block: fix missing nr_hw_queues update in blk_mq_realloc_tag_set_tags

The commit ee9d55210c2f ("blk-mq: simplify blk_mq_realloc_tag_set_tags")
cleaned up the function blk_mq_realloc_tag_set_tags. After this change,
the function does not update nr_hw_queues of struct blk_mq_tag_set when
new nr_hw_queues value is smaller than original. This results in failure
of queue number change of block devices. To avoid the failure, add the
missing nr_hw_queues update.

Fixes: ee9d55210c2f ("blk-mq: simplify blk_mq_realloc_tag_set_tags")
Reported-by: Chaitanya Kulkarni <chaitanyak@nvidia.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/linux-block/20221118140640.featvt3fxktfquwh@shindev/
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221122084917.2034220-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index ee16b4c..cdd8efc 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4381,7 +4381,7 @@ static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set,
        struct blk_mq_tags **new_tags;
 
        if (set->nr_hw_queues >= new_nr_hw_queues)
-               return 0;
+               goto done;
 
        new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *),
                                GFP_KERNEL, set->numa_node);
@@ -4393,8 +4393,8 @@ static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set,
                       sizeof(*set->tags));
        kfree(set->tags);
        set->tags = new_tags;
+done:
        set->nr_hw_queues = new_nr_hw_queues;
-
        return 0;
 }