dm mpath: don't return -EIO from dm_report_EIO

Instead just turn the macro into a helper for the warning message.
This removes an unnecessary assignment and will allow the next commit to
fix a place where -EIO is the wrong return value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-mpath.c

@@ -447,7 +447,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
  * it has been invoked.
  */
 #define dm_report_EIO(m)						\
-({									\
+do {									\
 	struct mapped_device *md = dm_table_get_md((m)->ti->table);	\
 									\
 	pr_debug("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d\n", \
@@ -455,8 +455,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
 		 test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags),	\
 		 test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags),	\
 		 dm_noflush_suspending((m)->ti));			\
-	-EIO;								\
-})
+} while (0)
 
 /*
  * Map cloned requests (request-based multipath)
@@ -481,7 +480,8 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 	if (!pgpath) {
 		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
 			return DM_MAPIO_DELAY_REQUEUE;
-		return dm_report_EIO(m);	/* Failed */
+		dm_report_EIO(m);	/* Failed */
+		return -EIO;
 	} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
 		   test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
 		if (pg_init_all_paths(m))
@@ -558,7 +558,8 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
 	if (!pgpath) {
 		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
 			return DM_MAPIO_REQUEUE;
-		return dm_report_EIO(m);
+		dm_report_EIO(m);
+		return -EIO;
 	}
 
 	mpio->pgpath = pgpath;
@@ -1493,7 +1494,7 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
 		if (atomic_read(&m->nr_valid_paths) == 0 &&
 		    !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
 			if (error == -EIO)
-				error = dm_report_EIO(m);
+				dm_report_EIO(m);
 			/* complete with the original error */
 			r = DM_ENDIO_DONE;
 		}
@@ -1524,8 +1525,10 @@ static int do_end_io_bio(struct multipath *m, struct bio *clone,
 		fail_path(mpio->pgpath);
 
 	if (atomic_read(&m->nr_valid_paths) == 0 &&
-	    !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
-		return dm_report_EIO(m);
+	    !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
+		dm_report_EIO(m);
+		return -EIO;
+	}
 
 	/* Queue for the daemon to resubmit */
 	dm_bio_restore(get_bio_details_from_bio(clone), clone);