From 9bf59a611a5eb479f321fae34adc9f948de0a42f Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 28 Feb 2014 15:33:48 +0100 Subject: [PATCH] dm mpath: remove extra nesting in map function Return early for case when no path exists, and when the pathgroup isn't ready. This eliminates the need for extra nesting for the the common case. Signed-off-by: Mike Snitzer Signed-off-by: Hannes Reinecke --- drivers/md/dm-mpath.c | 46 ++++++++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 22 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 07ca77f..e7d80ba 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -398,29 +398,31 @@ static int multipath_map(struct dm_target *ti, struct request *clone, pgpath = m->current_pgpath; - if (pgpath) { - 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; - goto out_unlock; - } + if (!pgpath) { + if (!__must_push_back(m)) + r = -EIO; /* Failed */ + goto out_unlock; + } + if (!pg_ready(m)) { __pg_init_all_paths(m); - } else if (!__must_push_back(m)) - r = -EIO; /* Failed */ + goto out_unlock; + } + 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; out_unlock: spin_unlock_irqrestore(&m->lock, flags); -- 2.7.4