On 11/24/23 9:29 AM, Song Liu wrote:
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!
Thanks for the review.
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?
I didn't try reproducing this since the system hung on the code where the bad commit added, after revert it, this issue will not reproduce any more.
Thanks, Junxiao.
Thanks, Song
