block,scsi: fixup blk_get_request dead queue scenarios

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5189cb1e478a6b283609006364c01f9f8e31d082..940aa8a34b70b656d5babca89ad2fd7ac5ad2849 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -218,9 +218,11 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
        struct blk_mq_hw_ctx *hctx;
        struct request *rq;
        struct blk_mq_alloc_data alloc_data;
+       int ret;
 
-       if (blk_mq_queue_enter(q))
-               return NULL;
+       ret = blk_mq_queue_enter(q);
+       if (ret)
+               return ERR_PTR(ret);
 
        ctx = blk_mq_get_ctx(q);
        hctx = q->mq_ops->map_queue(q, ctx->cpu);
@@ -240,6 +242,8 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
                ctx = alloc_data.ctx;
        }
        blk_mq_put_ctx(ctx);
+       if (!rq)
+               return ERR_PTR(-EWOULDBLOCK);
        return rq;
 }
 EXPORT_SYMBOL(blk_mq_alloc_request);