[PATCH 4/5] blk-mq: Do not fail blk_mq_reg::queue_depth value of zero

[Alexander Gordeev]

Zero value of blk_mq_reg::queue_depth defaults to
BLK_MQ_MAX_DEPTH. Commit 1ffd49b ("blk-mq: Check queue
depth is valid") broke this default. This fix restores
the previous behaviour.

Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
---
 block/blk-mq.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index a8b4c79..6c2533a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1308,8 +1308,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
 
 	if (!reg->nr_hw_queues ||
 	    !reg->ops->queue_rq || !reg->ops->map_queue ||
-	    !reg->ops->alloc_hctx || !reg->ops->free_hctx ||
-	    (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN)))
+	    !reg->ops->alloc_hctx || !reg->ops->free_hctx)
 		return ERR_PTR(-EINVAL);
 
 	if (!reg->queue_depth)
@@ -1319,6 +1318,9 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
 		reg->queue_depth = BLK_MQ_MAX_DEPTH;
 	}
 
+	if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN))
+		return ERR_PTR(-EINVAL);
+
 	ctx = alloc_percpu(struct blk_mq_ctx);
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);
-- 
1.7.7.6

-- 
Regards,
Alexander Gordeev
agordeev@xxxxxxxxxx
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