Return early for case when no path exists, this eliminates the need for
extra nesting for the case when a path exists (the common case).
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm-mpath.c | 51 +++++++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 24 deletions(-)
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 971fbec..272e7d4 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -392,32 +392,35 @@ static int multipath_map(struct dm_target *ti, struct request *clone,
pgpath = m->current_pgpath;
- if (pgpath) {
- if (__pgpath_busy(pgpath))
- goto out_unlock;
+ if (!pgpath) {
+ if (!__must_push_back(m))
+ r = -EIO; /* Failed */
+ goto out_unlock;
+ }
+
+ if (__pgpath_busy(pgpath))
+ goto out_unlock;
- if (pg_ready(m)) {
- if (set_mapinfo(m, map_context) < 0)
- /* ENOMEM, requeue */
- goto out_unlock;
-
- bdev = pgpath->path.dev->bdev;
- clone->q = bdev_get_queue(bdev);
- clone->rq_disk = bdev->bd_disk;
- clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
- mpio = map_context->ptr;
- mpio->pgpath = pgpath;
- mpio->nr_bytes = nr_bytes;
- if (pgpath->pg->ps.type->start_io)
- pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
- &pgpath->path,
- nr_bytes);
- r = DM_MAPIO_REMAPPED;
+ if (pg_ready(m)) {
+ if (set_mapinfo(m, map_context) < 0)
+ /* ENOMEM, requeue */
goto out_unlock;
- }
- __pg_init_all_paths(m, 0);
- } else if (!__must_push_back(m))
- r = -EIO; /* Failed */
+
+ bdev = pgpath->path.dev->bdev;
+ clone->q = bdev_get_queue(bdev);
+ clone->rq_disk = bdev->bd_disk;
+ clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
+ mpio = map_context->ptr;
+ mpio->pgpath = pgpath;
+ mpio->nr_bytes = nr_bytes;
+ if (pgpath->pg->ps.type->start_io)
+ pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
+ &pgpath->path,
+ nr_bytes);
+ r = DM_MAPIO_REMAPPED;
+ goto out_unlock;
+ }
+ __pg_init_all_paths(m, 0);
out_unlock:
spin_unlock_irqrestore(&m->lock, flags);
--
1.8.1.4
--
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