Changes to improve zpool clear after mmp suspend

Signed-off-by: Don Brady <[email protected]>

module/zfs/spa.c

@@ -278,7 +278,7 @@ uint64_t	zfs_max_missing_tvds_cachefile = SPA_DVAS_PER_BP - 1;
 uint64_t	zfs_max_missing_tvds_scan = 0;
 
 /*
- * Debugging aid that pauses spa_sync() towards the end.
+ * Debugginr aid that pauses spa_sync() towards the end.
  */
 static const boolean_t	zfs_pause_spa_sync = B_FALSE;
 
@@ -3759,8 +3759,6 @@ spa_mmp_remote_host_activity(spa_t *spa)
 
 	nvlist_t *best_label;
 	uberblock_t best_ub;
-	uberblock_t *spa_ub = &spa->spa_uberblock;
-	uint16_t spa_mmp_seq = MMP_SEQ_VALID(spa_ub) ? MMP_SEQ(spa_ub) : 0;
 
 	/*
 	 * Locate the best uberblock on disk
@@ -3787,14 +3785,13 @@ spa_mmp_remote_host_activity(spa_t *spa)
 		return (B_TRUE);
 	}
 
-	/*
-	 * confirm that the best sequence is still from our host
-	 */
-	if (spa_mmp_seq != (MMP_SEQ_VALID(&best_ub) ? MMP_SEQ(&best_ub) : 0))
+	if (best_ub.ub_txg != spa->spa_uberblock.ub_txg ||
+	    best_ub.ub_timestamp != spa->spa_uberblock.ub_timestamp) {
 		return (B_TRUE);
+	}
 
 	/*
-	 * Finally perform an activity check looking for any remote writer
+	 * Perform an activity check looking for any remote writer
 	 */
 	return (spa_activity_check(spa, &spa->spa_uberblock, spa->spa_config,
 	    B_FALSE) != 0);

module/zfs/txg.c

@@ -550,6 +550,15 @@ txg_sync_thread(void *arg)
 			timer = (delta > timeout ? 0 : timeout - delta);
 		}
 
+		/*
+		 * When we're suspended, nothing should be changing and for
+		 * MMP we don't want to bump anything that would make it
+		 * harder to detect if another host is changing it when
+		 * resuming after a MMP suspend.
+		 */
+		if (spa_suspended(spa))
+			continue;
+
 		/*
 		 * Wait until the quiesce thread hands off a txg to us,
 		 * prompting it to do so if necessary.