Re: [PATCH] md: do not delete safemode_timer in mddev_suspend

[Song Liu]

On Wed, May 8, 2024 at 2:31 AM <linan666@xxxxxxxxxxxxxxx> wrote:
>
> From: Li Nan <linan122@xxxxxxxxxx>
>
> The deletion of safemode_timer in mddev_suspend() is redundant and
> potentially harmful now. If timer is about to be woken up but gets
> deleted, 'in_sync' will remain 0 until the next write, causing array
> to stay in the 'active' state instead of transitioning to 'clean'.
>
> Commit 0d9f4f135eb6 ("MD: Add del_timer_sync to mddev_suspend (fix
> nasty panic))" introduced this deletion for dm, because if timer fired
> after dm is destroyed, the resource which the timer depends on might
> have been freed.
>
> However, commit 0dd84b319352 ("md: call __md_stop_writes in md_stop")
> added __md_stop_writes() to md_stop(), which is called before freeing
> resource. Timer is deleted in __md_stop_writes(), and the origin issue
> is resolved. Therefore, delete safemode_timer can be removed safely now.
>
> Signed-off-by: Li Nan <linan122@xxxxxxxxxx>

Applied to md-6.11. Thanks!

Song