commit 579f921700e43eb7c27c24250869576b19da4f93
author Christoph Hellwig <hch@infradead.org> Sun Oct 06 10:09:56 2013 -0700
committer Jens Axboe <axboe@kernel.dk> Tue Oct 15 09:14:45 2013 -0600
tree 5306951dd56a6dd4d145974e9198050d73a9437f
parent 64093174ba03b0e11df01cb401264983cc71f761

blk-mq: fix blk_mq_start_stopped_hw_queues from irq context

The only caller of blk_mq_start_stopped_hw_queues is in irq context,
leading to lockdep splat when it actually gets called.  Fix this by
deferring the hw queue run to workqueue context.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2b85029..923e9e1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -686,7 +686,8 @@
 		if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
 			continue;
 
-		blk_mq_start_hw_queue(hctx);
+		clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
+		blk_mq_run_hw_queue(hctx, true);
 	}
 }
 EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);