Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Block device elevator/IO-scheduler. |
| 3 | * |
| 4 | * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE |
| 5 | * |
Jens Axboe | 0fe2347 | 2006-09-04 15:41:16 +0200 | [diff] [blame] | 6 | * 30042000 Jens Axboe <axboe@kernel.dk> : |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * |
| 8 | * Split the elevator a bit so that it is possible to choose a different |
| 9 | * one or even write a new "plug in". There are three pieces: |
| 10 | * - elevator_fn, inserts a new request in the queue list |
| 11 | * - elevator_merge_fn, decides whether a new buffer can be merged with |
| 12 | * an existing request |
| 13 | * - elevator_dequeue_fn, called when a request is taken off the active list |
| 14 | * |
| 15 | * 20082000 Dave Jones <davej@suse.de> : |
| 16 | * Removed tests for max-bomb-segments, which was breaking elvtune |
| 17 | * when run without -bN |
| 18 | * |
| 19 | * Jens: |
| 20 | * - Rework again to work with bio instead of buffer_heads |
| 21 | * - loose bi_dev comparisons, partition handling is right now |
| 22 | * - completely modularize elevator setup and teardown |
| 23 | * |
| 24 | */ |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/fs.h> |
| 27 | #include <linux/blkdev.h> |
| 28 | #include <linux/elevator.h> |
| 29 | #include <linux/bio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <linux/module.h> |
| 31 | #include <linux/slab.h> |
| 32 | #include <linux/init.h> |
| 33 | #include <linux/compiler.h> |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 34 | #include <linux/blktrace_api.h> |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 35 | #include <linux/hash.h> |
Jens Axboe | 0835da6 | 2008-08-26 09:15:47 +0200 | [diff] [blame] | 36 | #include <linux/uaccess.h> |
Lin Ming | c815881 | 2013-03-23 11:42:27 +0800 | [diff] [blame] | 37 | #include <linux/pm_runtime.h> |
Tejun Heo | eea8f41 | 2015-05-22 17:13:17 -0400 | [diff] [blame] | 38 | #include <linux/blk-cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
Li Zefan | 5578213 | 2009-06-09 13:43:05 +0800 | [diff] [blame] | 40 | #include <trace/events/block.h> |
| 41 | |
Jens Axboe | 242f9dc | 2008-09-14 05:55:09 -0700 | [diff] [blame] | 42 | #include "blk.h" |
| 43 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | static DEFINE_SPINLOCK(elv_list_lock); |
| 45 | static LIST_HEAD(elv_list); |
| 46 | |
| 47 | /* |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 48 | * Merge hash stuff. |
| 49 | */ |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 50 | #define rq_hash_key(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 51 | |
| 52 | /* |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 53 | * Query io scheduler to see if the current process issuing bio may be |
| 54 | * merged with rq. |
| 55 | */ |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 56 | static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio) |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 57 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 58 | struct request_queue *q = rq->q; |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 59 | struct elevator_queue *e = q->elevator; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 60 | |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 61 | if (e->type->ops.elevator_allow_bio_merge_fn) |
| 62 | return e->type->ops.elevator_allow_bio_merge_fn(q, rq, bio); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 63 | |
| 64 | return 1; |
| 65 | } |
| 66 | |
| 67 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | * can we safely merge with this request? |
| 69 | */ |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 70 | bool elv_bio_merge_ok(struct request *rq, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | { |
Tejun Heo | 050c8ea | 2012-02-08 09:19:38 +0100 | [diff] [blame] | 72 | if (!blk_rq_merge_ok(rq, bio)) |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 73 | return false; |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 74 | |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 75 | if (!elv_iosched_allow_bio_merge(rq, bio)) |
| 76 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 77 | |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 78 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | } |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 80 | EXPORT_SYMBOL(elv_bio_merge_ok); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | static struct elevator_type *elevator_find(const char *name) |
| 83 | { |
Vasily Tarasov | a22b169 | 2006-10-11 09:24:27 +0200 | [diff] [blame] | 84 | struct elevator_type *e; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Matthias Kaehlcke | 70cee26 | 2007-07-10 12:26:24 +0200 | [diff] [blame] | 86 | list_for_each_entry(e, &elv_list, list) { |
Vasily Tarasov | a22b169 | 2006-10-11 09:24:27 +0200 | [diff] [blame] | 87 | if (!strcmp(e->elevator_name, name)) |
| 88 | return e; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Vasily Tarasov | a22b169 | 2006-10-11 09:24:27 +0200 | [diff] [blame] | 91 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | } |
| 93 | |
| 94 | static void elevator_put(struct elevator_type *e) |
| 95 | { |
| 96 | module_put(e->elevator_owner); |
| 97 | } |
