[PATCH 2/5] blk-mq: initialize request in __blk_mq_alloc_request

From: Christoph Hellwig
Date: Tue May 27 2014 - 14:58:56 EST


Both callers if __blk_mq_alloc_request want to initialize the request, so
lift it into the common path.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-mq.c | 62 +++++++++++++++++++++++++++-----------------------------
1 file changed, 30 insertions(+), 32 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f8f84e2..848b3b6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -92,30 +92,6 @@ static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
}

-static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx,
- gfp_t gfp, bool reserved)
-{
- struct request *rq;
- unsigned int tag;
-
- tag = blk_mq_get_tag(hctx, &ctx->last_tag, gfp, reserved);
- if (tag != BLK_MQ_TAG_FAIL) {
- rq = hctx->tags->rqs[tag];
-
- rq->cmd_flags = 0;
- if (blk_mq_tag_busy(hctx)) {
- rq->cmd_flags = REQ_MQ_INFLIGHT;
- atomic_inc(&hctx->nr_active);
- }
-
- rq->tag = tag;
- return rq;
- }
-
- return NULL;
-}
-
static int blk_mq_queue_enter(struct request_queue *q)
{
int ret;
@@ -263,6 +239,32 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
}

+static struct request *
+__blk_mq_alloc_request(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx, int rw, gfp_t gfp, bool reserved)
+{
+ struct request *rq;
+ unsigned int tag;
+
+ tag = blk_mq_get_tag(hctx, &ctx->last_tag, gfp, reserved);
+ if (tag != BLK_MQ_TAG_FAIL) {
+ rq = hctx->tags->rqs[tag];
+
+ rq->cmd_flags = 0;
+ if (blk_mq_tag_busy(hctx)) {
+ rq->cmd_flags = REQ_MQ_INFLIGHT;
+ atomic_inc(&hctx->nr_active);
+ }
+
+ rq->tag = tag;
+ blk_mq_rq_ctx_init(q, ctx, rq, rw);
+ return rq;
+ }
+
+ return NULL;
+}
+
+
static struct request *blk_mq_alloc_request_pinned(struct request_queue *q,
int rw, gfp_t gfp,
bool reserved)
@@ -273,12 +275,10 @@ static struct request *blk_mq_alloc_request_pinned(struct request_queue *q,
struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu);

- rq = __blk_mq_alloc_request(hctx, ctx, gfp & ~__GFP_WAIT,
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp & ~__GFP_WAIT,
reserved);
- if (rq) {
- blk_mq_rq_ctx_init(q, ctx, rq, rw);
+ if (rq)
break;
- }

if (gfp & __GFP_WAIT) {
__blk_mq_run_hw_queue(hctx);
@@ -1114,10 +1114,8 @@ static struct request *blk_mq_map_request(struct request_queue *q,
rw |= REQ_SYNC;

trace_block_getrq(q, bio, rw);
- rq = __blk_mq_alloc_request(hctx, ctx, GFP_ATOMIC, false);
- if (likely(rq))
- blk_mq_rq_ctx_init(q, ctx, rq, rw);
- else {
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw, GFP_ATOMIC, false);
+ if (unlikely(!rq)) {
blk_mq_put_ctx(ctx);
trace_block_sleeprq(q, bio, rw);
rq = blk_mq_alloc_request_pinned(q, rw, __GFP_WAIT|GFP_ATOMIC,
--
1.7.10.4

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