1 files changed, 28 insertions, 35 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0e8ab5bb3575..c8faa2b85842 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -366,7 +366,7 @@ static struct pgpath *choose_path_in_pg(struct multipath *m,
 
 	pgpath = path_to_pgpath(path);
 
-	if (unlikely(lockless_dereference(m->current_pg) != pg)) {
+	if (unlikely(READ_ONCE(m->current_pg) != pg)) {
 		/* Only update current_pgpath if pg changed */
 		spin_lock_irqsave(&m->lock, flags);
 		m->current_pgpath = pgpath;
@@ -390,7 +390,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
 	}
 
 	/* Were we instructed to switch PG? */
-	if (lockless_dereference(m->next_pg)) {
+	if (READ_ONCE(m->next_pg)) {
 		spin_lock_irqsave(&m->lock, flags);
 		pg = m->next_pg;
 		if (!pg) {
@@ -406,7 +406,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
 
 	/* Don't change PG until it has no remaining paths */
 check_current_pg:
-	pg = lockless_dereference(m->current_pg);
+	pg = READ_ONCE(m->current_pg);
 	if (pg) {
 		pgpath = choose_path_in_pg(m, pg, nr_bytes);
 		if (!IS_ERR_OR_NULL(pgpath))
@@ -473,7 +473,7 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 	struct request *clone;
 
 	/* Do we need to select a new pgpath? */
-	pgpath = lockless_dereference(m->current_pgpath);
+	pgpath = READ_ONCE(m->current_pgpath);
 	if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags))
 		pgpath = choose_pgpath(m, nr_bytes);
 
@@ -499,12 +499,9 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 	if (IS_ERR(clone)) {
 		/* EBUSY, ENODEV or EWOULDBLOCK: requeue */
 		bool queue_dying = blk_queue_dying(q);
-		DMERR_LIMIT("blk_get_request() returned %ld%s - requeuing",
-			    PTR_ERR(clone), queue_dying ? " (path offline)" : "");
 		if (queue_dying) {
 			atomic_inc(&m->pg_init_in_progress);
 			activate_or_offline_path(pgpath);
-			return DM_MAPIO_REQUEUE;
 		}
 		return DM_MAPIO_DELAY_REQUEUE;
 	}
@@ -536,7 +533,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
 	bool queue_io;
 
 	/* Do we need to select a new pgpath? */
-	pgpath = lockless_dereference(m->current_pgpath);
+	pgpath = READ_ONCE(m->current_pgpath);
 	queue_io = test_bit(MPATHF_QUEUE_IO, &m->flags);
 	if (!pgpath || !queue_io)
 		pgpath = choose_pgpath(m, nr_bytes);
@@ -566,7 +563,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
 	mpio->nr_bytes = nr_bytes;
 
 	bio->bi_status = 0;
-	bio->bi_bdev = pgpath->path.dev->bdev;
+	bio_set_dev(bio, pgpath->path.dev->bdev);
 	bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
 
 	if (pgpath->pg->ps.type->start_io)
@@ -633,19 +630,15 @@ static void process_queued_bios(struct work_struct *work)
 		case DM_MAPIO_REMAPPED:
 			generic_make_request(bio);
 			break;
+		case 0:
+			break;
+		default:
+			WARN_ONCE(true, "__multipath_map_bio() returned %d\n", r);
 		}
 	}
 	blk_finish_plug(&plug);
 }
 
-static void assign_bit(bool value, long nr, unsigned long *addr)
-{
-	if (value)
-		set_bit(nr, addr);
-	else
-		clear_bit(nr, addr);
-}
-
 /*
  * If we run out of usable paths, should we queue I/O or error it?
  */
@@ -655,11 +648,11 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-	assign_bit((save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) ||
-		   (!save_old_value && queue_if_no_path),
-		   MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-	assign_bit(queue_if_no_path || dm_noflush_suspending(m->ti),
-		   MPATHF_QUEUE_IF_NO_PATH, &m->flags);
+	assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags,
+		   (save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) ||
+		   (!save_old_value && queue_if_no_path));
+	assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags,
+		   queue_if_no_path || dm_noflush_suspending(m->ti));
 	spin_unlock_irqrestore(&m->lock, flags);
 
 	if (!queue_if_no_path) {
@@ -699,7 +692,7 @@ static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg,
 	struct path_selector_type *pst;
 	unsigned ps_argc;
 
