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block/elevator.c
24.5 KB
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/* |
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* Block device elevator/IO-scheduler. * * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE * |
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* 30042000 Jens Axboe <axboe@kernel.dk> : |
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* * Split the elevator a bit so that it is possible to choose a different * one or even write a new "plug in". There are three pieces: * - elevator_fn, inserts a new request in the queue list * - elevator_merge_fn, decides whether a new buffer can be merged with * an existing request * - elevator_dequeue_fn, called when a request is taken off the active list * * 20082000 Dave Jones <davej@suse.de> : * Removed tests for max-bomb-segments, which was breaking elvtune * when run without -bN * * Jens: * - Rework again to work with bio instead of buffer_heads * - loose bi_dev comparisons, partition handling is right now * - completely modularize elevator setup and teardown * */ #include <linux/kernel.h> #include <linux/fs.h> #include <linux/blkdev.h> #include <linux/elevator.h> #include <linux/bio.h> |
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#include <linux/module.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/compiler.h> |
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#include <linux/blktrace_api.h> |
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#include <linux/hash.h> |
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#include <linux/uaccess.h> |
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|
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#include <trace/events/block.h> |
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#include "blk.h" |
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static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); /* |
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* Merge hash stuff. */ static const int elv_hash_shift = 6; #define ELV_HASH_BLOCK(sec) ((sec) >> 3) |
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#define ELV_HASH_FN(sec) \ (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift)) |
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#define ELV_HASH_ENTRIES (1 << elv_hash_shift) |
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#define rq_hash_key(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
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/* |
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* Query io scheduler to see if the current process issuing bio may be * merged with rq. */ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio) { |
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struct request_queue *q = rq->q; |
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struct elevator_queue *e = q->elevator; |
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|
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if (e->type->ops.elevator_allow_merge_fn) return e->type->ops.elevator_allow_merge_fn(q, rq, bio); |
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return 1; } /* |
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* can we safely merge with this request? */ |
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int elv_rq_merge_ok(struct request *rq, struct bio *bio) |
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{ if (!rq_mergeable(rq)) return 0; /* |
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* Don't merge file system requests and discard requests */ |
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if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD)) |
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return 0; /* |
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* Don't merge discard requests and secure discard requests */ if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE)) return 0; /* |
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* different data direction or already started, don't merge */ if (bio_data_dir(bio) != rq_data_dir(rq)) return 0; /* |
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* must be same device and not a special request |
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*/ |
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if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special) |
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return 0; |
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/* * only merge integrity protected bio into ditto rq */ if (bio_integrity(bio) != blk_integrity_rq(rq)) return 0; |
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if (!elv_iosched_allow_merge(rq, bio)) return 0; |
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|
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return 1; |
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} EXPORT_SYMBOL(elv_rq_merge_ok); |
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int elv_try_merge(struct request *__rq, struct bio *bio) |
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{ int ret = ELEVATOR_NO_MERGE; /* * we can merge and sequence is ok, check if it's possible */ if (elv_rq_merge_ok(__rq, bio)) { |
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if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector) |
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ret = ELEVATOR_BACK_MERGE; |
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else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector) |
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ret = ELEVATOR_FRONT_MERGE; } return ret; } |
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|
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static struct elevator_type *elevator_find(const char *name) { |
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struct elevator_type *e; |
