block: prepare for multiple request_lists

Request allocation is about to be made per-blkg meaning that there'll
be multiple request lists.

* Make queue full state per request_list.  blk_*queue_full() functions
  are renamed to blk_*rl_full() and takes @rl instead of @q.

* Rename blk_init_free_list() to blk_init_rl() and make it take @rl
  instead of @q.  Also add @gfp_mask parameter.

* Add blk_exit_rl() instead of destroying rl directly from
  blk_release_queue().

* Add request_list->q and make request alloc/free functions -
  blk_free_request(), [__]freed_request(), __get_request() - take @rl
  instead of @q.

This patch doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 18 insertions, 14 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7e44ed93f84b..f2385ee7c7b2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -46,7 +46,12 @@ struct blkcg_gq;
 struct request;
 typedef void (rq_end_io_fn)(struct request *, int);
 
+#define BLK_RL_SYNCFULL         (1U << 0)
+#define BLK_RL_ASYNCFULL        (1U << 1)
+
 struct request_list {
+        struct request_queue    *q;     /* the queue this rl belongs to */
+
         /*
          * count[], starved[], and wait[] are indexed by
          * BLK_RW_SYNC/BLK_RW_ASYNC
@@ -55,6 +60,7 @@ struct request_list {
         int                     starved[2];
         mempool_t               *rq_pool;
         wait_queue_head_t       wait[2];
+        unsigned int            flags;
 };
 
 /*
@@ -562,27 +568,25 @@ static inline bool rq_is_sync(struct request *rq)
         return rw_is_sync(rq->cmd_flags);
 }
 
-static inline int blk_queue_full(struct request_queue *q, int sync)
+static inline bool blk_rl_full(struct request_list *rl, bool sync)
 {
-        if (sync)
-                return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
-        return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
+        unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
+
+        return rl->flags & flag;
 }
 
-static inline void blk_set_queue_full(struct request_queue *q, int sync)
+static inline void blk_set_rl_full(struct request_list *rl, bool sync)
 {
-        if (sync)
-                queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
-        else
-                queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
+        unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
+
+        rl->flags |= flag;
 }
 
-static inline void blk_clear_queue_full(struct request_queue *q, int sync)
+static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
 {
-        if (sync)
-                queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
-        else
-                queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
+        unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
+
+        rl->flags &= ~flag;
 }