blk-mq: fix schedule from atomic context

[linux-2.6-block.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index b9230c522c6bc5d2d79d869de5853f96657b1412..43eb3156e1107e8946d4a8d2a2c7e3c1e3b0bea9 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -210,24 +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;
        }
 
@@ -240,22 +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;
@@ -1136,6 +1140,7 @@ 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);
@@ -1149,7 +1154,9 @@ 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);
@@ -1157,8 +1164,11 @@ 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++;