| 98 | |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 99 | static struct elevator_type *elevator_get(const char *name, bool try_loading) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | { |
Tejun Heo | 2824bc93 | 2005-10-20 10:56:41 +0200 | [diff] [blame] | 101 | struct elevator_type *e; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 103 | spin_lock(&elv_list_lock); |
Tejun Heo | 2824bc93 | 2005-10-20 10:56:41 +0200 | [diff] [blame] | 104 | |
| 105 | e = elevator_find(name); |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 106 | if (!e && try_loading) { |
Jens Axboe | e164094 | 2008-02-19 10:20:37 +0100 | [diff] [blame] | 107 | spin_unlock(&elv_list_lock); |
Kees Cook | 490b94b | 2011-05-05 18:02:12 -0600 | [diff] [blame] | 108 | request_module("%s-iosched", name); |
Jens Axboe | e164094 | 2008-02-19 10:20:37 +0100 | [diff] [blame] | 109 | spin_lock(&elv_list_lock); |
| 110 | e = elevator_find(name); |
| 111 | } |
| 112 | |
Tejun Heo | 2824bc93 | 2005-10-20 10:56:41 +0200 | [diff] [blame] | 113 | if (e && !try_module_get(e->elevator_owner)) |
| 114 | e = NULL; |
| 115 | |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 116 | spin_unlock(&elv_list_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | |
| 118 | return e; |
| 119 | } |
| 120 | |
Wang Sheng-Hui | 484fc25 | 2011-09-08 12:32:14 +0200 | [diff] [blame] | 121 | static char chosen_elevator[ELV_NAME_MAX]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
Nate Diller | 5f00397 | 2006-01-24 10:07:58 +0100 | [diff] [blame] | 123 | static int __init elevator_setup(char *str) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | { |
Chuck Ebbert | 752a3b7 | 2006-01-16 09:47:37 +0100 | [diff] [blame] | 125 | /* |
| 126 | * Be backwards-compatible with previous kernels, so users |
| 127 | * won't get the wrong elevator. |
| 128 | */ |
Jens Axboe | 492af63 | 2009-10-03 09:37:51 +0200 | [diff] [blame] | 129 | strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); |
OGAWA Hirofumi | 9b41046 | 2006-03-31 02:30:33 -0800 | [diff] [blame] | 130 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | } |
| 132 | |
| 133 | __setup("elevator=", elevator_setup); |
| 134 | |
Tejun Heo | bb813f4 | 2013-01-18 14:05:56 -0800 | [diff] [blame] | 135 | /* called during boot to load the elevator chosen by the elevator param */ |
| 136 | void __init load_default_elevator_module(void) |
| 137 | { |
| 138 | struct elevator_type *e; |
| 139 | |
| 140 | if (!chosen_elevator[0]) |
| 141 | return; |
| 142 | |
| 143 | spin_lock(&elv_list_lock); |
| 144 | e = elevator_find(chosen_elevator); |
| 145 | spin_unlock(&elv_list_lock); |
| 146 | |
| 147 | if (!e) |
| 148 | request_module("%s-iosched", chosen_elevator); |
| 149 | } |
| 150 | |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 151 | static struct kobj_type elv_ktype; |
| 152 | |
Jianpeng Ma | d50235b | 2013-07-03 13:25:24 +0200 | [diff] [blame] | 153 | struct elevator_queue *elevator_alloc(struct request_queue *q, |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 154 | struct elevator_type *e) |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 155 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 156 | struct elevator_queue *eq; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 157 | |
Joe Perches | c1b511e | 2013-08-29 15:21:42 -0700 | [diff] [blame] | 158 | eq = kzalloc_node(sizeof(*eq), GFP_KERNEL, q->node); |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 159 | if (unlikely(!eq)) |
Chao Yu | 8406a4d | 2015-04-23 10:47:44 -0600 | [diff] [blame] | 160 | return NULL; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 161 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 162 | eq->type = e; |
Greg Kroah-Hartman | f9cb074 | 2007-12-17 23:05:35 -0700 | [diff] [blame] | 163 | kobject_init(&eq->kobj, &elv_ktype); |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 164 | mutex_init(&eq->sysfs_lock); |
Sasha Levin | 242d98f | 2012-12-17 10:01:27 -0500 | [diff] [blame] | 165 | hash_init(eq->hash); |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 166 | |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 167 | return eq; |
| 168 | } |
Jianpeng Ma | d50235b | 2013-07-03 13:25:24 +0200 | [diff] [blame] | 169 | EXPORT_SYMBOL(elevator_alloc); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 170 | |
| 171 | static void elevator_release(struct kobject *kobj) |
| 172 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 173 | struct elevator_queue *e; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 174 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 175 | e = container_of(kobj, struct elevator_queue, kobj); |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 176 | elevator_put(e->type); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 177 | kfree(e); |
| 178 | } |
| 179 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 180 | int elevator_init(struct request_queue *q, char *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | { |
| 182 | struct elevator_type *e = NULL; |
Tejun Heo | f8fc877 | 2011-12-14 00:33:40 +0100 | [diff] [blame] | 183 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | |
Tomoki Sekiyama | eb1c160 | 2013-10-15 16:42:16 -0600 | [diff] [blame] | 185 | /* |
| 186 | * q->sysfs_lock must be held to provide mutual exclusion between |
| 187 | * elevator_switch() and here. |
