On Wed, Nov 8, 2023 at 10:22 AM Junxiao Bi <junxiao.bi@xxxxxxxxxx> wrote:
>
> This reverts commit 5e2cf333b7bd5d3e62595a44d598a254c697cd74.
>
> That commit introduced the following race and can cause system hung.
>
> md_write_start: raid5d:
> // mddev->in_sync == 1
> set "MD_SB_CHANGE_PENDING"
> // running before md_write_start wakeup it
> waiting "MD_SB_CHANGE_PENDING" cleared
> >>>>>>>>> hung
> wakeup mddev->thread
> ...
> waiting "MD_SB_CHANGE_PENDING" cleared
> >>>> hung, raid5d should clear this flag
> but get hung by same flag.
>
> The issue reverted commit fixing is fixed by last patch in a new way.
>
> Fixes: 5e2cf333b7bd ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d")
> Signed-off-by: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
The set looks good to me. Thanks!
Quick question: from the earlier thread, the issue was observed in
production. Have you reproduced the issue and thus verified the fix
works as expected?
Thanks,
Song
