block: add a poll_fn callback to struct request_queue
That we we can also poll non blk-mq queues. Mostly needed for
the NVMe multipath code, but could also be useful elsewhere.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e4d2490..95ea588 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -37,6 +37,7 @@
#include "blk-wbt.h"
#include "blk-mq-sched.h"
+static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie);
static void blk_mq_poll_stats_start(struct request_queue *q);
static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
@@ -2499,6 +2500,8 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
spin_lock_init(&q->requeue_lock);
blk_queue_make_request(q, blk_mq_make_request);
+ if (q->mq_ops->poll)
+ q->poll_fn = blk_mq_poll;
/*
* Do this after blk_queue_make_request() overrides it...
@@ -2961,20 +2964,14 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
return false;
}
-bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
+static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
{
struct blk_mq_hw_ctx *hctx;
- struct blk_plug *plug;
struct request *rq;
- if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) ||
- !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
+ if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
return false;
- plug = current->plug;
- if (plug)
- blk_flush_plug_list(plug, false);
-
hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
if (!blk_qc_t_is_internal(cookie))
rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
@@ -2992,7 +2989,6 @@ bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
return __blk_mq_poll(hctx, rq);
}
-EXPORT_SYMBOL_GPL(blk_mq_poll);
static int __init blk_mq_init(void)
{
