From: Bart Van Assche <bvanassche@acm.org>
Date: Mon, 15 Aug 2022 17:00:42 +0000 (-0700)
Subject: null_blk: Modify the behavior of null_map_queues()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=10b41ea15e81a5597bc5944a7900e9a790bd984a;p=linux.git

null_blk: Modify the behavior of null_map_queues()

Instead of returning -EINVAL if an internal inconsistency is detected,
fall back to a single submission queue. This patch prepares for changing
the return value of the .map_queues() callbacks into void.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220815170043.19489-2-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index c451c477978ff..535059209693b 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1555,7 +1555,9 @@ static int null_map_queues(struct blk_mq_tag_set *set)
 		} else {
 			pr_warn("tag set has unexpected nr_hw_queues: %d\n",
 				set->nr_hw_queues);
-			return -EINVAL;
+			WARN_ON_ONCE(true);
+			submit_queues = 1;
+			poll_queues = 0;
 		}
 	}