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authorBart Van Assche <bvanassche@acm.org>2021-05-13 10:15:29 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-05-22 10:57:40 +0200
commit0b948f3c2149680b38757257d37406777338b0dc (patch)
tree9adc2c0ac0629d2837b730f264c5511e293d07c3 /block
parent5ab9857dde7c3ea3faef6b128d718cf8ba98721b (diff)
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blk-mq: Swap two calls in blk_mq_exit_queue()
[ Upstream commit 630ef623ed26c18a457cdc070cf24014e50129c2 ] If a tag set is shared across request queues (e.g. SCSI LUNs) then the block layer core keeps track of the number of active request queues in tags->active_queues. blk_mq_tag_busy() and blk_mq_tag_idle() update that atomic counter if the hctx flag BLK_MQ_F_TAG_QUEUE_SHARED is set. Make sure that blk_mq_exit_queue() calls blk_mq_tag_idle() before that flag is cleared by blk_mq_del_queue_tag_set(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Fixes: 0d2602ca30e4 ("blk-mq: improve support for shared tags maps") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20210513171529.7977-1-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index cf56bdad2e06..7b785855a6e4 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2489,10 +2489,12 @@ EXPORT_SYMBOL(blk_mq_init_allocated_queue);
void blk_mq_free_queue(struct request_queue *q)
{
- struct blk_mq_tag_set *set = q->tag_set;
+ struct blk_mq_tag_set *set = q->tag_set;
- blk_mq_del_queue_tag_set(q);
+ /* Checks hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED. */
blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
+ /* May clear BLK_MQ_F_TAG_QUEUE_SHARED in hctx->flags. */
+ blk_mq_del_queue_tag_set(q);
}
/* Basically redo blk_mq_init_queue with queue frozen */