dm mpath: rework __map_bio()

so that it follows same pattern as request-based
multipath_clone_and_map()

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 4b48183..ab6ccd6 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -574,15 +574,20 @@ static void multipath_release_clone(struct request *clone,
  * Map cloned bios (bio-based multipath)
  */
 
-static void multipath_queue_bio(struct multipath *m, struct bio *bio)
+static void __multipath_queue_bio(struct multipath *m, struct bio *bio)
 {
-       unsigned long flags;
-
        /* Queue for the daemon to resubmit */
-       spin_lock_irqsave(&m->lock, flags);
        bio_list_add(&m->queued_bios, bio);
        if (!test_bit(MPATHF_QUEUE_IO, &m->flags))
                queue_work(kmultipathd, &m->process_queued_bios);
+}
+
+static void multipath_queue_bio(struct multipath *m, struct bio *bio)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&m->lock, flags);
+       __multipath_queue_bio(m, bio);
        spin_unlock_irqrestore(&m->lock, flags);
 }
 
@@ -590,24 +595,24 @@ static struct pgpath *__map_bio(struct multipath *m, struct bio *bio)
 {
        struct pgpath *pgpath;
        unsigned long flags;
-       bool queue_io;
 
        /* Do we need to select a new pgpath? */
        pgpath = READ_ONCE(m->current_pgpath);
        if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags))
                pgpath = choose_pgpath(m, bio->bi_iter.bi_size);
 
-       /* MPATHF_QUEUE_IO might have been cleared by choose_pgpath. */
-       queue_io = test_bit(MPATHF_QUEUE_IO, &m->flags);
+       if (!pgpath) {
+               spin_lock_irqsave(&m->lock, flags);
+               if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
+                       __multipath_queue_bio(m, bio);
+                       pgpath = ERR_PTR(-EAGAIN);
+               }
+               spin_unlock_irqrestore(&m->lock, flags);
 
-       if ((pgpath && queue_io) ||
-           (!pgpath && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))) {
+       } else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
+                  test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
                multipath_queue_bio(m, bio);
-
-               /* PG_INIT_REQUIRED cannot be set without QUEUE_IO */
-               if (queue_io || test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
-                       pg_init_all_paths(m);
-
+               pg_init_all_paths(m);
                return ERR_PTR(-EAGAIN);
        }