Re: [PATCH blktests 0/3] test and handle concurrent IO scheduler switching

[Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>]

On Jul 26, 2026 / 14:32, Shin'ichiro Kawasaki wrote:
> Until the recent kernel commit 4ff58d6bc9dd ("block: serialize elevator
> changes for the same queue using a writer lock") concurrent writes to
> the sysfs file queue/scheduler caused KASAN failures [1]. The first
> patch of this series adds the regression test case for the fix.
> 
> After the kernel commit, writes to the file queue/scheduler can return
> -EBUSY. This is rare but can happen when udevd writes to the file at
> exactly the same timing as blktests test cases, and it results in
> unexpected test failures. The other two patches in this series handle
> -EBUSY and avoid the failures.
> 
> [1] https://lore.kernel.org/linux-block/20260626004221.711326-1-shinichiro.kawasaki@wdc.com/
> 
> Shin'ichiro Kawasaki (3):
>   block: add test for concurrent IO scheduler switching
>   check: introduce _write_queue_sched() to repeat queue/scheduler writes
>   common, block/{015,020,021,027,040}, zbd/012: use _write_queue_sched()

FYI, I applied the series. As to the first patch, I renumbered the test case
from block/045 to block/047.