#ifndef BLK_INTERNAL_H #define BLK_INTERNAL_H #include <linux/idr.h> /* Amount of time in which a process may batch requests */ #define BLK_BATCH_TIME (HZ/50UL) /* Number of requests a "batching" process may submit */ #define BLK_BATCH_REQ 32 extern struct kmem_cache *blk_requestq_cachep; extern struct kobj_type blk_queue_ktype; extern struct ida blk_queue_ida; static inline void __blk_get_queue(struct request_queue *q) { kobject_get(&q->kobj); } void init_request_from_bio(struct request *req, struct bio *bio); void blk_rq_bio_prep(struct request_queue *q, struct request *rq, struct bio *bio); int blk_rq_append_bio(struct request_queue *q, struct request *rq, struct bio *bio); void blk_drain_queue(struct request_queue *q, bool drain_all); void blk_dequeue_request(struct request *rq); void __blk_queue_free_tags(struct request_queue *q); bool __blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes); void blk_rq_timed_out_timer(unsigned long data); void blk_delete_timer(struct request *); void blk_add_timer(struct request *); void __generic_unplug_device(struct request_queue *); /* * Internal atomic flags for request handling */ enum rq_atomic_flags { REQ_ATOM_COMPLETE = 0, }; /* * EH timer and IO completion will both attempt to 'grab' the request, make * sure that only one of them succeeds */ static inline int blk_mark_rq_complete(struct request *rq) { return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); } static inline void blk_clear_rq_complete(struct request *rq) { clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); } /* * Internal elevator interface */ #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) void blk_insert_flush(struct request *rq); void blk_abort_flushes(struct request_queue *q); static inline struct request *__elv_next_request(struct request_queue *q) { struct request *rq; while (1) { if (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); return rq; } /* * Flush request is running and flush request isn't queueable * in the drive, we can hold the queue till flush request is * finished. Even we don't do this, driver can't dispatch next * requests and will requeue them. And this can improve * throughput too. For example, we have request flush1, write1, * flush 2. flush1 is dispatched, then queue is hold, write1 * isn't inserted to queue. After flush1 is finished, flush2 * will be dispatched. Since disk cache is already clean, * flush2 will be finished very soon, so looks like flush2 is * folded to flush1. * Since the queue is hold, a flag is set to indicate the queue * should be restarted later. Please see flush_end_io() for * details. */ if (q->flush_pending_idx != q->flush_running_idx && !queue_flush_queueable(q)) { q->flush_queue_delayed = 1; return NULL; } if (unlikely(blk_queue_dead(q)) || !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) return NULL; } } static inline void elv_activate_rq(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_activate_req_fn) e->type->ops.elevator_activate_req_fn(q, rq); } static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_deactivate_req_fn) e->type->ops.elevator_deactivate_req_fn(q, rq); } #ifdef CONFIG_FAIL_IO_TIMEOUT int blk_should_fake_timeout(struct request_queue *); ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); ssize_t part_timeout_store(struct device *, struct device_attribute *, const char *, size_t); #else static inline int blk_should_fake_timeout(struct request_queue *q) { return 0; } #endif int ll_back_merge_fn(struct request_queue *q, struct request *req, struct bio *bio); int ll_front_merge_fn(struct request_queue *q, struct request *req, struct bio *bio); int attempt_back_merge(struct request_queue *q, struct request *rq); int attempt_front_merge(struct request_queue *q, struct request *rq); int blk_attempt_req_merge(struct request_queue *q, struct request *rq, struct request *next); void blk_recalc_rq_segments(struct request *rq); void blk_rq_set_mixed_merge(struct request *rq); bool blk_rq_merge_ok(struct request *rq, struct bio *bio); int blk_try_merge(struct request *rq, struct bio *bio); void blk_queue_congestion_threshold(struct request_queue *q); int blk_dev_init(void); void elv_quiesce_start(struct request_queue *q); void elv_quiesce_end(struct request_queue *q); /* * Return the threshold (number of used requests) at which the queue is * considered to be congested. It include a little hysteresis to keep the * context switch rate down. */ static inline int queue_congestion_on_threshold(struct request_queue *q) { return q->nr_congestion_on; } /* * The threshold at which a queue is considered to be uncongested */ static inline int queue_congestion_off_threshold(struct request_queue *q) { return q->nr_congestion_off; } /* * Contribute to IO statistics IFF: * * a) it's attached to a gendisk, and * b) the queue had IO stats enabled when this request was started, and * c) it's a file system request or a discard request */ static inline int blk_do_io_stat(struct request *rq) { return rq->rq_disk && (rq->cmd_flags & REQ_IO_STAT) && (rq->cmd_type == REQ_TYPE_FS || (rq->cmd_flags & REQ_DISCARD)); } /* * Internal io_context interface */ void get_io_context(struct io_context *ioc); struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask); void ioc_clear_queue(struct request_queue *q); void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_mask, int node); /** * create_io_context - try to create task->io_context * @task: target task * @gfp_mask: allocation mask * @node: allocation node * * If @task->io_context is %NULL, allocate a new io_context and install it. * Returns the current @task->io_context which may be %NULL if allocation * failed. * * Note that this function can't be called with IRQ disabled because * task_lock which protects @task->io_context is IRQ-unsafe. */ static inline struct io_context *create_io_context(struct task_struct *task, gfp_t gfp_mask, int node) { WARN_ON_ONCE(irqs_disabled()); if (unlikely(!task->io_context)) create_io_context_slowpath(task, gfp_mask, node); return task->io_context; } /* * Internal throttling interface */ #ifdef CONFIG_BLK_DEV_THROTTLING extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); extern void blk_throtl_drain(struct request_queue *q); extern int blk_throtl_init(struct request_queue *q); extern void blk_throtl_exit(struct request_queue *q); extern void blk_throtl_release(struct request_queue *q); #else /* CONFIG_BLK_DEV_THROTTLING */ static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) { return false; } static inline void blk_throtl_drain(struct request_queue *q) { } static inline int blk_throtl_init(struct request_queue *q) { return 0; } static inline void blk_throtl_exit(struct request_queue *q) { } static inline void blk_throtl_release(struct request_queue *q) { } #endif /* CONFIG_BLK_DEV_THROTTLING */ #endif /* BLK_INTERNAL_H */