4.19-stable review patch. If anyone has any objections, please let me know.
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From: Junxiao Bi junxiao.bi@oracle.com
[ Upstream commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d ]
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") Cc: stable@vger.kernel.org # v5.19+ Signed-off-by: Junxiao Bi junxiao.bi@oracle.com Reviewed-by: Yu Kuai yukuai3@huawei.com Signed-off-by: Song Liu song@kernel.org Link: https://lore.kernel.org/r/20231108182216.73611-2-junxiao.bi@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/raid5.c | 12 ------------ 1 file changed, 12 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index b98abe927d06..e2fcc09a18cd 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -44,7 +44,6 @@ */
#include <linux/blkdev.h> -#include <linux/delay.h> #include <linux/kthread.h> #include <linux/raid/pq.h> #include <linux/async_tx.h> @@ -6330,18 +6329,7 @@ static void raid5d(struct md_thread *thread) spin_unlock_irq(&conf->device_lock); md_check_recovery(mddev); spin_lock_irq(&conf->device_lock); - - /* - * Waiting on MD_SB_CHANGE_PENDING below may deadlock - * seeing md_check_recovery() is needed to clear - * the flag when using mdmon. - */ - continue; } - - wait_event_lock_irq(mddev->sb_wait, - !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags), - conf->device_lock); } pr_debug("%d stripes handled\n", handled);