3bce016a4c
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
353 lines
11 KiB
C
353 lines
11 KiB
C
#ifndef BLK_INTERNAL_H
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#define BLK_INTERNAL_H
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#include <linux/idr.h>
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#include <linux/blk-mq.h>
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#include "blk-mq.h"
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/* Amount of time in which a process may batch requests */
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#define BLK_BATCH_TIME (HZ/50UL)
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/* Number of requests a "batching" process may submit */
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#define BLK_BATCH_REQ 32
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/* Max future timer expiry for timeouts */
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#define BLK_MAX_TIMEOUT (5 * HZ)
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#ifdef CONFIG_DEBUG_FS
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extern struct dentry *blk_debugfs_root;
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#endif
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struct blk_flush_queue {
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unsigned int flush_queue_delayed:1;
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unsigned int flush_pending_idx:1;
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unsigned int flush_running_idx:1;
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unsigned long flush_pending_since;
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struct list_head flush_queue[2];
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struct list_head flush_data_in_flight;
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struct request *flush_rq;
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/*
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* flush_rq shares tag with this rq, both can't be active
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* at the same time
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*/
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struct request *orig_rq;
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spinlock_t mq_flush_lock;
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};
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extern struct kmem_cache *blk_requestq_cachep;
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extern struct kmem_cache *request_cachep;
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extern struct kobj_type blk_queue_ktype;
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extern struct ida blk_queue_ida;
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static inline struct blk_flush_queue *blk_get_flush_queue(
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struct request_queue *q, struct blk_mq_ctx *ctx)
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{
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if (q->mq_ops)
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return blk_mq_map_queue(q, ctx->cpu)->fq;
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return q->fq;
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}
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static inline void __blk_get_queue(struct request_queue *q)
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{
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kobject_get(&q->kobj);
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}
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struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
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int node, int cmd_size);
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void blk_free_flush_queue(struct blk_flush_queue *q);
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int blk_init_rl(struct request_list *rl, struct request_queue *q,
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gfp_t gfp_mask);
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void blk_exit_rl(struct request_queue *q, struct request_list *rl);
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void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
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struct bio *bio);
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void blk_queue_bypass_start(struct request_queue *q);
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void blk_queue_bypass_end(struct request_queue *q);
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void blk_dequeue_request(struct request *rq);
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void __blk_queue_free_tags(struct request_queue *q);
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void blk_freeze_queue(struct request_queue *q);
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static inline void blk_queue_enter_live(struct request_queue *q)
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{
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/*
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* Given that running in generic_make_request() context
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* guarantees that a live reference against q_usage_counter has
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* been established, further references under that same context
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* need not check that the queue has been frozen (marked dead).
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*/
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percpu_ref_get(&q->q_usage_counter);
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}
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#ifdef CONFIG_BLK_DEV_INTEGRITY
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void blk_flush_integrity(void);
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#else
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static inline void blk_flush_integrity(void)
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{
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}
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#endif
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void blk_timeout_work(struct work_struct *work);
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unsigned long blk_rq_timeout(unsigned long timeout);
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void blk_add_timer(struct request *req);
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void blk_delete_timer(struct request *);
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bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
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struct bio *bio);
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bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
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struct bio *bio);
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bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
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struct bio *bio);
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bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
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unsigned int *request_count,
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struct request **same_queue_rq);
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unsigned int blk_plug_queued_count(struct request_queue *q);
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void blk_account_io_start(struct request *req, bool new_io);
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void blk_account_io_completion(struct request *req, unsigned int bytes);
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void blk_account_io_done(struct request *req);
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/*
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* Internal atomic flags for request handling
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*/
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enum rq_atomic_flags {
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REQ_ATOM_COMPLETE = 0,
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REQ_ATOM_STARTED,
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REQ_ATOM_POLL_SLEPT,
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};
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/*
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* EH timer and IO completion will both attempt to 'grab' the request, make
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* sure that only one of them succeeds
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*/
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static inline int blk_mark_rq_complete(struct request *rq)
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{
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return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
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}
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static inline void blk_clear_rq_complete(struct request *rq)
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{
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clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
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}
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/*
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* Internal elevator interface
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*/
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#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
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void blk_insert_flush(struct request *rq);
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static inline struct request *__elv_next_request(struct request_queue *q)
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{
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struct request *rq;
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struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
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WARN_ON_ONCE(q->mq_ops);
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while (1) {
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if (!list_empty(&q->queue_head)) {
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rq = list_entry_rq(q->queue_head.next);
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return rq;
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}
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/*
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* Flush request is running and flush request isn't queueable
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* in the drive, we can hold the queue till flush request is
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* finished. Even we don't do this, driver can't dispatch next
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* requests and will requeue them. And this can improve
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* throughput too. For example, we have request flush1, write1,
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* flush 2. flush1 is dispatched, then queue is hold, write1
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* isn't inserted to queue. After flush1 is finished, flush2
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* will be dispatched. Since disk cache is already clean,
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* flush2 will be finished very soon, so looks like flush2 is
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* folded to flush1.
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* Since the queue is hold, a flag is set to indicate the queue
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* should be restarted later. Please see flush_end_io() for
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* details.