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|
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list_for_each_entry(e, &elv_list, list) { |
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if (!strcmp(e->elevator_name, name)) return e; |
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} |
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|
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return NULL; |
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} static void elevator_put(struct elevator_type *e) { module_put(e->elevator_owner); } static struct elevator_type *elevator_get(const char *name) { |
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struct elevator_type *e; |
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|
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spin_lock(&elv_list_lock); |
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e = elevator_find(name); |
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if (!e) { |
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spin_unlock(&elv_list_lock); |
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request_module("%s-iosched", name); |
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spin_lock(&elv_list_lock); e = elevator_find(name); } |
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if (e && !try_module_get(e->elevator_owner)) e = NULL; |
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spin_unlock(&elv_list_lock); |
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return e; } |
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static int elevator_init_queue(struct request_queue *q, struct elevator_queue *eq) |
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{ |
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eq->elevator_data = eq->type->ops.elevator_init_fn(q); |
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if (eq->elevator_data) return 0; return -ENOMEM; |
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} |
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static char chosen_elevator[ELV_NAME_MAX]; |
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|
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static int __init elevator_setup(char *str) |
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{ |
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/* * Be backwards-compatible with previous kernels, so users * won't get the wrong elevator. */ |
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strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); |
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return 1; |
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} __setup("elevator=", elevator_setup); |
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static struct kobj_type elv_ktype; |
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static struct elevator_queue *elevator_alloc(struct request_queue *q, |
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struct elevator_type *e) |
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{ |
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struct elevator_queue *eq; |
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int i; |
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eq = kmalloc_node(sizeof(*eq), GFP_KERNEL | __GFP_ZERO, q->node); |
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if (unlikely(!eq)) goto err; |
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eq->type = e; |
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kobject_init(&eq->kobj, &elv_ktype); |
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mutex_init(&eq->sysfs_lock); |
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eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES, GFP_KERNEL, q->node); |
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if (!eq->hash) goto err; for (i = 0; i < ELV_HASH_ENTRIES; i++) INIT_HLIST_HEAD(&eq->hash[i]); |
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return eq; |
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err: kfree(eq); elevator_put(e); return NULL; |
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} static void elevator_release(struct kobject *kobj) { |
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struct elevator_queue *e; |
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|
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e = container_of(kobj, struct elevator_queue, kobj); |
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elevator_put(e->type); |
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kfree(e->hash); |
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kfree(e); } |
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int elevator_init(struct request_queue *q, char *name) |
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{ struct elevator_type *e = NULL; struct elevator_queue *eq; |
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int err; |
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|
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if (unlikely(q->elevator)) return 0; |
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INIT_LIST_HEAD(&q->queue_head); q->last_merge = NULL; q->end_sector = 0; q->boundary_rq = NULL; |
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|
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if (name) { e = elevator_get(name); if (!e) return -EINVAL; } |
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|
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if (!e && *chosen_elevator) { e = elevator_get(chosen_elevator); if (!e) printk(KERN_ERR "I/O scheduler %s not found ", chosen_elevator); } |
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|
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if (!e) { e = elevator_get(CONFIG_DEFAULT_IOSCHED); if (!e) { printk(KERN_ERR "Default I/O scheduler not found. " \ "Using noop. "); e = elevator_get("noop"); } |
