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 7A6D5184F for ; Thu, 13 Feb 2025 02:00:53 +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=1739412053; cv=none; b=uuKfnJBpBRMq3A4qke0WQhFTBLASU/bPZ2G3PfoBN7qQ9ualVsBBRQ15bh5mhOf3VSY2838x7pBK7jCJ0j4Jo1798HTTuYN8/W0d4QMvJYQAX2LIZ5w/2Enq4p5MSY5bUA2WUgFeeC6xz/KxMhfvUR2HbBp9qFv7qtvBk1bOMgQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739412053; c=relaxed/simple; bh=i+aNMjx3f4xLDQq1iZy53Xav0/SNZ98Rv14350OTH1k=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=nGeDQflHg2o1MxI4L4xzUdwXcwQkBEtoVuW/4djvvMlKksU+dks8axLZugWhi+jrugsZJgvIeoXgJZZbFFOcksNbpQqEzBMOoAO2/DQoP5cQ2TESD40cN/Nzhovuj10/zgWku1T/iJLbqoo+UIT7B2y7STeRvWpZ+ZW6S2KVlOQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DA331jt9; 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="DA331jt9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7643C4CEDF; Thu, 13 Feb 2025 02:00:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739412052; bh=i+aNMjx3f4xLDQq1iZy53Xav0/SNZ98Rv14350OTH1k=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=DA331jt9ZL+V7DrMQ+SQRrgGrus7xFu4aC4G/oLcnkd97yxVW8s6YEkLvMtpmxXMo RhNBFFsyoDsgqIz9pHvtfcr1qudbQq+MMqKY5G7Ep6E/1IO7MdxAfw81aAyslQrSzG ZAazCs4QLmn+iRSU/LDCwMHPniy7hE3WWfEDSl4258mQRNoe8gvrcZlhCkYZx9X+r9 fLr2eBK8uWFeS7RiInvWEvNiizxjbdUCmu8vuzBMy7RaPfuoUbDRK8v+0P7cwp3yh7 I/68E5iixzoihDwDB8eoVR+P6L7cWygaBE1riF0fYJbuGoiW2ue5sugoZq6XBTJCW5 //ZdfKb8BuSBA== Message-ID: Date: Thu, 13 Feb 2025 10:00:49 +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> Content-Language: en-US From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 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? 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