Patch "ext4: fix quota inconsistency during orphan cleanup for read-only mounts" has been added to the 4.9-stable tree

@@ -2334,6 +2334,7 @@ static void ext4_orphan_cleanup(struct s
 	unsigned int s_flags = sb->s_flags;
 	int nr_orphans = 0, nr_truncates = 0;
 #ifdef CONFIG_QUOTA
+	int quota_update = 0;
 	int i;
 #endif
 	if (!es->s_last_orphan) {

@@ -2372,14 +2373,32 @@ static void ext4_orphan_cleanup(struct s
 #ifdef CONFIG_QUOTA
 	/* Needed for iput() to work correctly and not trash data */
 	sb->s_flags |= MS_ACTIVE;
-	/* Turn on journaled quotas so that they are updated correctly */
+
+	/*
+	 * Turn on quotas which were not enabled for read-only mounts if
+	 * filesystem has quota feature, so that they are updated correctly.
+	 */
+	if (ext4_has_feature_quota(sb) && (s_flags & MS_RDONLY)) {
+		int ret = ext4_enable_quotas(sb);
+
+		if (!ret)
+			quota_update = 1;
+		else
+			ext4_msg(sb, KERN_ERR,
+				"Cannot turn on quotas: error %d", ret);
+	}
+
+	/* Turn on journaled quotas used for old sytle */
 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
 		if (EXT4_SB(sb)->s_qf_names[i]) {
 			int ret = ext4_quota_on_mount(sb, i);
-			if (ret < 0)
+
+			if (!ret)
+				quota_update = 1;
+			else
 				ext4_msg(sb, KERN_ERR,
 					"Cannot turn on journaled "
-					"quota: error %d", ret);
+					"quota: type %d: error %d", i, ret);
 		}
 	}
 #endif

@@ -2438,10 +2457,12 @@ static void ext4_orphan_cleanup(struct s
 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
 		       PLURAL(nr_truncates));
 #ifdef CONFIG_QUOTA
-	/* Turn off journaled quotas if they were enabled for orphan cleanup */
-	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
-		if (EXT4_SB(sb)->s_qf_names[i] && sb_dqopt(sb)->files[i])
-			dquot_quota_off(sb, i);
+	/* Turn off quotas if they were enabled for orphan cleanup */
+	if (quota_update) {
+		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
+			if (sb_dqopt(sb)->files[i])
+				dquot_quota_off(sb, i);
+		}
 	}
 #endif
 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */

@@ -5365,6 +5386,9 @@ static int ext4_enable_quotas(struct sup
 				DQUOT_USAGE_ENABLED |
 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
 			if (err) {
+				for (type--; type >= 0; type--)
+					dquot_quota_off(sb, type);
+
 				ext4_warning(sb,
 					"Failed to enable quota tracking "
 					"(type=%d, err=%d). Please run "