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} |
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eq = elevator_alloc(q, e); |
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if (!eq) |
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return -ENOMEM; |
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|
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err = elevator_init_queue(q, eq); if (err) { |
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kobject_put(&eq->kobj); |
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return err; |
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} |
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|
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q->elevator = eq; |
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return 0; |
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} |
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EXPORT_SYMBOL(elevator_init); |
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void elevator_exit(struct elevator_queue *e) |
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{ |
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mutex_lock(&e->sysfs_lock); |
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if (e->type->ops.elevator_exit_fn) e->type->ops.elevator_exit_fn(e); |
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mutex_unlock(&e->sysfs_lock); |
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|
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kobject_put(&e->kobj); |
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} |
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EXPORT_SYMBOL(elevator_exit); |
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static inline void __elv_rqhash_del(struct request *rq) { hlist_del_init(&rq->hash); } |
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static void elv_rqhash_del(struct request_queue *q, struct request *rq) |
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{ if (ELV_ON_HASH(rq)) __elv_rqhash_del(rq); } |
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static void elv_rqhash_add(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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BUG_ON(ELV_ON_HASH(rq)); hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]); } |
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static void elv_rqhash_reposition(struct request_queue *q, struct request *rq) |
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{ __elv_rqhash_del(rq); elv_rqhash_add(q, rq); } |
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static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset) |
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{ |
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struct elevator_queue *e = q->elevator; |
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struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)]; struct hlist_node *entry, *next; struct request *rq; hlist_for_each_entry_safe(rq, entry, next, hash_list, hash) { BUG_ON(!ELV_ON_HASH(rq)); if (unlikely(!rq_mergeable(rq))) { __elv_rqhash_del(rq); continue; } if (rq_hash_key(rq) == offset) return rq; } return NULL; } |
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/* |
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* RB-tree support functions for inserting/lookup/removal of requests * in a sorted RB tree. */ |
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void elv_rb_add(struct rb_root *root, struct request *rq) |
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{ struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; struct request *__rq; while (*p) { parent = *p; __rq = rb_entry(parent, struct request, rb_node); |
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if (blk_rq_pos(rq) < blk_rq_pos(__rq)) |
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p = &(*p)->rb_left; |
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else if (blk_rq_pos(rq) >= blk_rq_pos(__rq)) |
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p = &(*p)->rb_right; |
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} rb_link_node(&rq->rb_node, parent, p); rb_insert_color(&rq->rb_node, root); |
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} |
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EXPORT_SYMBOL(elv_rb_add); void elv_rb_del(struct rb_root *root, struct request *rq) { BUG_ON(RB_EMPTY_NODE(&rq->rb_node)); rb_erase(&rq->rb_node, root); RB_CLEAR_NODE(&rq->rb_node); } |
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EXPORT_SYMBOL(elv_rb_del); struct request *elv_rb_find(struct rb_root *root, sector_t sector) { struct rb_node *n = root->rb_node; struct request *rq; while (n) { rq = rb_entry(n, struct request, rb_node); |
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if (sector < blk_rq_pos(rq)) |
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n = n->rb_left; |
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else if (sector > blk_rq_pos(rq)) |
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n = n->rb_right; else return rq; } return NULL; } |
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EXPORT_SYMBOL(elv_rb_find); /* |
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* Insert rq into dispatch queue of q. Queue lock must be held on |
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* entry. rq is sort instead into the dispatch queue. To be used by |
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* specific elevators. |
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*/ |
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void elv_dispatch_sort(struct request_queue *q, struct request *rq) |
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{ sector_t boundary; |
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struct list_head *entry; |
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int stop_flags; |
