md-cluster: re-add capabilities
When "re-add" is writted to /sys/block/mdXX/md/dev-YYY/state,
the clustered md:
1. Sends RE_ADD message with the desc_nr. Nodes receiving the message
clear the Faulty bit in their respective rdev->flags.
2. The node initiating re-add, gathers the bitmaps of all nodes
and copies them into the local bitmap. It does not clear the bitmap
from which it is copying.
3. Initiating node schedules a md recovery to sync the devices.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 429e95e..d9cac48 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2596,8 +2596,17 @@
}
} else if (cmd_match(buf, "re-add")) {
if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1)) {
- clear_bit(Faulty, &rdev->flags);
- err = add_bound_rdev(rdev);
+ /* clear_bit is performed _after_ all the devices
+ * have their local Faulty bit cleared. If any writes
+ * happen in the meantime in the local node, they
+ * will land in the local bitmap, which will be synced
+ * by this node eventually
+ */
+ if (!mddev_is_clustered(rdev->mddev) ||
+ (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
+ clear_bit(Faulty, &rdev->flags);
+ err = add_bound_rdev(rdev);
+ }
} else
err = -EBUSY;
}