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*/
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if (fq->flush_pending_idx != fq->flush_running_idx &&
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!queue_flush_queueable(q)) {
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fq->flush_queue_delayed = 1;
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return NULL;
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}
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if (unlikely(blk_queue_bypass(q)) ||
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!q->elevator->type->ops.sq.elevator_dispatch_fn(q, 0))
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return NULL;
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}
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}
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static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
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{
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struct elevator_queue *e = q->elevator;
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if (e->type->ops.sq.elevator_activate_req_fn)
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e->type->ops.sq.elevator_activate_req_fn(q, rq);
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}
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static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
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{
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struct elevator_queue *e = q->elevator;
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if (e->type->ops.sq.elevator_deactivate_req_fn)
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e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
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}
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#ifdef CONFIG_FAIL_IO_TIMEOUT
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int blk_should_fake_timeout(struct request_queue *);
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ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
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ssize_t part_timeout_store(struct device *, struct device_attribute *,
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const char *, size_t);
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#else
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static inline int blk_should_fake_timeout(struct request_queue *q)
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{
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return 0;
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}
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#endif
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int ll_back_merge_fn(struct request_queue *q, struct request *req,
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struct bio *bio);
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int ll_front_merge_fn(struct request_queue *q, struct request *req,
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struct bio *bio);
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struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
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struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
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int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
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struct request *next);
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void blk_recalc_rq_segments(struct request *rq);
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void blk_rq_set_mixed_merge(struct request *rq);
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bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
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enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
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void blk_queue_congestion_threshold(struct request_queue *q);
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int blk_dev_init(void);
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/*
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* Return the threshold (number of used requests) at which the queue is
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* considered to be congested. It include a little hysteresis to keep the
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* context switch rate down.
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*/
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static inline int queue_congestion_on_threshold(struct request_queue *q)
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{
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return q->nr_congestion_on;
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}
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/*
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* The threshold at which a queue is considered to be uncongested
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*/
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static inline int queue_congestion_off_threshold(struct request_queue *q)
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{
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return q->nr_congestion_off;
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}
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extern int blk_update_nr_requests(struct request_queue *, unsigned int);
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/*
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* Contribute to IO statistics IFF:
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*
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* a) it's attached to a gendisk, and
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* b) the queue had IO stats enabled when this request was started, and
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* c) it's a file system request
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*/
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static inline int blk_do_io_stat(struct request *rq)
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{
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return rq->rq_disk &&
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(rq->rq_flags & RQF_IO_STAT) &&
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!blk_rq_is_passthrough(rq);
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}
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static inline void req_set_nomerge(struct request_queue *q, struct request *req)
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{
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req->cmd_flags |= REQ_NOMERGE;
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if (req == q->last_merge)
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q->last_merge = NULL;
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}
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/*
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* Internal io_context interface
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*/
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void get_io_context(struct io_context *ioc);
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struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
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struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
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gfp_t gfp_mask);
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void ioc_clear_queue(struct request_queue *q);
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int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
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/**
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* rq_ioc - determine io_context for request allocation
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* @bio: request being allocated is for this bio (can be %NULL)
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*
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* Determine io_context to use for request allocation for @bio. May return
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* %NULL if %current->io_context doesn't exist.
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*/
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static inline struct io_context *rq_ioc(struct bio *bio)
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{
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#ifdef CONFIG_BLK_CGROUP
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if (bio && bio->bi_ioc)
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return bio->bi_ioc;
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#endif
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return current->io_context;
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}
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/**
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* create_io_context - try to create task->io_context
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* @gfp_mask: allocation mask
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* @node: allocation node
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*
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* If %current->io_context is %NULL, allocate a new io_context and install
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* it. Returns the current %current->io_context which may be %NULL if
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* allocation failed.
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*
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* Note that this function can't be called with IRQ disabled because
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* task_lock which protects %current->io_context is IRQ-unsafe.
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*/
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static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
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{
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WARN_ON_ONCE(irqs_disabled());
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if (unlikely(!current->io_context))
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create_task_io_context(current, gfp_mask, node);
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return current->io_context;
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}
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/*
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* Internal throttling interface
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*/
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#ifdef CONFIG_BLK_DEV_THROTTLING
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extern void blk_throtl_drain(struct request_queue *q);
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extern int blk_throtl_init(struct request_queue *q);
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extern void blk_throtl_exit(struct request_queue *q);
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extern void blk_throtl_register_queue(struct request_queue *q);
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#else /* CONFIG_BLK_DEV_THROTTLING */
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static inline void blk_throtl_drain(struct request_queue *q) { }
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static inline int blk_throtl_init(struct request_queue *q) { return 0; }
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static inline void blk_throtl_exit(struct request_queue *q) { }
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static inline void blk_throtl_register_queue(struct request_queue *q) { }
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#endif /* CONFIG_BLK_DEV_THROTTLING */
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#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
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extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
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extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
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const char *page, size_t count);
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extern void blk_throtl_bio_endio(struct bio *bio);
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extern void blk_throtl_stat_add(struct request *rq, u64 time);
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#else
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static inline void blk_throtl_bio_endio(struct bio *bio) { }
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static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
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#endif
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#ifdef CONFIG_BOUNCE
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extern int init_emergency_isa_pool(void);
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extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
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#else
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static inline int init_emergency_isa_pool(void)
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{
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return 0;
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}
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static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
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{
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}
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#endif /* CONFIG_BOUNCE */
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#endif /* BLK_INTERNAL_H */
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