1 files changed, 31 insertions, 28 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index ac734e5bbe48..e477af8596e2 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -550,9 +550,9 @@ static int __multipath_map(struct dm_target *ti, struct request *clone,
 		pgpath = choose_pgpath(m, nr_bytes);
 
 	if (!pgpath) {
-		if (!must_push_back_rq(m))
-			r = -EIO;	/* Failed */
-		return r;
+		if (must_push_back_rq(m))
+			return DM_MAPIO_DELAY_REQUEUE;
+		return -EIO;	/* Failed */
 	} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
 		   test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
 		pg_init_all_paths(m);
@@ -680,9 +680,11 @@ static int multipath_map_bio(struct dm_target *ti, struct bio *bio)
 	return __multipath_map_bio(m, bio, mpio);
 }
 
-static void process_queued_bios_list(struct multipath *m)
+static void process_queued_io_list(struct multipath *m)
 {
-	if (m->queue_mode == DM_TYPE_BIO_BASED)
+	if (m->queue_mode == DM_TYPE_MQ_REQUEST_BASED)
+		dm_mq_kick_requeue_list(dm_table_get_md(m->ti->table));
+	else if (m->queue_mode == DM_TYPE_BIO_BASED)
 		queue_work(kmultipathd, &m->process_queued_bios);
 }
 
@@ -752,7 +754,7 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
 
 	if (!queue_if_no_path) {
 		dm_table_run_md_queue_async(m->ti->table);
-		process_queued_bios_list(m);
+		process_queued_io_list(m);
 	}
 
 	return 0;
@@ -1193,21 +1195,17 @@ static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv)
 
 static void multipath_wait_for_pg_init_completion(struct multipath *m)
 {
-	DECLARE_WAITQUEUE(wait, current);
-
-	add_wait_queue(&m->pg_init_wait, &wait);
+	DEFINE_WAIT(wait);
 
 	while (1) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
+		prepare_to_wait(&m->pg_init_wait, &wait, TASK_UNINTERRUPTIBLE);
 
 		if (!atomic_read(&m->pg_init_in_progress))
 			break;
 
 		io_schedule();
 	}
-	set_current_state(TASK_RUNNING);
-
-	remove_wait_queue(&m->pg_init_wait, &wait);
+	finish_wait(&m->pg_init_wait, &wait);
 }
 
 static void flush_multipath_work(struct multipath *m)
@@ -1308,7 +1306,7 @@ out:
 	spin_unlock_irqrestore(&m->lock, flags);
 	if (run_queue) {
 		dm_table_run_md_queue_async(m->ti->table);
-		process_queued_bios_list(m);
+		process_queued_io_list(m);
 	}
 
 	return r;
@@ -1506,7 +1504,7 @@ static void pg_init_done(void *data, int errors)
 	}
 	clear_bit(MPATHF_QUEUE_IO, &m->flags);
 
-	process_queued_bios_list(m);
+	process_queued_io_list(m);
 
 	/*
 	 * Wake up any thread waiting to suspend.
@@ -1521,10 +1519,10 @@ static void activate_path(struct work_struct *work)
 {
 	struct pgpath *pgpath =
 		container_of(work, struct pgpath, activate_path.work);
+	struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
 
-	if (pgpath->is_active)
-		scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
-				 pg_init_done, pgpath);
+	if (pgpath->is_active && !blk_queue_dying(q))
+		scsi_dh_activate(q, pg_init_done, pgpath);
 	else
 		pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
 }
@@ -1532,6 +1530,14 @@ static void activate_path(struct work_struct *work)
 static int noretry_error(int error)
 {
 	switch (error) {
+	case -EBADE:
+		/*
+		 * EBADE signals an reservation conflict.
+		 * We shouldn't fail the path here as we can communicate with
+		 * the target.  We should failover to the next path, but in
+		 * doing so we might be causing a ping-pong between paths.
+		 * So just return the reservation conflict error.
+		 */
 	case -EOPNOTSUPP:
 	case -EREMOTEIO:
 	case -EILSEQ:
@@ -1576,9 +1582,6 @@ static int do_end_io(struct multipath *m, struct request *clone,
 		if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
 			if (!must_push_back_rq(m))
 				r = -EIO;
-		} else {
-			if (error == -EBADE)
-				r = error;
 		}
 	}
 
@@ -1627,9 +1630,6 @@ static int do_end_io_bio(struct multipath *m, struct bio *clone,
 			if (!must_push_back_bio(m))
 				return -EIO;
 			return DM_ENDIO_REQUEUE;
-		} else {
-			if (error == -EBADE)
-				return error;
 		}
 	}
 
@@ -1941,7 +1941,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
 		if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
 			pg_init_all_paths(m);
 		dm_table_run_md_queue_async(m->ti->table);
-		process_queued_bios_list(m);
+		process_queued_io_list(m);
 	}
 
 	/*
@@ -1994,11 +1994,14 @@ static int multipath_busy(struct dm_target *ti)
 	struct priority_group *pg, *next_pg;
 	struct pgpath *pgpath;
 
-	/* pg_init in progress or no paths available */
-	if (atomic_read(&m->pg_init_in_progress) ||
-	    (!atomic_read(&m->nr_valid_paths) && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)))
+	/* pg_init in progress */
+	if (atomic_read(&m->pg_init_in_progress))
 		return true;
 
+	/* no paths available, for blk-mq: rely on IO mapping to delay requeue */
+	if (!atomic_read(&m->nr_valid_paths) && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
+		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);