blk-mq: Make it safe to quiesce and unquiesce from an interrupt handler

[karo-tx-linux.git] / include / linux / blk-mq.h

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index c47aa248c640bc5ea806d5112ce7f7b5fb6b7a46..23d32ff0b4629f6ae441ca6f697ee17f490fd9f7 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -39,8 +39,6 @@ struct blk_mq_hw_ctx {
        struct blk_mq_tags      *tags;
        struct blk_mq_tags      *sched_tags;
 
-       struct srcu_struct      queue_rq_srcu;
-
        unsigned long           queued;
        unsigned long           run;
 #define BLK_MQ_MAX_DISPATCH_ORDER      7
@@ -62,6 +60,9 @@ struct blk_mq_hw_ctx {
        struct dentry           *debugfs_dir;
        struct dentry           *sched_debugfs_dir;
 #endif
+
+       /* Must be the last member - see also blk_mq_hw_ctx_size(). */
+       struct srcu_struct      queue_rq_srcu[0];
 };
 
 struct blk_mq_tag_set {
@@ -87,7 +88,8 @@ struct blk_mq_queue_data {
        bool last;
 };
 
-typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *);
+typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *,
+               const struct blk_mq_queue_data *);
 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
@@ -142,6 +144,8 @@ struct blk_mq_ops {
        init_request_fn         *init_request;
        exit_request_fn         *exit_request;
        reinit_request_fn       *reinit_request;
+       /* Called from inside blk_get_request() */
+       void (*initialize_rq_fn)(struct request *rq);
 
        map_queues_fn           *map_queues;
 
@@ -155,10 +159,6 @@ struct blk_mq_ops {
 };
 
 enum {
-       BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
-       BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
-       BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
-
        BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
        BLK_MQ_F_TAG_SHARED     = 1 << 1,
        BLK_MQ_F_SG_MERGE       = 1 << 2,
@@ -204,10 +204,10 @@ enum {
        BLK_MQ_REQ_INTERNAL     = (1 << 2), /* allocate internal/sched tag */
 };
 
-struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
+struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
                unsigned int flags);
-struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int op,
-               unsigned int flags, unsigned int hctx_idx);
+struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
+               unsigned int op, unsigned int flags, unsigned int hctx_idx);
 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 
 enum {
@@ -230,15 +230,14 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
 
 int blk_mq_request_started(struct request *rq);
 void blk_mq_start_request(struct request *rq);
-void blk_mq_end_request(struct request *rq, int error);
-void __blk_mq_end_request(struct request *rq, int error);
+void blk_mq_end_request(struct request *rq, blk_status_t error);
+void __blk_mq_end_request(struct request *rq, blk_status_t error);
 
 void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
                                bool kick_requeue_list);
 void blk_mq_kick_requeue_list(struct request_queue *q);
 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
-void blk_mq_abort_requeue_list(struct request_queue *q);
 void blk_mq_complete_request(struct request *rq);
 
 bool blk_mq_queue_stopped(struct request_queue *q);
@@ -248,6 +247,8 @@ void blk_mq_stop_hw_queues(struct request_queue *q);
 void blk_mq_start_hw_queues(struct request_queue *q);
 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
+void blk_mq_quiesce_queue(struct request_queue *q);
+void blk_mq_unquiesce_queue(struct request_queue *q);
 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
@@ -265,6 +266,8 @@ int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);
 int blk_mq_map_queues(struct blk_mq_tag_set *set);
 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
 
+void blk_mq_quiesce_queue_nowait(struct request_queue *q);
+
 /*
  * Driver command data is immediately after the request. So subtract request
  * size to get back to the original request, add request size to get the PDU.