[dm-devel] [PATCH 9/9] dm-mpath: Add nowait support

[Goldwyn Rodrigues]

From: Goldwyn Rodrigues <rgoldwyn at suse.com>

If there are no queues, bail if REQ_NOWAIT is set instead
of queueing up I/O.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn at suse.com>
---
 drivers/md/dm-mpath.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0e8ab5bb3575..c6572a9967dc 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -543,6 +543,11 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
 
 	if ((pgpath && queue_io) ||
 	    (!pgpath && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))) {
+		/* Bail if nowait is set */
+		if (bio->bi_opf & REQ_NOWAIT) {
+			bio_wouldblock_error(bio);
+			return DM_MAPIO_SUBMITTED;
+		}
 		/* Queue for the daemon to resubmit */
 		spin_lock_irqsave(&m->lock, flags);
 		bio_list_add(&m->queued_bios, bio);
-- 
2.12.3