| 188 | */ |
| 189 | lockdep_assert_held(&q->sysfs_lock); |
| 190 | |
Mike Snitzer | 1abec4f | 2010-05-25 13:15:15 -0400 | [diff] [blame] | 191 | if (unlikely(q->elevator)) |
| 192 | return 0; |
| 193 | |
Tejun Heo | cb98fc8 | 2005-10-28 08:29:39 +0200 | [diff] [blame] | 194 | INIT_LIST_HEAD(&q->queue_head); |
| 195 | q->last_merge = NULL; |
| 196 | q->end_sector = 0; |
| 197 | q->boundary_rq = NULL; |
Tejun Heo | cb98fc8 | 2005-10-28 08:29:39 +0200 | [diff] [blame] | 198 | |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 199 | if (name) { |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 200 | e = elevator_get(name, true); |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 201 | if (!e) |
| 202 | return -EINVAL; |
| 203 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 205 | /* |
| 206 | * Use the default elevator specified by config boot param or |
| 207 | * config option. Don't try to load modules as we could be running |
| 208 | * off async and request_module() isn't allowed from async. |
| 209 | */ |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 210 | if (!e && *chosen_elevator) { |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 211 | e = elevator_get(chosen_elevator, false); |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 212 | if (!e) |
| 213 | printk(KERN_ERR "I/O scheduler %s not found\n", |
| 214 | chosen_elevator); |
| 215 | } |
Nate Diller | 248d5ca | 2006-01-24 10:09:14 +0100 | [diff] [blame] | 216 | |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 217 | if (!e) { |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 218 | e = elevator_get(CONFIG_DEFAULT_IOSCHED, false); |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 219 | if (!e) { |
| 220 | printk(KERN_ERR |
| 221 | "Default I/O scheduler not found. " \ |
| 222 | "Using noop.\n"); |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 223 | e = elevator_get("noop", false); |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 224 | } |
Nate Diller | 5f00397 | 2006-01-24 10:07:58 +0100 | [diff] [blame] | 225 | } |
| 226 | |
Jianpeng Ma | d50235b | 2013-07-03 13:25:24 +0200 | [diff] [blame] | 227 | err = e->ops.elevator_init_fn(q, e); |
Sudip Mukherjee | d32f6b5 | 2014-10-23 22:16:48 +0530 | [diff] [blame] | 228 | if (err) |
| 229 | elevator_put(e); |
| 230 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 232 | EXPORT_SYMBOL(elevator_init); |
| 233 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 234 | void elevator_exit(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | { |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 236 | mutex_lock(&e->sysfs_lock); |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 237 | if (e->type->ops.elevator_exit_fn) |
| 238 | e->type->ops.elevator_exit_fn(e); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 239 | mutex_unlock(&e->sysfs_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 241 | kobject_put(&e->kobj); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 243 | EXPORT_SYMBOL(elevator_exit); |
| 244 | |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 245 | static inline void __elv_rqhash_del(struct request *rq) |
| 246 | { |
Sasha Levin | 242d98f | 2012-12-17 10:01:27 -0500 | [diff] [blame] | 247 | hash_del(&rq->hash); |
Jens Axboe | 360f92c | 2014-04-09 20:27:01 -0600 | [diff] [blame] | 248 | rq->cmd_flags &= ~REQ_HASHED; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 249 | } |
| 250 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 251 | static void elv_rqhash_del(struct request_queue *q, struct request *rq) |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 252 | { |
| 253 | if (ELV_ON_HASH(rq)) |
| 254 | __elv_rqhash_del(rq); |
| 255 | } |
| 256 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 257 | static void elv_rqhash_add(struct request_queue *q, struct request *rq) |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 258 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 259 | struct elevator_queue *e = q->elevator; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 260 | |
| 261 | BUG_ON(ELV_ON_HASH(rq)); |
Sasha Levin | 242d98f | 2012-12-17 10:01:27 -0500 | [diff] [blame] | 262 | hash_add(e->hash, &rq->hash, rq_hash_key(rq)); |
Jens Axboe | 360f92c | 2014-04-09 20:27:01 -0600 | [diff] [blame] | 263 | rq->cmd_flags |= REQ_HASHED; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 264 | } |
| 265 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 266 | static void elv_rqhash_reposition(struct request_queue *q, struct request *rq) |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 267 | { |
| 268 | __elv_rqhash_del(rq); |
| 269 | elv_rqhash_add(q, rq); |
| 270 | } |
| 271 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 272 | static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset) |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 273 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 274 | struct elevator_queue *e = q->elevator; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 275 | struct hlist_node *next; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 276 | struct request *rq; |
| 277 | |
Linus Torvalds | ee89f81 | 2013-02-28 12:52:24 -0800 | [diff] [blame] | 278 | hash_for_each_possible_safe(e->hash, rq, next, hash, offset) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 279 | BUG_ON(!ELV_ON_HASH(rq)); |
