blk-mq: fix and simplify tag iteration for the timeout handler

Don't do a kmalloc from timer to handle timeouts, chances are we could be
under heavy load or similar and thus just miss out on the timeouts.
Fortunately it is very easy to just iterate over all in use tags, and doing
this properly actually cleans up the blk_mq_busy_iter API as well, and
prepares us for the next patch by passing a reserved argument to the
iterator.

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

1 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index cb217c16990d..0eb0f642be4b 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -86,6 +86,9 @@ typedef int (init_request_fn)(void *, struct request *, unsigned int,
 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
                 unsigned int);
 
+typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
+                bool);
+
 struct blk_mq_ops {
         /*
          * Queue request
@@ -174,7 +177,8 @@ void blk_mq_stop_hw_queues(struct request_queue *q);
 void blk_mq_start_hw_queues(struct request_queue *q);
 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
-void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
+void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
+                void *priv);
 
 /*
  * Driver command data is immediately after the request. So subtract request