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|
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if (q->last_merge == rq) q->last_merge = NULL; |
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elv_rqhash_del(q, rq); |
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q->nr_sorted--; |
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|
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boundary = q->end_sector; |
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stop_flags = REQ_SOFTBARRIER | REQ_STARTED; |
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list_for_each_prev(entry, &q->queue_head) { struct request *pos = list_entry_rq(entry); |
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if ((rq->cmd_flags & REQ_DISCARD) != (pos->cmd_flags & REQ_DISCARD)) |
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break; |
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if (rq_data_dir(rq) != rq_data_dir(pos)) break; |
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if (pos->cmd_flags & stop_flags) |
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break; |
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if (blk_rq_pos(rq) >= boundary) { if (blk_rq_pos(pos) < boundary) |
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continue; } else { |
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if (blk_rq_pos(pos) >= boundary) |
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break; } |
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if (blk_rq_pos(rq) >= blk_rq_pos(pos)) |
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break; } list_add(&rq->queuelist, entry); } |
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EXPORT_SYMBOL(elv_dispatch_sort); |
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/* |
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* Insert rq into dispatch queue of q. Queue lock must be held on * entry. rq is added to the back of the dispatch queue. To be used by * specific elevators. |
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*/ void elv_dispatch_add_tail(struct request_queue *q, struct request *rq) { if (q->last_merge == rq) q->last_merge = NULL; elv_rqhash_del(q, rq); q->nr_sorted--; q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; list_add_tail(&rq->queuelist, &q->queue_head); } |
2e662b65f [PATCH] elevator:... |
433 |
EXPORT_SYMBOL(elv_dispatch_add_tail); |
165125e1e [BLOCK] Get rid o... |
434 |
int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
435 |
{ |
b374d18a4 block: get rid of... |
436 |
struct elevator_queue *e = q->elevator; |
9817064b6 [PATCH] elevator:... |
437 |
struct request *__rq; |
06b86245c [PATCH] 03/05 mov... |
438 |
int ret; |
9817064b6 [PATCH] elevator:... |
439 |
/* |
488991e28 block: Added in s... |
440 441 442 443 444 445 446 447 448 |
* Levels of merges: * nomerges: No merges at all attempted * noxmerges: Only simple one-hit cache try * merges: All merge tries attempted */ if (blk_queue_nomerges(q)) return ELEVATOR_NO_MERGE; /* |
9817064b6 [PATCH] elevator:... |
449 450 |
* First try one-hit cache. */ |
06b86245c [PATCH] 03/05 mov... |
451 452 453 454 455 456 457 |
if (q->last_merge) { ret = elv_try_merge(q->last_merge, bio); if (ret != ELEVATOR_NO_MERGE) { *req = q->last_merge; return ret; } } |
1da177e4c Linux-2.6.12-rc2 |
458 |
|
488991e28 block: Added in s... |
459 |
if (blk_queue_noxmerges(q)) |
ac9fafa12 block: Skip I/O m... |
460 |
return ELEVATOR_NO_MERGE; |
9817064b6 [PATCH] elevator:... |
461 462 463 464 465 466 467 468 |
/* * See if our hash lookup can find a potential backmerge. */ __rq = elv_rqhash_find(q, bio->bi_sector); if (__rq && elv_rq_merge_ok(__rq, bio)) { *req = __rq; return ELEVATOR_BACK_MERGE; } |
22f746e23 block: remove ele... |
469 470 |
if (e->type->ops.elevator_merge_fn) return e->type->ops.elevator_merge_fn(q, req, bio); |
1da177e4c Linux-2.6.12-rc2 |
471 472 473 |
return ELEVATOR_NO_MERGE; } |
5e84ea3a9 block: attempt to... |
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 |
/* * Attempt to do an insertion back merge. Only check for the case where * we can append 'rq' to an existing request, so we can throw 'rq' away * afterwards. * * Returns true if we merged, false otherwise */ static bool elv_attempt_insert_merge(struct request_queue *q, struct request *rq) { struct request *__rq; if (blk_queue_nomerges(q)) return false; /* * First try one-hit cache. */ if (q->last_merge && blk_attempt_req_merge(q, q->last_merge, rq)) return true; if (blk_queue_noxmerges(q)) return false; /* * See if our hash lookup can find a potential backmerge. */ |
5d381efb3 Revert "block: re... |
501 502 503 |
__rq = elv_rqhash_find(q, blk_rq_pos(rq)); if (__rq && blk_attempt_req_merge(q, __rq, rq)) return true; |
274193224 block: recursive ... |
504 |
|
5d381efb3 Revert "block: re... |
505 |
return false; |
5e84ea3a9 block: attempt to... |
506 |
} |
165125e1e [BLOCK] Get rid o... |
507 |
void elv_merged_request(struct request_queue *q, struct request *rq, int type) |
1da177e4c Linux-2.6.12-rc2 |
508 |
{ |
b374d18a4 block: get rid of... |
509 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
510 |
|
22f746e23 block: remove ele... |
511 512 |
if (e->type->ops.elevator_merged_fn) e->type->ops.elevator_merged_fn(q, rq, type); |
06b86245c [PATCH] 03/05 mov... |
513 |
|
2e662b65f [PATCH] elevator:... |
514 515 |
if (type == ELEVATOR_BACK_MERGE) elv_rqhash_reposition(q, rq); |
9817064b6 [PATCH] elevator:... |
516 |
|
06b86245c [PATCH] 03/05 mov... |
517 |
q->last_merge = rq; |
1da177e4c Linux-2.6.12-rc2 |
518 |
} |
165125e1e [BLOCK] Get rid o... |
519 |
void elv_merge_requests(struct request_queue *q, struct request *rq, |
1da177e4c Linux-2.6.12-rc2 |
520 521 |
struct request *next) { |
b374d18a4 block: get rid of... |
522 |
struct elevator_queue *e = q->elevator; |
5e84ea3a9 block: attempt to... |
523 |
const int next_sorted = next->cmd_flags & REQ_SORTED; |
