From: Jens Axboe <ax...@kernel.dk>
Move the RCU vs SRCU logic into lock/unlock helpers, which makes
the actual functional bits within the locked region much easier
to read.
tj: Reordered in front of timeout revamp patches and added the missing
blk_mq_run_hw_queue() conversion.
Signed-off-by: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Tejun Heo <t...@kernel.org>
---
block/blk-mq.c | 66 ++++++++++++++++++++++++++++------------------------------
1 file changed, 32 insertions(+), 34 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 111e1aa..ddc9261 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -557,6 +557,22 @@ static void __blk_mq_complete_request(struct request *rq)
put_cpu();
}
+static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
+{
+ if (!(hctx->flags & BLK_MQ_F_BLOCKING))
+ rcu_read_unlock();
+ else
+ srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
+}
+
+static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx)
+{
+ if (!(hctx->flags & BLK_MQ_F_BLOCKING))
+ rcu_read_lock();
+ else
+ *srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
+}
+
/**
* blk_mq_complete_request - end I/O on a request
* @rq: the request being processed
@@ -1214,17 +1230,11 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx
*hctx)
*/
WARN_ON_ONCE(in_interrupt());
- if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
- rcu_read_lock();
- blk_mq_sched_dispatch_requests(hctx);
- rcu_read_unlock();
- } else {
- might_sleep();
+ might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
- srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
- blk_mq_sched_dispatch_requests(hctx);
- srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
- }
+ hctx_lock(hctx, &srcu_idx);
+ blk_mq_sched_dispatch_requests(hctx);
+ hctx_unlock(hctx, srcu_idx);
}
/*
@@ -1296,17 +1306,10 @@ bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx,
bool async)
* And queue will be rerun in blk_mq_unquiesce_queue() if it is
* quiesced.
*/
- if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
- rcu_read_lock();
- need_run = !blk_queue_quiesced(hctx->queue) &&
- blk_mq_hctx_has_pending(hctx);
- rcu_read_unlock();
- } else {
- srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
- need_run = !blk_queue_quiesced(hctx->queue) &&
- blk_mq_hctx_has_pending(hctx);
- srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
- }
+ hctx_lock(hctx, &srcu_idx);
+ need_run = !blk_queue_quiesced(hctx->queue) &&
+ blk_mq_hctx_has_pending(hctx);
+ hctx_unlock(hctx, srcu_idx);
if (need_run) {
__blk_mq_delay_run_hw_queue(hctx, async, 0);
@@ -1618,7 +1621,7 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx
*hctx, struct request *rq)
static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
struct request *rq,
- blk_qc_t *cookie, bool may_sleep)
+ blk_qc_t *cookie)
{
struct request_queue *q = rq->q;
struct blk_mq_queue_data bd = {
@@ -1668,25 +1671,20 @@ static void __blk_mq_try_issue_directly(struct
blk_mq_hw_ctx *hctx,
}
insert:
- blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep);
+ blk_mq_sched_insert_request(rq, false, run_queue, false,
+ hctx->flags & BLK_MQ_F_BLOCKING);
}
static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
struct request *rq, blk_qc_t *cookie)
{
- if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
- rcu_read_lock();
- __blk_mq_try_issue_directly(hctx, rq, cookie, false);
- rcu_read_unlock();
- } else {
- unsigned int srcu_idx;
+ int srcu_idx;
- might_sleep();
+ might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
- srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
- __blk_mq_try_issue_directly(hctx, rq, cookie, true);
- srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
- }
+ hctx_lock(hctx, &srcu_idx);
+ __blk_mq_try_issue_directly(hctx, rq, cookie);
+ hctx_unlock(hctx, srcu_idx);
}
static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
--
2.9.5
