Re: [PATCH v2 0/5] More unit test for mballoc

[Kemeng Shi]

on 2/26/2024 12:07 AM, Guenter Roeck wrote:
> On Wed, Jan 03, 2024 at 06:48:55PM +0800, Kemeng Shi wrote:
>> This series covers more function to mark on-disk bitmap. Besides, some
>> code which is relevant to buddy cache is also tested.
>> Before more work is done, I want to be sure I'm not on a wrong
>> direction!
>>
>> v1->v2:
>> -Fix unused variable warning which is reported at
>> https://lore.kernel.org/lkml/202311260042.kMxL6DnL-lkp@xxxxxxxxx/T/
>>
> 
> With this patch series in linux-text, and with various debug options
> enabled, unit tests for ext4 fail widely and result in crashes.
> 
> [    4.798582]         # Subtest: test_new_blocks_simple
> [    4.803166] BUG: key 00000000000000a8 has not been registered!
> [    4.803443] ------------[ cut here ]------------
> ILLOPC: ffffffff9050cbf4: 0f 0b
> [    4.803521] DEBUG_LOCKS_WARN_ON(1)
> [    4.803720] WARNING: CPU: 0 PID: 154 at kernel/locking/lockdep.c:4895 lockdep_init_map_type+0x224/0x250
Not sure how this is triggerred.
> ...
> [    4.833277]         # Subtest: test_mb_mark_used
> [    4.835875] ------------[ cut here ]------------
> [    4.836055] kernel BUG at fs/ext4/mballoc.c:2053!
Internal functions mb_mark_used assumes group lock is held but unit
test code doesn't acquire it as there is no concurrent block
allocation/free in test code. Will add lock in unit test to fix this.
> 
> Guenter
> 
Hi Guenter, thanks for test and report this. I will appreciate it if
you could tell me how to reproduce this as I need to debug the first
issue and verify the fix. Thanks!