Re: [PATCH RESEND] raid5: fix duplicate checks for rdev->saved_raid_disk

[Jackie Liu <liu.yun@linux.dev>]

Hi, Song.

在 2022/7/17 13:31, Song Liu 写道:
> On Fri, Jul 15, 2022 at 8:11 PM Jackie Liu <liu.yun@linux.dev> wrote:
>>
>> From: Jackie Liu <liuyun01@kylinos.cn>
>>
>> 'first' will always be greater than or equal to 0, it is unnecessary to
>> repeat the 0 check, clean it up.
>>
>> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
> 
> This looks identical to the original version. Which branch is this based on?
> Please rebase on top of md-next branch and resend the patch:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/song/md.git/log/?h=md-next
> 

The md-next branch is lower than the upstream version, v5.19-rc5
adds a patch.

commit 617b365872a247480e9dcd50a32c8d1806b21861
Author: Mikulas Patocka <mpatocka@redhat.com>
Date:   Wed Jun 29 13:40:57 2022 -0400

     dm raid: fix KASAN warning in raid5_add_disks

     There's a KASAN warning in raid5_add_disk when running the LVM 
testsuite.
     The warning happens in the test
     lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the 
warning
     by verifying that rdev->saved_raid_disk is within limits.

     Cc: stable@vger.kernel.org
     Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
     Signed-off-by: Mike Snitzer <snitzer@kernel.org>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ba289411f26f..20e53b167f81 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -8065,6 +8065,7 @@ static int raid5_add_disk(struct mddev *mddev, 
struct md_rdev *rdev)
          */
         if (rdev->saved_raid_disk >= 0 &&
             rdev->saved_raid_disk >= first &&
+           rdev->saved_raid_disk <= last &&
             conf->disks[rdev->saved_raid_disk].rdev == NULL)
                 first = rdev->saved_raid_disk;

...
can you rebase from upstream? Thanks.

--
Jackie

> Thanks,
> Song
> 
>> ---
>>   drivers/md/raid5.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>> index 20e53b167f81..a0b38a0ea9c3 100644
>> --- a/drivers/md/raid5.c
>> +++ b/drivers/md/raid5.c
>> @@ -8063,8 +8063,7 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
>>           * find the disk ... but prefer rdev->saved_raid_disk
>>           * if possible.
>>           */
>> -       if (rdev->saved_raid_disk >= 0 &&
>> -           rdev->saved_raid_disk >= first &&
>> +       if (rdev->saved_raid_disk >= first &&
>>              rdev->saved_raid_disk <= last &&
>>              conf->disks[rdev->saved_raid_disk].rdev == NULL)
>>                  first = rdev->saved_raid_disk;
>> --
>> 2.25.1
>>