dm raid: prohibit 'nosync' on new raid6 and reject resize during reshape

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-raid.c

@@ -2752,9 +2752,21 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
 	if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
 		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
 		rs_set_new(rs);
-	} else if (rs_is_reshaping(rs))
-		; /* skip rs setup */
-	else if (rs_takeover_requested(rs)) {
+		/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
+		if (rs_is_raid6(rs) &&
+		    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
+			ti->error = "'nosync' not allowed for new raid6 set";
+			return -EINVAL;
+		}
+		rs_setup_recovery(rs, 0);
+	} else if (rs_is_reshaping(rs)) {
+		/* Have to reject size change request during reshape */
+		if (calculated_dev_sectors != rs->dev[0].rdev.sectors) {
+			ti->error = "Can't resize a reshaping raid set";
+			return -EPERM;
+		}
+		/* skip setup rs */
+	} else if (rs_takeover_requested(rs)) {
 		if (rs_is_reshaping(rs)) {
 			ti->error = "Can't takeover a reshaping raid set";
 			return -EPERM;