blk-mq: add a flags parameter to blk_mq_alloc_request

We already have the reserved flag, and a nowait flag awkwardly encoded as
a gfp_t.  Add a real flags argument to make the scheme more extensible and
allow for a nicer calling convention.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

4 files changed, 23 insertions, 30 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index c88a946eca49..5ec996036e16 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -630,7 +630,7 @@ struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
 }
 EXPORT_SYMBOL(blk_alloc_queue);
 
-int blk_queue_enter(struct request_queue *q, gfp_t gfp)
+int blk_queue_enter(struct request_queue *q, bool nowait)
 {
         while (true) {
                 int ret;
@@ -638,7 +638,7 @@ int blk_queue_enter(struct request_queue *q, gfp_t gfp)
                 if (percpu_ref_tryget_live(&q->q_usage_counter))
                         return 0;
 
-                if (!gfpflags_allow_blocking(gfp))
+                if (nowait)
                         return -EBUSY;
 
                 ret = wait_event_interruptible(q->mq_freeze_wq,
@@ -1276,7 +1276,9 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
 struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
 {
         if (q->mq_ops)
-                return blk_mq_alloc_request(q, rw, gfp_mask, false);
+                return blk_mq_alloc_request(q, rw,
+                        (gfp_mask & __GFP_DIRECT_RECLAIM) ?
+                                0 : BLK_MQ_REQ_NOWAIT);
         else
                 return blk_old_get_request(q, rw, gfp_mask);
 }
@@ -2044,8 +2046,7 @@ blk_qc_t generic_make_request(struct bio *bio)
         do {
                 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 
-                if (likely(blk_queue_enter(q, __GFP_DIRECT_RECLAIM) == 0)) {
-
+                if (likely(blk_queue_enter(q, false) == 0)) {
                         ret = q->make_request_fn(q, bio);
 
                         blk_queue_exit(q);
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index a07ca3488d96..abdbb47405cb 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -268,7 +268,7 @@ static int bt_get(struct blk_mq_alloc_data *data,
         if (tag != -1)
                 return tag;
 
-        if (!gfpflags_allow_blocking(data->gfp))
+        if (data->flags & BLK_MQ_REQ_NOWAIT)
                 return -1;
 
         bs = bt_wait_ptr(bt, hctx);
@@ -303,7 +303,7 @@ static int bt_get(struct blk_mq_alloc_data *data,
                 data->ctx = blk_mq_get_ctx(data->q);
                 data->hctx = data->q->mq_ops->map_queue(data->q,
                                 data->ctx->cpu);
-                if (data->reserved) {
+                if (data->flags & BLK_MQ_REQ_RESERVED) {
                         bt = &data->hctx->tags->breserved_tags;
                 } else {
                         last_tag = &data->ctx->last_tag;
@@ -349,10 +349,9 @@ static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data)
 
 unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
 {
-        if (!data->reserved)
-                return __blk_mq_get_tag(data);
-
-        return __blk_mq_get_reserved_tag(data);
+        if (data->flags & BLK_MQ_REQ_RESERVED)
+                return __blk_mq_get_reserved_tag(data);
+        return __blk_mq_get_tag(data);
 }
 
 static struct bt_wait_state *bt_wake_ptr(struct blk_mq_bitmap_tags *bt)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6d6f8feb48c0..93a4e1956915 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -229,8 +229,8 @@ __blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw)
         return NULL;
 }
 
-struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
-                bool reserved)
+struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
+                unsigned int flags)
 {
         struct blk_mq_ctx *ctx;
         struct blk_mq_hw_ctx *hctx;
@@ -238,24 +238,22 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
         struct blk_mq_alloc_data alloc_data;
         int ret;
 
-        ret = blk_queue_enter(q, gfp);
+        ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT);
         if (ret)
                 return ERR_PTR(ret);
 
         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_DIRECT_RECLAIM,
-                        reserved, ctx, hctx);
+        blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
 
         rq = __blk_mq_alloc_request(&alloc_data, rw);
-        if (!rq && (gfp & __GFP_DIRECT_RECLAIM)) {
+        if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) {
                 __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);
-                blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx,
-                                hctx);
+                blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
                 rq =  __blk_mq_alloc_request(&alloc_data, rw);
                 ctx = alloc_data.ctx;
         }
@@ -1175,8 +1173,7 @@ static struct request *blk_mq_map_request(struct request_queue *q,
                 rw |= REQ_SYNC;
 
         trace_block_getrq(q, bio, rw);
-        blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx,
-                        hctx);
+        blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx);
         rq = __blk_mq_alloc_request(&alloc_data, rw);
         if (unlikely(!rq)) {
                 __blk_mq_run_hw_queue(hctx);
@@ -1185,8 +1182,7 @@ 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);
-                blk_mq_set_alloc_data(&alloc_data, q,
-                                __GFP_RECLAIM|__GFP_HIGH, false, ctx, hctx);
+                blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
                 rq = __blk_mq_alloc_request(&alloc_data, rw);
                 ctx = alloc_data.ctx;
                 hctx = alloc_data.hctx;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 713820b47b31..eaede8e45c9c 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -96,8 +96,7 @@ static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 struct blk_mq_alloc_data {
         /* input parameter */
         struct request_queue *q;
-        gfp_t gfp;
-        bool reserved;
+        unsigned int flags;
 
         /* input & output parameter */
         struct blk_mq_ctx *ctx;
@@ -105,13 +104,11 @@ struct blk_mq_alloc_data {
 };
 
 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
-                struct request_queue *q, gfp_t gfp, bool reserved,
-                struct blk_mq_ctx *ctx,
-                struct blk_mq_hw_ctx *hctx)
+                struct request_queue *q, unsigned int flags,
+                struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
 {
         data->q = q;
-        data->gfp = gfp;
-        data->reserved = reserved;
+        data->flags = flags;
         data->ctx = ctx;
         data->hctx = hctx;
 }