| 280 | |
| 281 | if (unlikely(!rq_mergeable(rq))) { |
| 282 | __elv_rqhash_del(rq); |
| 283 | continue; |
| 284 | } |
| 285 | |
| 286 | if (rq_hash_key(rq) == offset) |
| 287 | return rq; |
| 288 | } |
| 289 | |
| 290 | return NULL; |
| 291 | } |
| 292 | |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 293 | /* |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 294 | * RB-tree support functions for inserting/lookup/removal of requests |
| 295 | * in a sorted RB tree. |
| 296 | */ |
Jeff Moyer | 796d511 | 2011-06-02 21:19:05 +0200 | [diff] [blame] | 297 | void elv_rb_add(struct rb_root *root, struct request *rq) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 298 | { |
| 299 | struct rb_node **p = &root->rb_node; |
| 300 | struct rb_node *parent = NULL; |
| 301 | struct request *__rq; |
| 302 | |
| 303 | while (*p) { |
| 304 | parent = *p; |
| 305 | __rq = rb_entry(parent, struct request, rb_node); |
| 306 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 307 | if (blk_rq_pos(rq) < blk_rq_pos(__rq)) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 308 | p = &(*p)->rb_left; |
Jeff Moyer | 796d511 | 2011-06-02 21:19:05 +0200 | [diff] [blame] | 309 | else if (blk_rq_pos(rq) >= blk_rq_pos(__rq)) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 310 | p = &(*p)->rb_right; |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 311 | } |
| 312 | |
| 313 | rb_link_node(&rq->rb_node, parent, p); |
| 314 | rb_insert_color(&rq->rb_node, root); |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 315 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 316 | EXPORT_SYMBOL(elv_rb_add); |
| 317 | |
| 318 | void elv_rb_del(struct rb_root *root, struct request *rq) |
| 319 | { |
| 320 | BUG_ON(RB_EMPTY_NODE(&rq->rb_node)); |
| 321 | rb_erase(&rq->rb_node, root); |
| 322 | RB_CLEAR_NODE(&rq->rb_node); |
| 323 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 324 | EXPORT_SYMBOL(elv_rb_del); |
| 325 | |
| 326 | struct request *elv_rb_find(struct rb_root *root, sector_t sector) |
| 327 | { |
| 328 | struct rb_node *n = root->rb_node; |
| 329 | struct request *rq; |
| 330 | |
| 331 | while (n) { |
| 332 | rq = rb_entry(n, struct request, rb_node); |
| 333 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 334 | if (sector < blk_rq_pos(rq)) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 335 | n = n->rb_left; |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 336 | else if (sector > blk_rq_pos(rq)) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 337 | n = n->rb_right; |
| 338 | else |
| 339 | return rq; |
| 340 | } |
| 341 | |
| 342 | return NULL; |
| 343 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 344 | EXPORT_SYMBOL(elv_rb_find); |
| 345 | |
| 346 | /* |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 347 | * Insert rq into dispatch queue of q. Queue lock must be held on |
Uwe Kleine-König | dbe7f76 | 2007-10-20 01:55:04 +0200 | [diff] [blame] | 348 | * entry. rq is sort instead into the dispatch queue. To be used by |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 349 | * specific elevators. |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 350 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 351 | void elv_dispatch_sort(struct request_queue *q, struct request *rq) |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 352 | { |
| 353 | sector_t boundary; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 354 | struct list_head *entry; |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 355 | int stop_flags; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 356 | |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 357 | if (q->last_merge == rq) |
| 358 | q->last_merge = NULL; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 359 | |
| 360 | elv_rqhash_del(q, rq); |
| 361 | |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 362 | q->nr_sorted--; |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 363 | |
Jens Axboe | 1b47f53 | 2005-10-20 16:37:00 +0200 | [diff] [blame] | 364 | boundary = q->end_sector; |
Christoph Hellwig | 02e031c | 2010-11-10 14:54:09 +0100 | [diff] [blame] | 365 | stop_flags = REQ_SOFTBARRIER | REQ_STARTED; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 366 | list_for_each_prev(entry, &q->queue_head) { |
| 367 | struct request *pos = list_entry_rq(entry); |
| 368 | |
Adrian Hunter | 7afafc8 | 2016-08-16 10:59:35 +0300 | [diff] [blame] | 369 | if (req_op(rq) != req_op(pos)) |
David Woodhouse | e17fc0a | 2008-08-09 16:42:20 +0100 | [diff] [blame] | 370 | break; |
Jens Axboe | 783660b | 2007-01-19 11:27:47 +1100 | [diff] [blame] | 371 | if (rq_data_dir(rq) != rq_data_dir(pos)) |
| 372 | break; |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 373 | if (pos->cmd_flags & stop_flags) |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 374 | break; |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 375 | if (blk_rq_pos(rq) >= boundary) { |
| 376 | if (blk_rq_pos(pos) < boundary) |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 377 | continue; |
| 378 | } else { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 379 | if (blk_rq_pos(pos) >= boundary) |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 380 | break; |
