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 55E2D78F35 for ; Fri, 14 Feb 2025 01:44:05 +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=1739497446; cv=none; b=fmKyZtinWZjRGC40o/qKD5zcrC3RUqzsda8NxT887+WX5f4ykZ8hLnP3K8aL8Jqvfcf82YKF+5ouKHSUhwQWducaFmtcYgBFCtRoC+oSVnHNuvC51chQXsrMU8y7dpgnnO5q7KznxZHqZhpliqKXE0SJAKiohFr/9XS4TPtt3Ys= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739497446; c=relaxed/simple; bh=srHnIBrfKhu2UDIBKLlSsyLyAHlxsbiKD5o0g6U58jQ=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=lKw9tflJs4ULmSC6G02rh7ko1fX20zebPRSrA0F7gHndUoK9jzRDT5SaV8DCQ8FFXFg8dF0q4H5ytzr+0DQ9jiu7sB+anhzVmZdsKwljX+Wrp5usa7gglDpDLt9pf25U7pRJf3sXJu9YdEsL75bJi/cN7MFVolPjqg/ZAHxJaEo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g7NozJMI; 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="g7NozJMI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BDA5C4CED1; Fri, 14 Feb 2025 01:44:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739497445; bh=srHnIBrfKhu2UDIBKLlSsyLyAHlxsbiKD5o0g6U58jQ=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=g7NozJMIgQj6eZmzKYVzMg+NXJPGqyPPZZeGlC/8BwP+Y5h0N+LEgXhx7GDU/gQuw zq7wyv4Z1VH9VApf6TEMpxqsR662ZwDDbXpx9GAIiUjXA8P0E/056rheg/bA4Hmt66 +Gnd6Z8n1hP1HBVRo5FYWQKkkdgAKSeBgxWwSObnHJRLuN9tON1XiFt8HqDKP5JCNf qQBTEopNfEVQU2LU7ZHxt+AhP8LKZmSc+tdYe/Au6jIVvq19foaUB+kB+IaUHIXUMm Kkva7r0Kg6b+wr/LqoEJf/7XdPcpfSEPEsI2O254oDBfEXphdQTPbsAy75RbyK2wfx pFvYsL0N3O3xQ== Message-ID: <666e62d1-3446-485e-bac9-0cc8089b04de@kernel.org> Date: Fri, 14 Feb 2025 09:44:02 +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 2/14/25 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 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