linux-kernel - Re: [PATCH v1] f2fs: Fix discard bug on zoned block devices with 2MiB zone size

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 24 Mar 2023 09:52:25 +0800
From:   Chao Yu <chao@...nel.org>
To:     Jaegeuk Kim <jaegeuk@...nel.org>
Cc:     yonggil.song@...sung.com,
        "linux-f2fs-devel@...ts.sourceforge.net" 
        <linux-f2fs-devel@...ts.sourceforge.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1] f2fs: Fix discard bug on zoned block devices with 2MiB
 zone size

On 2023/3/24 6:03, Jaegeuk Kim wrote:
> On 03/23, Chao Yu wrote:
>> On 2023/3/13 17:48, Yonggil Song wrote:
>>> When using f2fs on a zoned block device with 2MiB zone size, IO errors
>>> occurs because f2fs tries to write data to a zone that has not been reset.
>>>
>>> The cause is that f2fs tries to discard multiple zones at once. This is
>>> caused by a condition in f2fs_clear_prefree_segments that does not check
>>> for zoned block devices when setting the discard range. This leads to
>>> invalid reset commands and write pointer mismatches.
>>>
>>> This patch fixes the zoned block device with 2MiB zone size to reset one
>>> zone at a time.
>>>
>>> Signed-off-by: Yonggil Song <yonggil.song@...sung.com>
>>> ---
>>>    fs/f2fs/segment.c | 3 ++-
>>>    1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index acf3d3fa4363..2b6cb6df623b 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -1953,7 +1953,8 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
>>>    					(end - 1) <= cpc->trim_end)
>>>    				continue;
>>> -		if (!f2fs_lfs_mode(sbi) || !__is_large_section(sbi)) {
>>> +		if (!f2fs_sb_has_blkzoned(sbi) &&
>>
>> Could you please add one line comment here for this change?
> 
> This was merged in -dev a while ago. I don't think this would be critical
> to rebase it again.

Yes, it's not critical, fine to me.

Thanks,

> 
>>
>> Otherwise it looks good to me.
>>
>> Thanks,
>>
>>> +		    (!f2fs_lfs_mode(sbi) || !__is_large_section(sbi))) {
>>>    			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
>>>    				(end - start) << sbi->log_blocks_per_seg);
>>>    			continue;