| 381 | } |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 382 | if (blk_rq_pos(rq) >= blk_rq_pos(pos)) |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 383 | break; |
| 384 | } |
| 385 | |
| 386 | list_add(&rq->queuelist, entry); |
| 387 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 388 | EXPORT_SYMBOL(elv_dispatch_sort); |
| 389 | |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 390 | /* |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 391 | * Insert rq into dispatch queue of q. Queue lock must be held on |
| 392 | * entry. rq is added to the back of the dispatch queue. To be used by |
| 393 | * specific elevators. |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 394 | */ |
| 395 | void elv_dispatch_add_tail(struct request_queue *q, struct request *rq) |
| 396 | { |
| 397 | if (q->last_merge == rq) |
| 398 | q->last_merge = NULL; |
| 399 | |
| 400 | elv_rqhash_del(q, rq); |
| 401 | |
| 402 | q->nr_sorted--; |
| 403 | |
| 404 | q->end_sector = rq_end_sector(rq); |
| 405 | q->boundary_rq = rq; |
| 406 | list_add_tail(&rq->queuelist, &q->queue_head); |
| 407 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 408 | EXPORT_SYMBOL(elv_dispatch_add_tail); |
| 409 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 410 | int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 412 | struct elevator_queue *e = q->elevator; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 413 | struct request *__rq; |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 414 | int ret; |
| 415 | |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 416 | /* |
Alan D. Brunelle | 488991e | 2010-01-29 09:04:08 +0100 | [diff] [blame] | 417 | * Levels of merges: |
| 418 | * nomerges: No merges at all attempted |
| 419 | * noxmerges: Only simple one-hit cache try |
| 420 | * merges: All merge tries attempted |
| 421 | */ |
Ming Lei | 7460d38 | 2015-10-20 23:13:55 +0800 | [diff] [blame] | 422 | if (blk_queue_nomerges(q) || !bio_mergeable(bio)) |
Alan D. Brunelle | 488991e | 2010-01-29 09:04:08 +0100 | [diff] [blame] | 423 | return ELEVATOR_NO_MERGE; |
| 424 | |
| 425 | /* |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 426 | * First try one-hit cache. |
| 427 | */ |
Neeraj Soni | 36c6512 | 2018-04-18 21:04:46 +0530 | [diff] [blame] | 428 | if (q->last_merge) { |
| 429 | if (!elv_bio_merge_ok(q->last_merge, bio)) |
| 430 | return ELEVATOR_NO_MERGE; |
| 431 | |
Tejun Heo | 050c8ea | 2012-02-08 09:19:38 +0100 | [diff] [blame] | 432 | ret = blk_try_merge(q->last_merge, bio); |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 433 | if (ret != ELEVATOR_NO_MERGE) { |
| 434 | *req = q->last_merge; |
| 435 | return ret; |
| 436 | } |
| 437 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | |
Alan D. Brunelle | 488991e | 2010-01-29 09:04:08 +0100 | [diff] [blame] | 439 | if (blk_queue_noxmerges(q)) |
Alan D. Brunelle | ac9fafa | 2008-04-29 14:44:19 +0200 | [diff] [blame] | 440 | return ELEVATOR_NO_MERGE; |
| 441 | |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 442 | /* |
| 443 | * See if our hash lookup can find a potential backmerge. |
| 444 | */ |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 445 | __rq = elv_rqhash_find(q, bio->bi_iter.bi_sector); |
Tahsin Erdogan | 72ef799 | 2016-07-07 11:48:22 -0700 | [diff] [blame] | 446 | if (__rq && elv_bio_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 447 | *req = __rq; |
| 448 | return ELEVATOR_BACK_MERGE; |
| 449 | } |
| 450 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 451 | if (e->type->ops.elevator_merge_fn) |
| 452 | return e->type->ops.elevator_merge_fn(q, req, bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | |
| 454 | return ELEVATOR_NO_MERGE; |
| 455 | } |
| 456 | |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 457 | /* |
| 458 | * Attempt to do an insertion back merge. Only check for the case where |
| 459 | * we can append 'rq' to an existing request, so we can throw 'rq' away |
| 460 | * afterwards. |
| 461 | * |
| 462 | * Returns true if we merged, false otherwise |
| 463 | */ |
| 464 | static bool elv_attempt_insert_merge(struct request_queue *q, |
| 465 | struct request *rq) |
| 466 | { |
| 467 | struct request *__rq; |
Shaohua Li | bee0393 | 2012-11-09 08:44:27 +0100 | [diff] [blame] | 468 | bool ret; |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 469 | |
| 470 | if (blk_queue_nomerges(q)) |
| 471 | return false; |
| 472 | |
| 473 | /* |
| 474 | * First try one-hit cache. |
| 475 | */ |
| 476 | if (q->last_merge && blk_attempt_req_merge(q, q->last_merge, rq)) |
| 477 | return true; |
| 478 | |
| 479 | if (blk_queue_noxmerges(q)) |
| 480 | return false; |
| 481 | |
Shaohua Li | bee0393 | 2012-11-09 08:44:27 +0100 | [diff] [blame] | 482 | ret = false; |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 483 | /* |
| 484 | * See if our hash lookup can find a potential backmerge. |
| 485 | */ |
Shaohua Li | bee0393 | 2012-11-09 08:44:27 +0100 | [diff] [blame] | 486 | while (1) { |
| 487 | __rq = elv_rqhash_find(q, blk_rq_pos(rq)); |
| 488 | if (!__rq || !blk_attempt_req_merge(q, __rq, rq)) |
| 489 | break; |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 490 | |
Shaohua Li | bee0393 | 2012-11-09 08:44:27 +0100 | [diff] [blame] | 491 | /* The merged request could be merged with others, try again */ |
