dm: factor out dm_io_complete

Optimizes dm_io_dec_pending() slightly by avoiding local variables.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm.c

@@ -841,28 +841,14 @@ static int __noflush_suspending(struct mapped_device *md)
 	return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
 }
 
-/*
- * Decrements the number of outstanding ios that a bio has been
- * cloned into, completing the original io if necc.
- */
-void dm_io_dec_pending(struct dm_io *io, blk_status_t error)
+static void dm_io_complete(struct dm_io *io)
 {
-	unsigned long flags;
 	blk_status_t io_error;
-	struct bio *bio;
 	struct mapped_device *md = io->md;
+	struct bio *bio = io->orig_bio;
 
-	/* Push-back supersedes any I/O errors */
-	if (unlikely(error)) {
-		spin_lock_irqsave(&io->endio_lock, flags);
-		if (!(io->status == BLK_STS_DM_REQUEUE && __noflush_suspending(md)))
-			io->status = error;
-		spin_unlock_irqrestore(&io->endio_lock, flags);
-	}
-
-	if (atomic_dec_and_test(&io->io_count)) {
-		bio = io->orig_bio;
 	if (io->status == BLK_STS_DM_REQUEUE) {
+		unsigned long flags;
 		/*
 		 * Target requested pushing back the I/O.
 		 */
@@ -923,7 +909,26 @@ void dm_io_dec_pending(struct dm_io *io, blk_status_t error)
 			bio->bi_status = io_error;
 		bio_endio(bio);
 	}
+}
+
+/*
+ * Decrements the number of outstanding ios that a bio has been
+ * cloned into, completing the original io if necc.
+ */
+void dm_io_dec_pending(struct dm_io *io, blk_status_t error)
+{
+	/* Push-back supersedes any I/O errors */
+	if (unlikely(error)) {
+		unsigned long flags;
+		spin_lock_irqsave(&io->endio_lock, flags);
+		if (!(io->status == BLK_STS_DM_REQUEUE &&
+		      __noflush_suspending(io->md)))
+			io->status = error;
+		spin_unlock_irqrestore(&io->endio_lock, flags);
 	}
+
+	if (atomic_dec_and_test(&io->io_count))
+		dm_io_complete(io);
 }
 
 void disable_discard(struct mapped_device *md)
@@ -1562,7 +1567,7 @@ static void dm_split_and_process_bio(struct mapped_device *md,
 
 	if (bio->bi_opf & REQ_PREFLUSH) {
 		error = __send_empty_flush(&ci);
-		/* dm_io_dec_pending submits any data associated with flush */
+		/* dm_io_complete submits any data associated with flush */
 		goto out;
 	}
 
@@ -1575,7 +1580,7 @@ static void dm_split_and_process_bio(struct mapped_device *md,
 	 * Remainder must be passed to submit_bio_noacct() so it gets handled
 	 * *after* bios already submitted have been completely processed.
 	 * We take a clone of the original to store in ci.io->orig_bio to be
-	 * used by dm_end_io_acct() and for dm_io_dec_pending() to use for
+	 * used by dm_end_io_acct() and for dm_io_complete() to use for
 	 * completion handling.
 	 */
 	orig_bio = bio_split(bio, bio_sectors(bio) - ci.sector_count,