1da177e4c Linux-2.6.12-rc2 |
524 |
|
22f746e23 block: remove ele... |
525 526 |
if (next_sorted && e->type->ops.elevator_merge_req_fn) e->type->ops.elevator_merge_req_fn(q, rq, next); |
06b86245c [PATCH] 03/05 mov... |
527 |
|
9817064b6 [PATCH] elevator:... |
528 |
elv_rqhash_reposition(q, rq); |
9817064b6 [PATCH] elevator:... |
529 |
|
5e84ea3a9 block: attempt to... |
530 531 532 533 |
if (next_sorted) { elv_rqhash_del(q, next); q->nr_sorted--; } |
06b86245c [PATCH] 03/05 mov... |
534 |
q->last_merge = rq; |
1da177e4c Linux-2.6.12-rc2 |
535 |
} |
812d40264 blkio: Add io_mer... |
536 537 538 539 |
void elv_bio_merged(struct request_queue *q, struct request *rq, struct bio *bio) { struct elevator_queue *e = q->elevator; |
22f746e23 block: remove ele... |
540 541 |
if (e->type->ops.elevator_bio_merged_fn) e->type->ops.elevator_bio_merged_fn(q, rq, bio); |
812d40264 blkio: Add io_mer... |
542 |
} |
165125e1e [BLOCK] Get rid o... |
543 |
void elv_requeue_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
544 |
{ |
1da177e4c Linux-2.6.12-rc2 |
545 546 547 548 |
/* * it already went through dequeue, we need to decrement the * in_flight count again */ |
8922e16cf [PATCH] 01/05 Imp... |
549 |
if (blk_account_rq(rq)) { |
0a7ae2ff0 block: change the... |
550 |
q->in_flight[rq_is_sync(rq)]--; |
33659ebba block: remove wra... |
551 |
if (rq->cmd_flags & REQ_SORTED) |
cad975164 elevator: abstrac... |
552 |
elv_deactivate_rq(q, rq); |
8922e16cf [PATCH] 01/05 Imp... |
553 |
} |
1da177e4c Linux-2.6.12-rc2 |
554 |
|
4aff5e233 [PATCH] Split str... |
555 |
rq->cmd_flags &= ~REQ_STARTED; |
1da177e4c Linux-2.6.12-rc2 |
556 |
|
b710a4805 block: get rid of... |
557 |
__elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE); |
1da177e4c Linux-2.6.12-rc2 |
558 |
} |
26308eab6 block: fix incons... |
559 |
void elv_drain_elevator(struct request_queue *q) |
15853af9f [BLOCK] Implement... |
560 561 |
{ static int printed; |
e3c78ca52 block: reorganize... |
562 563 |
lockdep_assert_held(q->queue_lock); |
22f746e23 block: remove ele... |
564 |
while (q->elevator->type->ops.elevator_dispatch_fn(q, 1)) |
15853af9f [BLOCK] Implement... |
565 |
; |
e3c78ca52 block: reorganize... |
566 |
if (q->nr_sorted && printed++ < 10) { |
15853af9f [BLOCK] Implement... |
567 568 569 |
printk(KERN_ERR "%s: forced dispatching is broken " "(nr_sorted=%u), please report this ", |
22f746e23 block: remove ele... |
570 |
q->elevator->type->elevator_name, q->nr_sorted); |
15853af9f [BLOCK] Implement... |
571 572 |
} } |
f600abe2d block: fix bad sp... |
573 |
void elv_quiesce_start(struct request_queue *q) |
6c7e8cee6 block: elevator q... |
574 |
{ |
cd43e26f0 block: Expose sta... |
575 576 |
if (!q->elevator) return; |
e3c78ca52 block: reorganize... |
577 |
spin_lock_irq(q->queue_lock); |
6c7e8cee6 block: elevator q... |
578 |
queue_flag_set(QUEUE_FLAG_ELVSWITCH, q); |
e3c78ca52 block: reorganize... |
579 |
spin_unlock_irq(q->queue_lock); |
6c7e8cee6 block: elevator q... |
580 |
|
c9a929dde block: fix reques... |
581 |
blk_drain_queue(q, false); |
6c7e8cee6 block: elevator q... |
582 |
} |
f600abe2d block: fix bad sp... |
583 |
void elv_quiesce_end(struct request_queue *q) |
6c7e8cee6 block: elevator q... |
584 |
{ |
e3c78ca52 block: reorganize... |
585 |
spin_lock_irq(q->queue_lock); |
6c7e8cee6 block: elevator q... |
586 |
queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q); |
e3c78ca52 block: reorganize... |
587 |
spin_unlock_irq(q->queue_lock); |
6c7e8cee6 block: elevator q... |
588 |
} |
b710a4805 block: get rid of... |
589 |
void __elv_add_request(struct request_queue *q, struct request *rq, int where) |
1da177e4c Linux-2.6.12-rc2 |
590 |
{ |
5f3ea37c7 blktrace: port to... |
591 |
trace_block_rq_insert(q, rq); |
2056a782f [PATCH] Block que... |
592 |
|
1da177e4c Linux-2.6.12-rc2 |
593 |
rq->q = q; |
b710a4805 block: get rid of... |
594 595 596 597 598 599 600 601 |
if (rq->cmd_flags & REQ_SOFTBARRIER) { /* barriers are scheduling boundary, update end_sector */ if (rq->cmd_type == REQ_TYPE_FS || (rq->cmd_flags & REQ_DISCARD)) { q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; } } else if (!(rq->cmd_flags & REQ_ELVPRIV) && |
3aa72873f elevator: check f... |
602 603 |
(where == ELEVATOR_INSERT_SORT || where == ELEVATOR_INSERT_SORT_MERGE)) |
b710a4805 block: get rid of... |
604 |
where = ELEVATOR_INSERT_BACK; |
8922e16cf [PATCH] 01/05 Imp... |
605 |
switch (where) { |
28e7d1845 block: drop barri... |
606 |
case ELEVATOR_INSERT_REQUEUE: |
8922e16cf [PATCH] 01/05 Imp... |
607 |
case ELEVATOR_INSERT_FRONT: |
4aff5e233 [PATCH] Split str... |
608 |
rq->cmd_flags |= REQ_SOFTBARRIER; |
8922e16cf [PATCH] 01/05 Imp... |
609 610 611 612 |
list_add(&rq->queuelist, &q->queue_head); break; case ELEVATOR_INSERT_BACK: |
4aff5e233 [PATCH] Split str... |
613 |
rq->cmd_flags |= REQ_SOFTBARRIER; |
15853af9f [BLOCK] Implement... |
614 |
elv_drain_elevator(q); |
8922e16cf [PATCH] 01/05 Imp... |
615 616 617 618 619 620 621 622 623 624 625 |
list_add_tail(&rq->queuelist, &q->queue_head); /* * We kick the queue here for the following reasons. * - The elevator might have returned NULL previously * to delay requests and returned them now. As the * queue wasn't empty before this request, ll_rw_blk * won't run the queue on return, resulting in hang. * - Usually, back inserted requests won't be merged * with anything. There's no point in delaying queue * processing. */ |
24ecfbe27 block: add blk_ru... |
626 |
__blk_run_queue(q); |
8922e16cf [PATCH] 01/05 Imp... |
627 |
break; |
5e84ea3a9 block: attempt to... |
628 629 630 631 632 633 634 635 |
case ELEVATOR_INSERT_SORT_MERGE: /* * If we succeed in merging this request with one in the * queue already, we are done - rq has now been freed, * so no need to do anything further. */ if (elv_attempt_insert_merge(q, rq)) break; |
8922e16cf [PATCH] 01/05 Imp... |
636 |
case ELEVATOR_INSERT_SORT: |
33659ebba block: remove wra... |
637 638 |
BUG_ON(rq->cmd_type != REQ_TYPE_FS && !(rq->cmd_flags & REQ_DISCARD)); |
