diff options
Diffstat (limited to 'block/blk-mq.h')
| -rw-r--r-- | block/blk-mq.h | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/block/blk-mq.h b/block/blk-mq.h index 6c7c3ff5bf62..88c558f71819 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -27,6 +27,20 @@ struct blk_mq_ctx { struct kobject kobj; } ____cacheline_aligned_in_smp; +/* + * Bits for request->gstate. The lower two bits carry MQ_RQ_* state value + * and the upper bits the generation number. + */ +enum mq_rq_state { + MQ_RQ_IDLE = 0, + MQ_RQ_IN_FLIGHT = 1, + MQ_RQ_COMPLETE = 2, + + MQ_RQ_STATE_BITS = 2, + MQ_RQ_STATE_MASK = (1 << MQ_RQ_STATE_BITS) - 1, + MQ_RQ_GEN_INC = 1 << MQ_RQ_STATE_BITS, +}; + void blk_mq_freeze_queue(struct request_queue *q); void blk_mq_free_queue(struct request_queue *q); int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); @@ -60,6 +74,9 @@ void blk_mq_request_bypass_insert(struct request *rq, bool run_queue); void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct list_head *list); +/* Used by blk_insert_cloned_request() to issue request directly */ +blk_status_t blk_mq_request_issue_directly(struct request *rq); + /* * CPU -> queue mappings */ @@ -81,10 +98,41 @@ extern int blk_mq_sysfs_register(struct request_queue *q); extern void blk_mq_sysfs_unregister(struct request_queue *q); extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); -extern void blk_mq_rq_timed_out(struct request *req, bool reserved); - void blk_mq_release(struct request_queue *q); +/** + * blk_mq_rq_state() - read the current MQ_RQ_* state of a request + * @rq: target request. + */ +static inline int blk_mq_rq_state(struct request *rq) +{ + return READ_ONCE(rq->gstate) & MQ_RQ_STATE_MASK; +} + +/** + * blk_mq_rq_update_state() - set the current MQ_RQ_* state of a request + * @rq: target request. + * @state: new state to set. + * + * Set @rq's state to @state. The caller is responsible for ensuring that + * there are no other updaters. A request can transition into IN_FLIGHT + * only from IDLE and doing so increments the generation number. + */ +static inline void blk_mq_rq_update_state(struct request *rq, + enum mq_rq_state state) +{ + u64 old_val = READ_ONCE(rq->gstate); + u64 new_val = (old_val & ~MQ_RQ_STATE_MASK) | state; + + if (state == MQ_RQ_IN_FLIGHT) { + WARN_ON_ONCE((old_val & MQ_RQ_STATE_MASK) != MQ_RQ_IDLE); + new_val += MQ_RQ_GEN_INC; + } + + /* avoid exposing interim values */ + WRITE_ONCE(rq->gstate, new_val); +} + static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, unsigned int cpu) { |