md-cluster: send BITMAP_NEEDS_SYNC message if reshaping is interrupted

We need to continue the reshaping if it was interrupted in
original node. So original node should call resync_bitmap
in case reshaping is aborted.

Then BITMAP_NEEDS_SYNC message is broadcasted to other nodes,
node which continues the reshaping should restart reshape from
mddev->reshape_position instead of from the first beginning.

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

2 files changed, 26 insertions, 5 deletions

diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 792e0218a42f..f1b870766deb 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -333,6 +333,12 @@ static void recover_bitmaps(struct md_thread *thread)
                         }
                 spin_unlock_irq(&cinfo->suspend_lock);
 
+                /* Kick off a reshape if needed */
+                if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
+                    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+                    mddev->reshape_position != MaxSector)
+                        md_wakeup_thread(mddev->sync_thread);
+
                 if (hi > 0) {
                         if (lo < mddev->recovery_cp)
                                 mddev->recovery_cp = lo;
@@ -1020,10 +1026,17 @@ static int leave(struct mddev *mddev)
         if (!cinfo)
                 return 0;
 
-        /* BITMAP_NEEDS_SYNC message should be sent when node
+        /*
+         * BITMAP_NEEDS_SYNC message should be sent when node
          * is leaving the cluster with dirty bitmap, also we
-         * can only deliver it when dlm connection is available */
-        if (cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector)
+         * can only deliver it when dlm connection is available.
+         *
+         * Also, we should send BITMAP_NEEDS_SYNC message in
+         * case reshaping is interrupted.
+         */
+        if ((cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector) ||
+            (mddev->reshape_position != MaxSector &&
+             test_bit(MD_CLOSING, &mddev->flags)))
                 resync_bitmap(mddev);
 
         set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index fa2bbdec9955..390f410e51dd 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8370,9 +8370,17 @@ void md_do_sync(struct md_thread *thread)
                 else if (!mddev->bitmap)
                         j = mddev->recovery_cp;
 
-        } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
+        } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
                 max_sectors = mddev->resync_max_sectors;
-        else {
+                /*
+                 * If the original node aborts reshaping then we continue the
+                 * reshaping, so set j again to avoid restart reshape from the
+                 * first beginning
+                 */
+                if (mddev_is_clustered(mddev) &&
+                    mddev->reshape_position != MaxSector)
+                        j = mddev->reshape_position;
+        } else {
                 /* recovery follows the physical size of devices */
                 max_sectors = mddev->dev_sectors;
                 j = MaxSector;