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authorMing Lei <ming.lei@redhat.com>2020-07-06 22:41:11 +0800
committerJens Axboe <axboe@kernel.dk>2020-07-08 16:06:42 -0600
commit568f2700657794b8258e72983ba508793a658942 (patch)
tree80372f8bdcf5994afeed2a73c503da510c624468
parent7bf137298cb73afdb8c5536e474f7ba71ab1c235 (diff)
blk-mq: centralise related handling into blk_mq_get_driver_tag
Move .nr_active update and request assignment into blk_mq_get_driver_tag(), all are good to do during getting driver tag. Meantime blk-flush related code is simplified and flush request needn't to update the request table manually any more. Signed-off-by: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-flush.c14
-rw-r--r--block/blk-mq-tag.h12
-rw-r--r--block/blk-mq.c31
-rw-r--r--block/blk.h5
4 files changed, 19 insertions, 43 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 15ae0155ec07..71c7f520e040 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -219,7 +219,6 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error)
struct request *rq, *n;
unsigned long flags = 0;
struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx);
- struct blk_mq_hw_ctx *hctx;
blk_account_io_flush(flush_rq);
@@ -235,13 +234,11 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error)
if (fq->rq_status != BLK_STS_OK)
error = fq->rq_status;
- hctx = flush_rq->mq_hctx;
if (!q->elevator) {
- blk_mq_tag_set_rq(hctx, flush_rq->tag, fq->orig_rq);
- flush_rq->tag = -1;
+ flush_rq->tag = BLK_MQ_NO_TAG;
} else {
blk_mq_put_driver_tag(flush_rq);
- flush_rq->internal_tag = -1;
+ flush_rq->internal_tag = BLK_MQ_NO_TAG;
}
running = &fq->flush_queue[fq->flush_running_idx];
@@ -316,13 +313,10 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
flush_rq->mq_ctx = first_rq->mq_ctx;
flush_rq->mq_hctx = first_rq->mq_hctx;
- if (!q->elevator) {
- fq->orig_rq = first_rq;
+ if (!q->elevator)
flush_rq->tag = first_rq->tag;
- blk_mq_tag_set_rq(flush_rq->mq_hctx, first_rq->tag, flush_rq);
- } else {
+ else
flush_rq->internal_tag = first_rq->internal_tag;
- }
flush_rq->cmd_flags = REQ_OP_FLUSH | REQ_PREFLUSH;
flush_rq->cmd_flags |= (flags & REQ_DRV) | (flags & REQ_FAILFAST_MASK);
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 3945c7f5b944..b1acac518c4e 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -101,18 +101,6 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
return atomic_read(&hctx->nr_active) < depth;
}
-/*
- * This helper should only be used for flush request to share tag
- * with the request cloned from, and both the two requests can't be
- * in flight at the same time. The caller has to make sure the tag
- * can't be freed.
- */
-static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
- unsigned int tag, struct request *rq)
-{
- hctx->tags->rqs[tag] = rq;
-}
-
static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,
unsigned int tag)
{
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 89c83fa97ba0..b6dd080d3962 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -277,26 +277,20 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
{
struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
struct request *rq = tags->static_rqs[tag];
- req_flags_t rq_flags = 0;
if (data->q->elevator) {
rq->tag = BLK_MQ_NO_TAG;
rq->internal_tag = tag;
} else {
- if (data->hctx->flags & BLK_MQ_F_TAG_SHARED) {
- rq_flags = RQF_MQ_INFLIGHT;
- atomic_inc(&data->hctx->nr_active);
- }
rq->tag = tag;
rq->internal_tag = BLK_MQ_NO_TAG;
- data->hctx->tags->rqs[rq->tag] = rq;
}
/* csd/requeue_work/fifo_time is initialized before use */
rq->q = data->q;
rq->mq_ctx = data->ctx;
rq->mq_hctx = data->hctx;
- rq->rq_flags = rq_flags;
+ rq->rq_flags = 0;
rq->cmd_flags = data->cmd_flags;
if (data->flags & BLK_MQ_REQ_PREEMPT)
rq->rq_flags |= RQF_PREEMPT;
@@ -1105,9 +1099,10 @@ static bool __blk_mq_get_driver_tag(struct request *rq)
{
struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
- bool shared = blk_mq_tag_busy(rq->mq_hctx);
int tag;
+ blk_mq_tag_busy(rq->mq_hctx);
+
if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
bt = &rq->mq_hctx->tags->breserved_tags;
tag_offset = 0;
@@ -1120,19 +1115,23 @@ static bool __blk_mq_get_driver_tag(struct request *rq)
return false;
rq->tag = tag + tag_offset;
- if (shared) {
- rq->rq_flags |= RQF_MQ_INFLIGHT;
- atomic_inc(&rq->mq_hctx->nr_active);
- }
- rq->mq_hctx->tags->rqs[rq->tag] = rq;
return true;
}
static bool blk_mq_get_driver_tag(struct request *rq)
{
- if (rq->tag != BLK_MQ_NO_TAG)
- return true;
- return __blk_mq_get_driver_tag(rq);
+ struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
+
+ if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_get_driver_tag(rq))
+ return false;
+
+ if ((hctx->flags & BLK_MQ_F_TAG_SHARED) &&
+ !(rq->rq_flags & RQF_MQ_INFLIGHT)) {
+ rq->rq_flags |= RQF_MQ_INFLIGHT;
+ atomic_inc(&hctx->nr_active);
+ }
+ hctx->tags->rqs[rq->tag] = rq;
+ return true;
}
static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
diff --git a/block/blk.h b/block/blk.h
index 94f7c084f68f..9dcf51c94096 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -25,11 +25,6 @@ struct blk_flush_queue {
struct list_head flush_data_in_flight;
struct request *flush_rq;
- /*
- * flush_rq shares tag with this rq, both can't be active
- * at the same time
- */
- struct request *orig_rq;
struct lock_class_key key;
spinlock_t mq_flush_lock;
};