| 492 | ret = true; |
| 493 | rq = __rq; |
| 494 | } |
| 495 | |
| 496 | return ret; |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 497 | } |
| 498 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 499 | void elv_merged_request(struct request_queue *q, struct request *rq, int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 501 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 503 | if (e->type->ops.elevator_merged_fn) |
| 504 | e->type->ops.elevator_merged_fn(q, rq, type); |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 505 | |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 506 | if (type == ELEVATOR_BACK_MERGE) |
| 507 | elv_rqhash_reposition(q, rq); |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 508 | |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 509 | q->last_merge = rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | } |
| 511 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 512 | void elv_merge_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | struct request *next) |
| 514 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 515 | struct elevator_queue *e = q->elevator; |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 516 | const int next_sorted = next->cmd_flags & REQ_SORTED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 518 | if (next_sorted && e->type->ops.elevator_merge_req_fn) |
| 519 | e->type->ops.elevator_merge_req_fn(q, rq, next); |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 520 | |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 521 | elv_rqhash_reposition(q, rq); |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 522 | |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 523 | if (next_sorted) { |
| 524 | elv_rqhash_del(q, next); |
| 525 | q->nr_sorted--; |
| 526 | } |
| 527 | |
Tejun Heo | 06b8624 | 2005-10-20 16:46:23 +0200 | [diff] [blame] | 528 | q->last_merge = rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | } |
| 530 | |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 531 | void elv_bio_merged(struct request_queue *q, struct request *rq, |
| 532 | struct bio *bio) |
| 533 | { |
| 534 | struct elevator_queue *e = q->elevator; |
| 535 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 536 | if (e->type->ops.elevator_bio_merged_fn) |
| 537 | e->type->ops.elevator_bio_merged_fn(q, rq, bio); |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 538 | } |
| 539 | |
Rafael J. Wysocki | 47fafbc | 2014-12-04 01:00:23 +0100 | [diff] [blame] | 540 | #ifdef CONFIG_PM |
Lin Ming | c815881 | 2013-03-23 11:42:27 +0800 | [diff] [blame] | 541 | static void blk_pm_requeue_request(struct request *rq) |
| 542 | { |
| 543 | if (rq->q->dev && !(rq->cmd_flags & REQ_PM)) |
| 544 | rq->q->nr_pending--; |
| 545 | } |
| 546 | |
| 547 | static void blk_pm_add_request(struct request_queue *q, struct request *rq) |
| 548 | { |
| 549 | if (q->dev && !(rq->cmd_flags & REQ_PM) && q->nr_pending++ == 0 && |
| 550 | (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING)) |
| 551 | pm_request_resume(q->dev); |
| 552 | } |
| 553 | #else |
| 554 | static inline void blk_pm_requeue_request(struct request *rq) {} |
| 555 | static inline void blk_pm_add_request(struct request_queue *q, |
| 556 | struct request *rq) |
| 557 | { |
| 558 | } |
| 559 | #endif |
| 560 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 561 | void elv_requeue_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | /* |
| 564 | * it already went through dequeue, we need to decrement the |
| 565 | * in_flight count again |
| 566 | */ |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 567 | if (blk_account_rq(rq)) { |
Jens Axboe | 0a7ae2f | 2009-05-20 08:54:31 +0200 | [diff] [blame] | 568 | q->in_flight[rq_is_sync(rq)]--; |
Christoph Hellwig | 33659eb | 2010-08-07 18:17:56 +0200 | [diff] [blame] | 569 | if (rq->cmd_flags & REQ_SORTED) |
Jens Axboe | cad9751 | 2007-01-14 22:26:09 +1100 | [diff] [blame] | 570 | elv_deactivate_rq(q, rq); |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 571 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 573 | rq->cmd_flags &= ~REQ_STARTED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | |
Lin Ming | c815881 | 2013-03-23 11:42:27 +0800 | [diff] [blame] | 575 | blk_pm_requeue_request(rq); |
| 576 | |
Jens Axboe | b710a48 | 2011-03-30 09:52:30 +0200 | [diff] [blame] | 577 | __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | } |
| 579 | |
Jerome Marchand | 26308ea | 2009-03-27 10:31:51 +0100 | [diff] [blame] | 580 | void elv_drain_elevator(struct request_queue *q) |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 581 | { |
| 582 | static int printed; |
Tejun Heo | e3c78ca | 2011-10-19 14:32:38 +0200 | [diff] [blame] | 583 | |
| 584 | lockdep_assert_held(q->queue_lock); |
| 585 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 586 | while (q->elevator->type->ops.elevator_dispatch_fn(q, 1)) |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 587 | ; |
Tejun Heo | e3c78ca | 2011-10-19 14:32:38 +0200 | [diff] [blame] | 588 | if (q->nr_sorted && printed++ < 10) { |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 589 | printk(KERN_ERR "%s: forced dispatching is broken " |
