btrfs: raid56: reduce indentation in lock_stripe_add

In lock_stripe_add() we're traversing the stripe hash list and check if
the current list element's raid_map equals is equal to the raid bio's
raid_map. If both are equal we continue processing.

If we'd check for inequality instead of equality we can reduce one level
of indentation.
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/raid56.c

@@ -682,10 +682,12 @@ static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
 
 	spin_lock_irqsave(&h->lock, flags);
 	list_for_each_entry(cur, &h->hash_list, hash_list) {
-		if (cur->bbio->raid_map[0] == rbio->bbio->raid_map[0]) {
+		if (cur->bbio->raid_map[0] != rbio->bbio->raid_map[0])
+			continue;
+
 		spin_lock(&cur->bio_list_lock);
 
-			/* can we steal this cached rbio's pages? */
+		/* Can we steal this cached rbio's pages? */
 		if (bio_list_empty(&cur->bio_list) &&
 		    list_empty(&cur->plug_list) &&
 		    test_bit(RBIO_CACHE_BIT, &cur->flags) &&
@@ -700,7 +702,7 @@ static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
 			goto lockit;
 		}
 
-			/* can we merge into the lock owner? */
+		/* Can we merge into the lock owner? */
 		if (rbio_can_merge(cur, rbio)) {
 			merge_rbio(cur, rbio);
 			spin_unlock(&cur->bio_list_lock);
@@ -711,15 +713,11 @@ static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
 
 
 		/*
-			 * we couldn't merge with the running
-			 * rbio, see if we can merge with the
-			 * pending ones.  We don't have to
-			 * check for rmw_locked because there
-			 * is no way they are inside finish_rmw
-			 * right now
+		 * We couldn't merge with the running rbio, see if we can merge
+		 * with the pending ones.  We don't have to check for rmw_locked
+		 * because there is no way they are inside finish_rmw right now
 		 */
-			list_for_each_entry(pending, &cur->plug_list,
-					    plug_list) {
+		list_for_each_entry(pending, &cur->plug_list, plug_list) {
 			if (rbio_can_merge(pending, rbio)) {
 				merge_rbio(pending, rbio);
 				spin_unlock(&cur->bio_list_lock);
@@ -729,16 +727,15 @@ static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
 			}
 		}
 
-			/* no merging, put us on the tail of the plug list,
-			 * our rbio will be started with the currently
-			 * running rbio unlocks
+		/*
+		 * No merging, put us on the tail of the plug list, our rbio
+		 * will be started with the currently running rbio unlocks
 		 */
 		list_add_tail(&rbio->plug_list, &cur->plug_list);
 		spin_unlock(&cur->bio_list_lock);
 		ret = 1;
 		goto out;
 	}
-	}
 lockit:
 	refcount_inc(&rbio->refs);
 	list_add(&rbio->hash_list, &h->hash_list);