foxZJiLvQ8lbKkuQE3M1EtCew4v8CGbJzwtszq/DkzkczcrwNub7UfomGQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IFy2RB0Q; 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="IFy2RB0Q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71B4DC4CED6; Wed, 26 Feb 2025 03:28:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740540523; bh=CNXe5JTTkaXdkY+L1+O2OGLVKOWM894k4Ha5Rt/GRE0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IFy2RB0QfmHKL04GKVvKs6VZUepp7aVr3t4e4GPjvW82dAw8pNwcZRaIAx9atMH3b 7/VHEKnQ0JDRQeN0OIJYswNQf9UZowyf1VdWvjPj6zuWVKrnmFao8w5txZRROpsucW djSfmvpI05kns2mFp6fNiCdhgBWJdr/CBsUCQphC8yee7B/ud8SYkOP/hH2j3eVK3j CkhRdtxh4FPURnXWNqQ3QYHrt8XBoaB/Mfp7v+93RixgedUuyP4HOPppKNSW85RpEc o4kIBbVcb+WDWOFHP1S4KV+jhWhEBRfMp8IMVrhH5SmWvWem8osHXRI0YtutYZ0Y/y l8YqlnGcux2ZA== Date: Wed, 26 Feb 2025 03:28:41 +0000 From: Jaegeuk Kim To: Chao Yu Cc: 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 Message-ID: References: <20250212072742.977248-1-chao@kernel.org> <666e62d1-3446-485e-bac9-0cc8089b04de@kernel.org> <5f390129-1b93-42d2-8db7-276c370db90f@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f390129-1b93-42d2-8db7-276c370db90f@kernel.org> 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? > > --- > 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 > >