| 590 | "(nr_sorted=%u), please report this\n", |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 591 | q->elevator->type->elevator_name, q->nr_sorted); |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 592 | } |
| 593 | } |
| 594 | |
Jens Axboe | b710a48 | 2011-03-30 09:52:30 +0200 | [diff] [blame] | 595 | void __elv_add_request(struct request_queue *q, struct request *rq, int where) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | { |
Arnaldo Carvalho de Melo | 5f3ea37 | 2008-10-30 08:34:33 +0100 | [diff] [blame] | 597 | trace_block_rq_insert(q, rq); |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 598 | |
Lin Ming | c815881 | 2013-03-23 11:42:27 +0800 | [diff] [blame] | 599 | blk_pm_add_request(q, rq); |
| 600 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | rq->q = q; |
| 602 | |
Jens Axboe | b710a48 | 2011-03-30 09:52:30 +0200 | [diff] [blame] | 603 | if (rq->cmd_flags & REQ_SOFTBARRIER) { |
| 604 | /* barriers are scheduling boundary, update end_sector */ |
Martin K. Petersen | e2a60da | 2012-09-18 12:19:25 -0400 | [diff] [blame] | 605 | if (rq->cmd_type == REQ_TYPE_FS) { |
Jens Axboe | b710a48 | 2011-03-30 09:52:30 +0200 | [diff] [blame] | 606 | q->end_sector = rq_end_sector(rq); |
| 607 | q->boundary_rq = rq; |
| 608 | } |
| 609 | } else if (!(rq->cmd_flags & REQ_ELVPRIV) && |
Jens Axboe | 3aa7287 | 2011-04-21 19:28:35 +0200 | [diff] [blame] | 610 | (where == ELEVATOR_INSERT_SORT || |
| 611 | where == ELEVATOR_INSERT_SORT_MERGE)) |
Jens Axboe | b710a48 | 2011-03-30 09:52:30 +0200 | [diff] [blame] | 612 | where = ELEVATOR_INSERT_BACK; |
| 613 | |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 614 | switch (where) { |
Tejun Heo | 28e7d18 | 2010-09-03 11:56:16 +0200 | [diff] [blame] | 615 | case ELEVATOR_INSERT_REQUEUE: |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 616 | case ELEVATOR_INSERT_FRONT: |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 617 | rq->cmd_flags |= REQ_SOFTBARRIER; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 618 | list_add(&rq->queuelist, &q->queue_head); |
| 619 | break; |
| 620 | |
| 621 | case ELEVATOR_INSERT_BACK: |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 622 | rq->cmd_flags |= REQ_SOFTBARRIER; |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 623 | elv_drain_elevator(q); |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 624 | list_add_tail(&rq->queuelist, &q->queue_head); |
| 625 | /* |
| 626 | * We kick the queue here for the following reasons. |
| 627 | * - The elevator might have returned NULL previously |
| 628 | * to delay requests and returned them now. As the |
| 629 | * queue wasn't empty before this request, ll_rw_blk |
| 630 | * won't run the queue on return, resulting in hang. |
| 631 | * - Usually, back inserted requests won't be merged |
| 632 | * with anything. There's no point in delaying queue |
| 633 | * processing. |
| 634 | */ |
Christoph Hellwig | 24ecfbe | 2011-04-18 11:41:33 +0200 | [diff] [blame] | 635 | __blk_run_queue(q); |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 636 | break; |
| 637 | |
Jens Axboe | 5e84ea3 | 2011-03-21 10:14:27 +0100 | [diff] [blame] | 638 | case ELEVATOR_INSERT_SORT_MERGE: |
| 639 | /* |
| 640 | * If we succeed in merging this request with one in the |
| 641 | * queue already, we are done - rq has now been freed, |
| 642 | * so no need to do anything further. |
| 643 | */ |
| 644 | if (elv_attempt_insert_merge(q, rq)) |
| 645 | break; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 646 | case ELEVATOR_INSERT_SORT: |
Martin K. Petersen | e2a60da | 2012-09-18 12:19:25 -0400 | [diff] [blame] | 647 | BUG_ON(rq->cmd_type != REQ_TYPE_FS); |
Jens Axboe | 4aff5e2 | 2006-08-10 08:44:47 +0200 | [diff] [blame] | 648 | rq->cmd_flags |= REQ_SORTED; |
Tejun Heo | 15853af | 2005-11-10 08:52:05 +0100 | [diff] [blame] | 649 | q->nr_sorted++; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 650 | if (rq_mergeable(rq)) { |
| 651 | elv_rqhash_add(q, rq); |
| 652 | if (!q->last_merge) |
| 653 | q->last_merge = rq; |
| 654 | } |
| 655 | |
Tejun Heo | ca23509 | 2005-11-01 17:23:49 +0900 | [diff] [blame] | 656 | /* |
| 657 | * Some ioscheds (cfq) run q->request_fn directly, so |
| 658 | * rq cannot be accessed after calling |
| 659 | * elevator_add_req_fn. |
| 660 | */ |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 661 | q->elevator->type->ops.elevator_add_req_fn(q, rq); |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 662 | break; |
| 663 | |
Tejun Heo | ae1b153 | 2011-01-25 12:43:54 +0100 | [diff] [blame] | 664 | case ELEVATOR_INSERT_FLUSH: |
| 665 | rq->cmd_flags |= REQ_SOFTBARRIER; |
| 666 | blk_insert_flush(rq); |
| 667 | break; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 668 | default: |
| 669 | printk(KERN_ERR "%s: bad insertion point %d\n", |
Harvey Harrison | 24c03d4 | 2008-05-01 04:35:17 -0700 | [diff] [blame] | 670 | __func__, where); |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 671 | BUG(); |
| 672 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 674 | EXPORT_SYMBOL(__elv_add_request); |
| 675 | |
Jens Axboe | 7eaceac | 2011-03-10 08:52:07 +0100 | [diff] [blame] | 676 | void elv_add_request(struct request_queue *q, struct request *rq, int where) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | { |
| 678 | unsigned long flags; |
| 679 | |
