md-cluster: wakeup thread if activated a spare disk

When a device is re-added, it will ultimately need
to be activated and that happens in md_check_recovery,
so we need to set MD_RECOVERY_NEEDED right after
remove_and_add_spares.

A specifical issue without the change is that when
one node perform fail/remove/readd on a disk, but
slave nodes could not add the disk back to array as
expected (added as missed instead of in sync). So
give slave nodes a chance to do resync.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8cc4bbc..06f6e81 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8694,6 +8694,11 @@ static void check_sb_changes(struct mddev *mddev, struct md_rdev *rdev)
                                ret = remove_and_add_spares(mddev, rdev2);
                                pr_info("Activated spare: %s\n",
                                                bdevname(rdev2->bdev,b));
+                               /* wakeup mddev->thread here, so array could
+                                * perform resync with the new activated disk */
+                               set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+                               md_wakeup_thread(mddev->thread);
+
                        }
                        /* device faulty
                         * We just want to do the minimum to mark the disk