Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma

[cascardo/linux.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0f5879c..4e4cd62 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -33,28 +33,6 @@ static LIST_HEAD(all_q_list);
 
 static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);
 
-static struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
-                                          unsigned int cpu)
-{
-       return per_cpu_ptr(q->queue_ctx, cpu);
-}
-
-/*
- * This assumes per-cpu software queueing queues. They could be per-node
- * as well, for instance. For now this is hardcoded as-is. Note that we don't
- * care about preemption, since we know the ctx's are persistent. This does
- * mean that we can't rely on ctx always matching the currently running CPU.
- */
-static struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
-{
-       return __blk_mq_get_ctx(q, get_cpu());
-}
-
-static void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
-{
-       put_cpu();
-}
-
 /*
  * Check if any of the ctx's have pending work in this hardware queue
  */
@@ -232,24 +210,23 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 }
 
 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)
+__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw)
 {
        struct request *rq;
        unsigned int tag;
 
-       tag = blk_mq_get_tag(hctx, &ctx->last_tag, gfp, reserved);
+       tag = blk_mq_get_tag(data);
        if (tag != BLK_MQ_TAG_FAIL) {
-               rq = hctx->tags->rqs[tag];
+               rq = data->hctx->tags->rqs[tag];
 
                rq->cmd_flags = 0;
-               if (blk_mq_tag_busy(hctx)) {
+               if (blk_mq_tag_busy(data->hctx)) {
                        rq->cmd_flags = REQ_MQ_INFLIGHT;
-                       atomic_inc(&hctx->nr_active);
+                       atomic_inc(&data->hctx->nr_active);
                }
 
                rq->tag = tag;
-               blk_mq_rq_ctx_init(q, ctx, rq, rw);
+               blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw);
                return rq;
        }
 
@@ -262,22 +239,27 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
        struct blk_mq_ctx *ctx;
        struct blk_mq_hw_ctx *hctx;
        struct request *rq;
+       struct blk_mq_alloc_data alloc_data;
 
        if (blk_mq_queue_enter(q))
                return NULL;
 
        ctx = blk_mq_get_ctx(q);
        hctx = q->mq_ops->map_queue(q, ctx->cpu);
+       blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT,
+                       reserved, ctx, hctx);
 
-       rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp & ~__GFP_WAIT,
-                                   reserved);
+       rq = __blk_mq_alloc_request(&alloc_data, rw);
        if (!rq && (gfp & __GFP_WAIT)) {
                __blk_mq_run_hw_queue(hctx);
                blk_mq_put_ctx(ctx);
 
                ctx = blk_mq_get_ctx(q);
                hctx = q->mq_ops->map_queue(q, ctx->cpu);
-               rq =  __blk_mq_alloc_request(q, hctx, ctx, rw, gfp, reserved);
+               blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx,
+                               hctx);
+               rq =  __blk_mq_alloc_request(&alloc_data, rw);
+               ctx = alloc_data.ctx;
        }
        blk_mq_put_ctx(ctx);
        return rq;
@@ -547,15 +529,20 @@ void blk_mq_kick_requeue_list(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_mq_kick_requeue_list);
 
-struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx, unsigned int tag)
+static inline bool is_flush_request(struct request *rq, unsigned int tag)
 {
-       struct request_queue *q = hctx->queue;
+       return ((rq->cmd_flags & REQ_FLUSH_SEQ) &&
+                       rq->q->flush_rq->tag == tag);
+}
+
+struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
+{
+       struct request *rq = tags->rqs[tag];
 
-       if ((q->flush_rq->cmd_flags & REQ_FLUSH_SEQ) &&
-           q->flush_rq->tag == tag)
-               return q->flush_rq;
+       if (!is_flush_request(rq, tag))
+               return rq;
 
-       return hctx->tags->rqs[tag];
+       return rq->q->flush_rq;
 }
 EXPORT_SYMBOL(blk_mq_tag_to_rq);
 
@@ -584,7 +571,7 @@ static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
                if (tag >= hctx->tags->nr_tags)
                        break;
 
-               rq = blk_mq_tag_to_rq(hctx, tag++);
+               rq = blk_mq_tag_to_rq(hctx->tags, tag++);
                if (rq->q != hctx->queue)
                        continue;
                if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
@@ -1158,6 +1145,7 @@ static struct request *blk_mq_map_request(struct request_queue *q,
        struct blk_mq_ctx *ctx;
        struct request *rq;
        int rw = bio_data_dir(bio);
+       struct blk_mq_alloc_data alloc_data;
 
        if (unlikely(blk_mq_queue_enter(q))) {
                bio_endio(bio, -EIO);
@@ -1171,7 +1159,9 @@ 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(q, hctx, ctx, rw, GFP_ATOMIC, false);
+       blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx,
+                       hctx);
+       rq = __blk_mq_alloc_request(&alloc_data, rw);
        if (unlikely(!rq)) {
                __blk_mq_run_hw_queue(hctx);
                blk_mq_put_ctx(ctx);
@@ -1179,8 +1169,11 @@ static struct request *blk_mq_map_request(struct request_queue *q,
 
                ctx = blk_mq_get_ctx(q);
                hctx = q->mq_ops->map_queue(q, ctx->cpu);
-               rq = __blk_mq_alloc_request(q, hctx, ctx, rw,
-                                           __GFP_WAIT|GFP_ATOMIC, false);
+               blk_mq_set_alloc_data(&alloc_data, q,
+                               __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx);
+               rq = __blk_mq_alloc_request(&alloc_data, rw);
+               ctx = alloc_data.ctx;
+               hctx = alloc_data.hctx;
        }
 
        hctx->queued++;
@@ -1288,6 +1281,8 @@ static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
                return;
 
        rq = blk_mq_map_request(q, bio, &data);
+       if (unlikely(!rq))
+               return;
 
        if (unlikely(is_flush_fua)) {
                blk_mq_bio_to_request(rq, bio);
@@ -1562,6 +1557,8 @@ static void blk_mq_exit_hw_queues(struct request_queue *q,
                if (i == nr_queue)
                        break;
 
+               blk_mq_tag_idle(hctx);
+
                if (set->ops->exit_hctx)
                        set->ops->exit_hctx(hctx, i);
 
@@ -1779,7 +1776,7 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 {
        struct blk_mq_hw_ctx **hctxs;
-       struct blk_mq_ctx *ctx;
+       struct blk_mq_ctx __percpu *ctx;
        struct request_queue *q;
        unsigned int *map;
        int i;