md/raid5: fix handling of bad blocks during recovery.

1/ We can only treat a known-bad-block like a read-error if we
   have the data that belongs in that block.  So fix that test.

2/ If we cannot recovery a stripe due to insufficient data,
   don't tell "md_done_sync" that the sync failed unless we really
   did fail something.  If we successfully record bad blocks,
   that is success.
Reported-by: "majianpeng" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/raid5.c

@@ -2471,18 +2471,19 @@ handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
 	int abort = 0;
 	int i;
 
-	md_done_sync(conf->mddev, STRIPE_SECTORS, 0);
 	clear_bit(STRIPE_SYNCING, &sh->state);
 	s->syncing = 0;
 	s->replacing = 0;
 	/* There is nothing more to do for sync/check/repair.
+	 * Don't even need to abort as that is handled elsewhere
+	 * if needed, and not always wanted e.g. if there is a known
+	 * bad block here.
 	 * For recover/replace we need to record a bad block on all
 	 * non-sync devices, or abort the recovery
 	 */
-	if (!test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery))
-		return;
-	/* During recovery devices cannot be removed, so locking and
-	 * refcounting of rdevs is not needed
+	if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
+		/* During recovery devices cannot be removed, so
+		 * locking and refcounting of rdevs is not needed
 		 */
 		for (i = 0; i < conf->raid_disks; i++) {
 			struct md_rdev *rdev = conf->disks[i].rdev;
@@ -2500,10 +2501,11 @@ handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
 						   STRIPE_SECTORS, 0))
 				abort = 1;
 		}
-	if (abort) {
-		conf->recovery_disabled = conf->mddev->recovery_disabled;
-		set_bit(MD_RECOVERY_INTR, &conf->mddev->recovery);
+		if (abort)
+			conf->recovery_disabled =
+				conf->mddev->recovery_disabled;
 	}
+	md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
 }
 
 static int want_replace(struct stripe_head *sh, int disk_idx)
@@ -3203,7 +3205,8 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
 			/* Not in-sync */;
 		else if (is_bad) {
 			/* also not in-sync */
-			if (!test_bit(WriteErrorSeen, &rdev->flags)) {
+			if (!test_bit(WriteErrorSeen, &rdev->flags) &&
+			    test_bit(R5_UPTODATE, &dev->flags)) {
 				/* treat as in-sync, but with a read error
 				 * which we can now try to correct
 				 */