4aff5e233 [PATCH] Split str... |
639 |
rq->cmd_flags |= REQ_SORTED; |
15853af9f [BLOCK] Implement... |
640 |
q->nr_sorted++; |
9817064b6 [PATCH] elevator:... |
641 642 643 644 645 |
if (rq_mergeable(rq)) { elv_rqhash_add(q, rq); if (!q->last_merge) q->last_merge = rq; } |
ca23509fb [PATCH] blk: fix ... |
646 647 648 649 650 |
/* * Some ioscheds (cfq) run q->request_fn directly, so * rq cannot be accessed after calling * elevator_add_req_fn. */ |
22f746e23 block: remove ele... |
651 |
q->elevator->type->ops.elevator_add_req_fn(q, rq); |
8922e16cf [PATCH] 01/05 Imp... |
652 |
break; |
ae1b15396 block: reimplemen... |
653 654 655 656 |
case ELEVATOR_INSERT_FLUSH: rq->cmd_flags |= REQ_SOFTBARRIER; blk_insert_flush(rq); break; |
8922e16cf [PATCH] 01/05 Imp... |
657 658 659 |
default: printk(KERN_ERR "%s: bad insertion point %d ", |
24c03d47d block: remove rem... |
660 |
__func__, where); |
8922e16cf [PATCH] 01/05 Imp... |
661 662 |
BUG(); } |
1da177e4c Linux-2.6.12-rc2 |
663 |
} |
2e662b65f [PATCH] elevator:... |
664 |
EXPORT_SYMBOL(__elv_add_request); |
7eaceacca block: remove per... |
665 |
void elv_add_request(struct request_queue *q, struct request *rq, int where) |
1da177e4c Linux-2.6.12-rc2 |
666 667 668 669 |
{ unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); |
7eaceacca block: remove per... |
670 |
__elv_add_request(q, rq, where); |
1da177e4c Linux-2.6.12-rc2 |
671 672 |
spin_unlock_irqrestore(q->queue_lock, flags); } |
2e662b65f [PATCH] elevator:... |
673 |
EXPORT_SYMBOL(elv_add_request); |
165125e1e [BLOCK] Get rid o... |
674 |
struct request *elv_latter_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
675 |
{ |
b374d18a4 block: get rid of... |
676 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
677 |
|
22f746e23 block: remove ele... |
678 679 |
if (e->type->ops.elevator_latter_req_fn) return e->type->ops.elevator_latter_req_fn(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
680 681 |
return NULL; } |
165125e1e [BLOCK] Get rid o... |
682 |
struct request *elv_former_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
683 |
{ |
b374d18a4 block: get rid of... |
684 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
685 |
|
22f746e23 block: remove ele... |
686 687 |
if (e->type->ops.elevator_former_req_fn) return e->type->ops.elevator_former_req_fn(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
688 689 |
return NULL; } |
165125e1e [BLOCK] Get rid o... |
690 |
int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
691 |
{ |
b374d18a4 block: get rid of... |
692 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
693 |
|
22f746e23 block: remove ele... |
694 695 |
if (e->type->ops.elevator_set_req_fn) return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask); |
1da177e4c Linux-2.6.12-rc2 |
696 697 |
return 0; } |
165125e1e [BLOCK] Get rid o... |
698 |
void elv_put_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
699 |
{ |
b374d18a4 block: get rid of... |
700 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
701 |
|
22f746e23 block: remove ele... |
702 703 |
if (e->type->ops.elevator_put_req_fn) e->type->ops.elevator_put_req_fn(rq); |
1da177e4c Linux-2.6.12-rc2 |
704 |
} |
165125e1e [BLOCK] Get rid o... |
705 |
int elv_may_queue(struct request_queue *q, int rw) |
1da177e4c Linux-2.6.12-rc2 |
706 |
{ |
b374d18a4 block: get rid of... |
707 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
708 |
|
22f746e23 block: remove ele... |
709 710 |
if (e->type->ops.elevator_may_queue_fn) return e->type->ops.elevator_may_queue_fn(q, rw); |
1da177e4c Linux-2.6.12-rc2 |
711 712 713 |
return ELV_MQUEUE_MAY; } |
11914a53d block: Add interf... |
714 715 716 |
void elv_abort_queue(struct request_queue *q) { struct request *rq; |
ae1b15396 block: reimplemen... |
717 |
blk_abort_flushes(q); |
11914a53d block: Add interf... |
718 719 720 |
while (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); rq->cmd_flags |= REQ_QUIET; |
5f3ea37c7 blktrace: port to... |
721 |
trace_block_rq_abort(q, rq); |
53c663ce0 block: fix a poss... |
722 723 724 725 726 |
/* * Mark this request as started so we don't trigger * any debug logic in the end I/O path. */ blk_start_request(rq); |
40cbbb781 block: implement ... |
727 |
__blk_end_request_all(rq, -EIO); |
11914a53d block: Add interf... |
728 729 730 |
} } EXPORT_SYMBOL(elv_abort_queue); |
165125e1e [BLOCK] Get rid o... |
731 |
void elv_completed_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
732 |
{ |
b374d18a4 block: get rid of... |
733 |
struct elevator_queue *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
734 735 736 737 |
/* * request is released from the driver, io must be done */ |
8922e16cf [PATCH] 01/05 Imp... |
738 |
if (blk_account_rq(rq)) { |
0a7ae2ff0 block: change the... |
739 |
q->in_flight[rq_is_sync(rq)]--; |
33659ebba block: remove wra... |
740 |
if ((rq->cmd_flags & REQ_SORTED) && |
22f746e23 block: remove ele... |
741 742 |
e->type->ops.elevator_completed_req_fn) e->type->ops.elevator_completed_req_fn(q, rq); |
1bc691d35 [PATCH] fix queue... |
743 |
} |
1da177e4c Linux-2.6.12-rc2 |
744 |
} |
3d1ab40f4 [PATCH] elevator_... |
745 746 747 748 |
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr) static ssize_t elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page) |
1da177e4c Linux-2.6.12-rc2 |
749 |
{ |
3d1ab40f4 [PATCH] elevator_... |
750 |
struct elv_fs_entry *entry = to_elv(attr); |
b374d18a4 block: get rid of... |
751 |
struct elevator_queue *e; |
3d1ab40f4 [PATCH] elevator_... |
752 753 754 755 |
ssize_t error; if (!entry->show) return -EIO; |
b374d18a4 block: get rid of... |
756 |
e = container_of(kobj, struct elevator_queue, kobj); |
3d1ab40f4 [PATCH] elevator_... |
757 |
mutex_lock(&e->sysfs_lock); |
22f746e23 block: remove ele... |
758 |
error = e->type ? entry->show(e, page) : -ENOENT; |
3d1ab40f4 [PATCH] elevator_... |
759 760 761 |
mutex_unlock(&e->sysfs_lock); return error; } |
1da177e4c Linux-2.6.12-rc2 |
