md-cluster: transfer the resync ownership to another node

When node A stops an array while the array is doing a resync, we need
to let another node B take over the resync task.

To achieve the goal, we need the A send an explicit BITMAP_NEEDS_SYNC
message to the cluster. And the node B which received that message will
invoke __recover_slot to do resync.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>

diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 24caabe..47199ad 100644 (file)
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -75,6 +75,7 @@ enum msg_type {
        NEWDISK,
        REMOVE,
        RE_ADD,
+       BITMAP_NEEDS_SYNC,
 };
 
 struct cluster_msg {
@@ -454,6 +455,11 @@ static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
                        __func__, __LINE__, msg->slot);
                process_readd_disk(mddev, msg);
                break;
+       case BITMAP_NEEDS_SYNC:
+               pr_info("%s: %d Received BITMAP_NEEDS_SYNC from %d\n",
+                       __func__, __LINE__, msg->slot);
+               __recover_slot(mddev, msg->slot);
+               break;
        default:
                pr_warn("%s:%d Received unknown message from %d\n",
                        __func__, __LINE__, msg->slot);
@@ -814,8 +820,17 @@ static int resync_start(struct mddev *mddev, sector_t lo, sector_t hi)
 
 static void resync_finish(struct mddev *mddev)
 {
+       struct md_cluster_info *cinfo = mddev->cluster_info;
+       struct cluster_msg cmsg;
+       int slot = cinfo->slot_number - 1;
+
        pr_info("%s:%d\n", __func__, __LINE__);
        resync_send(mddev, RESYNCING, 0, 0);
+       if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
+               cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
+               cmsg.slot = cpu_to_le32(slot);
+               sendmsg(cinfo, &cmsg);
+       }
 }
 
 static int area_resyncing(struct mddev *mddev, int direction,

diff --cc drivers/md/md.c
Simple merge