-	static struct dm_arg _args[] = {
+	static const struct dm_arg _args[] = {
 		{0, 1024, "invalid number of path selector args"},
 	};
 
@@ -823,7 +816,7 @@ retain:
 static struct priority_group *parse_priority_group(struct dm_arg_set *as,
 						   struct multipath *m)
 {
-	static struct dm_arg _args[] = {
+	static const struct dm_arg _args[] = {
 		{1, 1024, "invalid number of paths"},
 		{0, 1024, "invalid number of selector args"}
 	};
@@ -899,7 +892,7 @@ static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
 	int ret;
 	struct dm_target *ti = m->ti;
 
-	static struct dm_arg _args[] = {
+	static const struct dm_arg _args[] = {
 		{0, 1024, "invalid number of hardware handler args"},
 	};
 
@@ -951,7 +944,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
 	struct dm_target *ti = m->ti;
 	const char *arg_name;
 
-	static struct dm_arg _args[] = {
+	static const struct dm_arg _args[] = {
 		{0, 8, "invalid number of feature args"},
 		{1, 50, "pg_init_retries must be between 1 and 50"},
 		{0, 60000, "pg_init_delay_msecs must be between 0 and 60000"},
@@ -1020,7 +1013,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
 static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv)
 {
 	/* target arguments */
-	static struct dm_arg _args[] = {
+	static const struct dm_arg _args[] = {
 		{0, 1024, "invalid number of priority groups"},
 		{0, 1024, "invalid initial priority group number"},
 	};
@@ -1380,6 +1373,7 @@ static void pg_init_done(void *data, int errors)
 	case SCSI_DH_RETRY:
 		/* Wait before retrying. */
 		delay_retry = 1;
+		/* fall through */
 	case SCSI_DH_IMM_RETRY:
 	case SCSI_DH_RES_TEMP_UNAVAIL:
 		if (pg_init_limit_reached(m, pgpath))
@@ -1458,7 +1452,6 @@ static int noretry_error(blk_status_t error)
 	case BLK_STS_TARGET:
 	case BLK_STS_NEXUS:
 	case BLK_STS_MEDIUM:
-	case BLK_STS_RESOURCE:
 		return 1;
 	}
 
@@ -1585,8 +1578,8 @@ static void multipath_resume(struct dm_target *ti)
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-	assign_bit(test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags),
-		   MPATHF_QUEUE_IF_NO_PATH, &m->flags);
+	assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags,
+		   test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags));
 	spin_unlock_irqrestore(&m->lock, flags);
 }
 
@@ -1801,7 +1794,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
 	struct pgpath *current_pgpath;
 	int r;
 
-	current_pgpath = lockless_dereference(m->current_pgpath);
+	current_pgpath = READ_ONCE(m->current_pgpath);
 	if (!current_pgpath)
 		current_pgpath = choose_pgpath(m, 0);
 
@@ -1823,7 +1816,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
 	}
 
 	if (r == -ENOTCONN) {
-		if (!lockless_dereference(m->current_pg)) {
+		if (!READ_ONCE(m->current_pg)) {
 			/* Path status changed, redo selection */
 			(void) choose_pgpath(m, 0);
 		}
@@ -1892,9 +1885,9 @@ static int multipath_busy(struct dm_target *ti)
 		return (m->queue_mode != DM_TYPE_MQ_REQUEST_BASED);
 
 	/* Guess which priority_group will be used at next mapping time */
-	pg = lockless_dereference(m->current_pg);
-	next_pg = lockless_dereference(m->next_pg);
-	if (unlikely(!lockless_dereference(m->current_pgpath) && next_pg))
+	pg = READ_ONCE(m->current_pg);
+	next_pg = READ_ONCE(m->next_pg);
+	if (unlikely(!READ_ONCE(m->current_pgpath) && next_pg))
 		pg = next_pg;
 
 	if (!pg) {