762 |
|
3d1ab40f4 [PATCH] elevator_... |
763 764 765 766 |
static ssize_t elv_attr_store(struct kobject *kobj, struct attribute *attr, const char *page, size_t length) { |
3d1ab40f4 [PATCH] elevator_... |
767 |
struct elv_fs_entry *entry = to_elv(attr); |
b374d18a4 block: get rid of... |
768 |
struct elevator_queue *e; |
3d1ab40f4 [PATCH] elevator_... |
769 |
ssize_t error; |
1da177e4c Linux-2.6.12-rc2 |
770 |
|
3d1ab40f4 [PATCH] elevator_... |
771 772 |
if (!entry->store) return -EIO; |
1da177e4c Linux-2.6.12-rc2 |
773 |
|
b374d18a4 block: get rid of... |
774 |
e = container_of(kobj, struct elevator_queue, kobj); |
3d1ab40f4 [PATCH] elevator_... |
775 |
mutex_lock(&e->sysfs_lock); |
22f746e23 block: remove ele... |
776 |
error = e->type ? entry->store(e, page, length) : -ENOENT; |
3d1ab40f4 [PATCH] elevator_... |
777 778 779 |
mutex_unlock(&e->sysfs_lock); return error; } |
52cf25d0a Driver core: Cons... |
780 |
static const struct sysfs_ops elv_sysfs_ops = { |
3d1ab40f4 [PATCH] elevator_... |
781 782 783 784 785 786 787 788 |
.show = elv_attr_show, .store = elv_attr_store, }; static struct kobj_type elv_ktype = { .sysfs_ops = &elv_sysfs_ops, .release = elevator_release, }; |
f8fc877d3 block: reorder el... |
789 |
int __elv_register_queue(struct request_queue *q, struct elevator_queue *e) |
3d1ab40f4 [PATCH] elevator_... |
790 |
{ |
3d1ab40f4 [PATCH] elevator_... |
791 |
int error; |
b2d6db587 Kobject: rename k... |
792 |
error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched"); |
3d1ab40f4 [PATCH] elevator_... |
793 |
if (!error) { |
22f746e23 block: remove ele... |
794 |
struct elv_fs_entry *attr = e->type->elevator_attrs; |
3d1ab40f4 [PATCH] elevator_... |
795 |
if (attr) { |
e572ec7e4 [PATCH] fix rmmod... |
796 797 |
while (attr->attr.name) { if (sysfs_create_file(&e->kobj, &attr->attr)) |
3d1ab40f4 [PATCH] elevator_... |
798 |
break; |
e572ec7e4 [PATCH] fix rmmod... |
799 |
attr++; |
3d1ab40f4 [PATCH] elevator_... |
800 801 802 |
} } kobject_uevent(&e->kobj, KOBJ_ADD); |
430c62fb2 elevator: fix oop... |
803 |
e->registered = 1; |
3d1ab40f4 [PATCH] elevator_... |
804 805 |
} return error; |
1da177e4c Linux-2.6.12-rc2 |
806 |
} |
f8fc877d3 block: reorder el... |
807 |
int elv_register_queue(struct request_queue *q) |
bc1c11697 [PATCH] elevator ... |
808 |
{ |
f8fc877d3 block: reorder el... |
809 |
return __elv_register_queue(q, q->elevator); |
bc1c11697 [PATCH] elevator ... |
810 |
} |
f8fc877d3 block: reorder el... |
811 |
EXPORT_SYMBOL(elv_register_queue); |
bc1c11697 [PATCH] elevator ... |
812 |
|
1da177e4c Linux-2.6.12-rc2 |
813 814 |
void elv_unregister_queue(struct request_queue *q) { |
f8fc877d3 block: reorder el... |
815 816 817 818 819 820 821 |
if (q) { struct elevator_queue *e = q->elevator; kobject_uevent(&e->kobj, KOBJ_REMOVE); kobject_del(&e->kobj); e->registered = 0; } |
1da177e4c Linux-2.6.12-rc2 |
822 |
} |
01effb0dc block: allow init... |
823 |
EXPORT_SYMBOL(elv_unregister_queue); |
1da177e4c Linux-2.6.12-rc2 |
824 |
|
3d3c2379f block, cfq: move ... |
825 |
int elv_register(struct elevator_type *e) |
1da177e4c Linux-2.6.12-rc2 |
826 |
{ |
1ffb96c58 make elv_register... |
827 |
char *def = ""; |
2a12dcd71 [PATCH] elevator:... |
828 |
|
3d3c2379f block, cfq: move ... |
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 |
/* create icq_cache if requested */ if (e->icq_size) { if (WARN_ON(e->icq_size < sizeof(struct io_cq)) || WARN_ON(e->icq_align < __alignof__(struct io_cq))) return -EINVAL; snprintf(e->icq_cache_name, sizeof(e->icq_cache_name), "%s_io_cq", e->elevator_name); e->icq_cache = kmem_cache_create(e->icq_cache_name, e->icq_size, e->icq_align, 0, NULL); if (!e->icq_cache) return -ENOMEM; } /* register, don't allow duplicate names */ |
2a12dcd71 [PATCH] elevator:... |
844 |
spin_lock(&elv_list_lock); |
3d3c2379f block, cfq: move ... |
845 846 847 848 849 850 |
if (elevator_find(e->elevator_name)) { spin_unlock(&elv_list_lock); if (e->icq_cache) kmem_cache_destroy(e->icq_cache); return -EBUSY; } |
1da177e4c Linux-2.6.12-rc2 |
851 |
list_add_tail(&e->list, &elv_list); |
2a12dcd71 [PATCH] elevator:... |
852 |
spin_unlock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
853 |
|
3d3c2379f block, cfq: move ... |
854 |
/* print pretty message */ |
5f0039764 [BLOCK] elevator:... |
855 856 857 |
if (!strcmp(e->elevator_name, chosen_elevator) || (!*chosen_elevator && !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) |
1ffb96c58 make elv_register... |
858 |
def = " (default)"; |
4eb166d98 block: make eleva... |
859 860 861 |
printk(KERN_INFO "io scheduler %s registered%s ", e->elevator_name, def); |
3d3c2379f block, cfq: move ... |
862 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
863 864 865 866 867 |
} EXPORT_SYMBOL_GPL(elv_register); void elv_unregister(struct elevator_type *e) { |
3d3c2379f block, cfq: move ... |
868 |
/* unregister */ |
2a12dcd71 [PATCH] elevator:... |
869 |
spin_lock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
870 |
list_del_init(&e->list); |
2a12dcd71 [PATCH] elevator:... |
871 |
spin_unlock(&elv_list_lock); |
3d3c2379f block, cfq: move ... |
872 873 874 875 876 877 878 879 880 881 |
/* * Destroy icq_cache if it exists. icq's are RCU managed. Make * sure all RCU operations are complete before proceeding. */ if (e->icq_cache) { rcu_barrier(); kmem_cache_destroy(e->icq_cache); e->icq_cache = NULL; } |
1da177e4c Linux-2.6.12-rc2 |
882 883 884 885 886 887 888 |
} EXPORT_SYMBOL_GPL(elv_unregister); /* * switch to new_e io scheduler. be careful not to introduce deadlocks - * we don't free the old io scheduler, before we have allocated what we * need for the new one. this way we have a chance of going back to the old |
cb98fc8bb [BLOCK] Reimpleme... |
889 |
* one, if the new one fails init for some reason. |
1da177e4c Linux-2.6.12-rc2 |
890 |
*/ |
165125e1e [BLOCK] Get rid o... |
891 |
static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) |
1da177e4c Linux-2.6.12-rc2 |
