#ifndef BLK_INTERNAL_H #define BLK_INTERNAL_H #include #include #include "blk-mq.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 /* Max future timer expiry for timeouts */ #define BLK_MAX_TIMEOUT (5 * HZ) #ifdef CONFIG_DEBUG_FS extern struct dentry *blk_debugfs_root; #endif struct blk_flush_queue { unsigned int flush_queue_delayed:1; unsigned int flush_pending_idx:1; unsigned int flush_running_idx:1; unsigned long flush_pending_since; struct list_head flush_queue[2]; struct list_head flush_data_in_flight; struct request *flush_rq; /* * flush_rq shares tag with this rq, both can't be active * at the same time */ struct request *orig_rq; spinlock_t mq_flush_lock; }; extern struct kmem_cache *blk_requestq_cachep; extern struct kmem_cache *request_cachep; extern struct kobj_type blk_queue_ktype; extern struct ida blk_queue_ida; static inline struct blk_flush_queue *blk_get_flush_queue( struct request_queue *q, struct blk_mq_ctx *ctx) { if (q->mq_ops) return blk_mq_map_queue(q, ctx->cpu)->fq; return q->fq; } static inline void __blk_get_queue(struct request_queue *q) { kobject_get(&q->kobj); } struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, int node, int cmd_size); void blk_free_flush_queue(struct blk_flush_queue *q); int blk_init_rl(struct request_list *rl, struct request_queue *q, gfp_t gfp_mask); void blk_exit_rl(struct request_list *rl); 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); void blk_queue_bypass_start(struct request_queue *q); void blk_queue_bypass_end(struct request_queue *q); void blk_dequeue_request(struct request *rq); void __blk_queue_free_tags(struct request_queue *q); void blk_freeze_queue(struct request_queue *q); static inline void blk_queue_enter_live(struct request_queue *q) { /* * Given that running in generic_make_request() context * guarantees that a live reference against q_usage_counter has * been established, further references under that same context * need not check that the queue has been frozen (marked dead). */ percpu_ref_get(&q->q_usage_counter); } #ifdef CONFIG_BLK_DEV_INTEGRITY void blk_flush_integrity(void); #else static inline void blk_flush_integrity(void) { } #endif void blk_timeout_work(struct work_struct *work); unsigned long blk_rq_timeout(unsigned long timeout); void blk_add_timer(struct request *req); void blk_delete_timer(struct request *); bool bio_attempt_front_merge(struct request_queue *q, struct request *req, struct bio *bio); bool bio_attempt_back_merge(struct request_queue *q, struct request *req, struct bio *bio); bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, struct bio *bio); bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int *request_count, struct request **same_queue_rq); unsigned int blk_plug_queued_count(struct request_queue *q); void blk_account_io_start(struct request *req, bool new_io); void blk_account_io_completion(struct request *req, unsigned int bytes); void blk_account_io_done(struct request *req); /* * Internal atomic flags for request handling */ enum rq_atomic_flags { REQ_ATOM_COMPLETE = 0, REQ_ATOM_STARTED, REQ_ATOM_POLL_SLEPT, }; /* * 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) ((rq)->rq_flags & RQF_HASHED) void blk_insert_flush(struct request *rq); static inline struct request *__elv_next_request(struct request_queue *q) { struct request *rq; struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); 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 (fq->flush_pending_idx != fq->flush_running_idx && !queue_flush_queueable(q)) { fq->flush_queue_delayed = 1; return NULL; } if (unlikely(blk_queue_bypass(q)) || !q->elevator->type->ops.sq.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.sq.elevator_activate_req_fn) e->type->ops.sq.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.sq.elevator_deactivate_req_fn) e->type->ops.sq.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); struct request *attempt_back_merge(struct request_queue *q, struct request *rq); struct request *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); enum elv_merge blk_try_merge(struct request *rq, struct bio *bio); void blk_queue_congestion_threshold(struct request_queue *q); int blk_dev_init(void); /* * 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; } extern int blk_update_nr_requests(struct request_queue *, unsigned int); /* * 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 */ static inline int blk_do_io_stat(struct request *rq) { return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq); } static inline void req_set_nomerge(struct request_queue *q, struct request *req) { req->cmd_flags |= REQ_NOMERGE; if (req == q->last_merge) q->last_merge = NULL; } /* * 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 io_context *ioc, struct request_queue *q, gfp_t gfp_mask); void ioc_clear_queue(struct request_queue *q); int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); /** * rq_ioc - determine io_context for request allocation * @bio: request being allocated is for this bio (can be %NULL) * * Determine io_context to use for request allocation for @bio. May return * %NULL if %current->io_context doesn't exist. */ static inline struct io_context *rq_ioc(struct bio *bio) { #ifdef CONFIG_BLK_CGROUP if (bio && bio->bi_ioc) return bio->bi_ioc; #endif return current->io_context; } /** * create_io_context - try to create task->io_context * @gfp_mask: allocation mask * @node: allocation node * * If %current->io_context is %NULL, allocate a new io_context and install * it. Returns the current %current->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 %current->io_context is IRQ-unsafe. */ static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) { WARN_ON_ONCE(irqs_disabled()); if (unlikely(!current->io_context)) create_task_io_context(current, gfp_mask, node); return current->io_context; } /* * Internal throttling interface */ #ifdef CONFIG_BLK_DEV_THROTTLING 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_register_queue(struct request_queue *q); #else /* CONFIG_BLK_DEV_THROTTLING */ 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_register_queue(struct request_queue *q) { } #endif /* CONFIG_BLK_DEV_THROTTLING */ #ifdef CONFIG_BLK_DEV_THROTTLING_LOW extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page); extern ssize_t blk_throtl_sample_time_store(struct request_queue *q, const char *page, size_t count); extern void blk_throtl_bio_endio(struct bio *bio); extern void blk_throtl_stat_add(struct request *rq, u64 time); #else static inline void blk_throtl_bio_endio(struct bio *bio) { } static inline void blk_throtl_stat_add(struct request *rq, u64 time) { } #endif #endif /* BLK_INTERNAL_H */