892 |
{ |
b374d18a4 block: get rid of... |
893 |
struct elevator_queue *old_elevator, *e; |
5dd531a03 block: add functi... |
894 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
895 |
|
f8fc877d3 block: reorder el... |
896 |
/* allocate new elevator */ |
b5deef901 [PATCH] Make sure... |
897 |
e = elevator_alloc(q, new_e); |
1da177e4c Linux-2.6.12-rc2 |
898 |
if (!e) |
5dd531a03 block: add functi... |
899 |
return -ENOMEM; |
1da177e4c Linux-2.6.12-rc2 |
900 |
|
f8fc877d3 block: reorder el... |
901 902 |
err = elevator_init_queue(q, e); if (err) { |
bc1c11697 [PATCH] elevator ... |
903 |
kobject_put(&e->kobj); |
f8fc877d3 block: reorder el... |
904 |
return err; |
bc1c11697 [PATCH] elevator ... |
905 |
} |
f8fc877d3 block: reorder el... |
906 |
/* turn on BYPASS and drain all requests w/ elevator private data */ |
f600abe2d block: fix bad sp... |
907 |
elv_quiesce_start(q); |
cb98fc8bb [BLOCK] Reimpleme... |
908 |
|
f8fc877d3 block: reorder el... |
909 910 911 912 |
/* unregister old queue, register new one and kill old elevator */ if (q->elevator->registered) { elv_unregister_queue(q); err = __elv_register_queue(q, e); |
430c62fb2 elevator: fix oop... |
913 914 915 |
if (err) goto fail_register; } |
1da177e4c Linux-2.6.12-rc2 |
916 |
|
7e5a87944 block, cfq: move ... |
917 |
/* done, clear io_cq's, switch elevators and turn off BYPASS */ |
f8fc877d3 block: reorder el... |
918 |
spin_lock_irq(q->queue_lock); |
7e5a87944 block, cfq: move ... |
919 |
ioc_clear_queue(q); |
f8fc877d3 block: reorder el... |
920 921 922 |
old_elevator = q->elevator; q->elevator = e; spin_unlock_irq(q->queue_lock); |
1da177e4c Linux-2.6.12-rc2 |
923 |
elevator_exit(old_elevator); |
f600abe2d block: fix bad sp... |
924 |
elv_quiesce_end(q); |
75ad23bc0 block: make queue... |
925 |
|
22f746e23 block: remove ele... |
926 |
blk_add_trace_msg(q, "elv switch: %s", e->type->elevator_name); |
4722dc52a Added in elevator... |
927 |
|
5dd531a03 block: add functi... |
928 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
929 930 931 932 933 934 935 |
fail_register: /* * switch failed, exit the new io scheduler and reattach the old * one again (along with re-adding the sysfs dir) */ elevator_exit(e); |
1da177e4c Linux-2.6.12-rc2 |
936 |
elv_register_queue(q); |
e3c78ca52 block: reorganize... |
937 |
elv_quiesce_end(q); |
75ad23bc0 block: make queue... |
938 |
|
5dd531a03 block: add functi... |
939 |
return err; |
1da177e4c Linux-2.6.12-rc2 |
940 |
} |
5dd531a03 block: add functi... |
941 942 943 944 |
/* * Switch this queue to the given IO scheduler. */ int elevator_change(struct request_queue *q, const char *name) |
1da177e4c Linux-2.6.12-rc2 |
945 946 947 |
{ char elevator_name[ELV_NAME_MAX]; struct elevator_type *e; |
cd43e26f0 block: Expose sta... |
948 |
if (!q->elevator) |
5dd531a03 block: add functi... |
949 |
return -ENXIO; |
cd43e26f0 block: Expose sta... |
950 |
|
ee2e992cc block: simplify s... |
951 |
strlcpy(elevator_name, name, sizeof(elevator_name)); |
8c2795985 elv_iosched_store... |
952 |
e = elevator_get(strstrip(elevator_name)); |
1da177e4c Linux-2.6.12-rc2 |
953 954 955 956 957 |
if (!e) { printk(KERN_ERR "elevator: type %s not found ", elevator_name); return -EINVAL; } |
22f746e23 block: remove ele... |
958 |
if (!strcmp(elevator_name, q->elevator->type->elevator_name)) { |
2ca7d93bb [PATCH] block cle... |
959 |
elevator_put(e); |
5dd531a03 block: add functi... |
960 |
return 0; |
2ca7d93bb [PATCH] block cle... |
961 |
} |
1da177e4c Linux-2.6.12-rc2 |
962 |
|
5dd531a03 block: add functi... |
963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 |
return elevator_switch(q, e); } EXPORT_SYMBOL(elevator_change); ssize_t elv_iosched_store(struct request_queue *q, const char *name, size_t count) { int ret; if (!q->elevator) return count; ret = elevator_change(q, name); if (!ret) return count; printk(KERN_ERR "elevator: switch to %s failed ", name); return ret; |
1da177e4c Linux-2.6.12-rc2 |
982 |
} |
165125e1e [BLOCK] Get rid o... |
983 |
ssize_t elv_iosched_show(struct request_queue *q, char *name) |
1da177e4c Linux-2.6.12-rc2 |
984 |
{ |
b374d18a4 block: get rid of... |
985 |
struct elevator_queue *e = q->elevator; |
cd43e26f0 block: Expose sta... |
986 |
struct elevator_type *elv; |
70cee26e0 Use list_for_each... |
987 |
struct elevator_type *__e; |
1da177e4c Linux-2.6.12-rc2 |
988 |
int len = 0; |
e36f724b4 block: Adjust elv... |
989 |
if (!q->elevator || !blk_queue_stackable(q)) |
cd43e26f0 block: Expose sta... |
990 991 |
return sprintf(name, "none "); |
22f746e23 block: remove ele... |
992 |
elv = e->type; |
cd43e26f0 block: Expose sta... |
993 |
|
2a12dcd71 [PATCH] elevator:... |
994 |
spin_lock(&elv_list_lock); |
70cee26e0 Use list_for_each... |
995 |
list_for_each_entry(__e, &elv_list, list) { |
1da177e4c Linux-2.6.12-rc2 |
996 997 998 999 1000 |
if (!strcmp(elv->elevator_name, __e->elevator_name)) len += sprintf(name+len, "[%s] ", elv->elevator_name); else len += sprintf(name+len, "%s ", __e->elevator_name); } |
2a12dcd71 [PATCH] elevator:... |
1001 |
spin_unlock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
1002 1003 1004 1005 1006 |
len += sprintf(len+name, " "); return len; } |
165125e1e [BLOCK] Get rid o... |
1007 1008 |
struct request *elv_rb_former_request(struct request_queue *q, struct request *rq) |
2e662b65f [PATCH] elevator:... |
1009 1010 1011 1012 1013 1014 1015 1016 |
{ struct rb_node *rbprev = rb_prev(&rq->rb_node); if (rbprev) return rb_entry_rq(rbprev); return NULL; } |
2e662b65f [PATCH] elevator:... |
1017 |
EXPORT_SYMBOL(elv_rb_former_request); |
165125e1e [BLOCK] Get rid o... |
1018 1019 |
struct request *elv_rb_latter_request(struct request_queue *q, struct request *rq) |
2e662b65f [PATCH] elevator:... |
1020 1021 1022 1023 1024 1025 1026 1027 |
{ struct rb_node *rbnext = rb_next(&rq->rb_node); if (rbnext) return rb_entry_rq(rbnext); return NULL; } |
2e662b65f [PATCH] elevator:... |
1028 |
EXPORT_SYMBOL(elv_rb_latter_request); |