| 680 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 7eaceac | 2011-03-10 08:52:07 +0100 | [diff] [blame] | 681 | __elv_add_request(q, rq, where); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 683 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 684 | EXPORT_SYMBOL(elv_add_request); |
| 685 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 686 | struct request *elv_latter_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 688 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 690 | if (e->type->ops.elevator_latter_req_fn) |
| 691 | return e->type->ops.elevator_latter_req_fn(q, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | return NULL; |
| 693 | } |
| 694 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 695 | struct request *elv_former_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 697 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 699 | if (e->type->ops.elevator_former_req_fn) |
| 700 | return e->type->ops.elevator_former_req_fn(q, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | return NULL; |
| 702 | } |
| 703 | |
Tejun Heo | 852c788 | 2012-03-05 13:15:27 -0800 | [diff] [blame] | 704 | int elv_set_request(struct request_queue *q, struct request *rq, |
| 705 | struct bio *bio, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 707 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 709 | if (e->type->ops.elevator_set_req_fn) |
Tejun Heo | 852c788 | 2012-03-05 13:15:27 -0800 | [diff] [blame] | 710 | return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | return 0; |
| 712 | } |
| 713 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 714 | void elv_put_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 716 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 718 | if (e->type->ops.elevator_put_req_fn) |
| 719 | e->type->ops.elevator_put_req_fn(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | } |
| 721 | |
Mike Christie | ba568ea | 2016-06-05 14:32:13 -0500 | [diff] [blame] | 722 | int elv_may_queue(struct request_queue *q, int op, int op_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 724 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 726 | if (e->type->ops.elevator_may_queue_fn) |
Mike Christie | ba568ea | 2016-06-05 14:32:13 -0500 | [diff] [blame] | 727 | return e->type->ops.elevator_may_queue_fn(q, op, op_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | |
| 729 | return ELV_MQUEUE_MAY; |
| 730 | } |
| 731 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 732 | void elv_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 734 | struct elevator_queue *e = q->elevator; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | |
| 736 | /* |
| 737 | * request is released from the driver, io must be done |
| 738 | */ |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 739 | if (blk_account_rq(rq)) { |
Jens Axboe | 0a7ae2f | 2009-05-20 08:54:31 +0200 | [diff] [blame] | 740 | q->in_flight[rq_is_sync(rq)]--; |
Christoph Hellwig | 33659eb | 2010-08-07 18:17:56 +0200 | [diff] [blame] | 741 | if ((rq->cmd_flags & REQ_SORTED) && |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 742 | e->type->ops.elevator_completed_req_fn) |
| 743 | e->type->ops.elevator_completed_req_fn(q, rq); |
Tejun Heo | 1bc691d | 2006-01-12 15:39:26 +0100 | [diff] [blame] | 744 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | } |
| 746 | |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 747 | #define to_elv(atr) container_of((atr), struct elv_fs_entry, attr) |
| 748 | |
| 749 | static ssize_t |
| 750 | elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page) |
| 751 | { |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 752 | struct elv_fs_entry *entry = to_elv(attr); |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 753 | struct elevator_queue *e; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 754 | ssize_t error; |
| 755 | |
| 756 | if (!entry->show) |
| 757 | return -EIO; |
| 758 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 759 | e = container_of(kobj, struct elevator_queue, kobj); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 760 | mutex_lock(&e->sysfs_lock); |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 761 | error = e->type ? entry->show(e, page) : -ENOENT; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 762 | mutex_unlock(&e->sysfs_lock); |
| 763 | return error; |
| 764 | } |
| 765 | |
| 766 | static ssize_t |
| 767 | elv_attr_store(struct kobject *kobj, struct attribute *attr, |
| 768 | const char *page, size_t length) |
| 769 | { |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 770 | struct elv_fs_entry *entry = to_elv(attr); |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 771 | struct elevator_queue *e; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 772 | ssize_t error; |
| 773 | |
| 774 | if (!entry->store) |
| 775 | return -EIO; |
| 776 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 777 | e = container_of(kobj, struct elevator_queue, kobj); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 778 | mutex_lock(&e->sysfs_lock); |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 779 | error = e->type ? entry->store(e, page, length) : -ENOENT; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 780 | mutex_unlock(&e->sysfs_lock); |
| 781 | return error; |
| 782 | } |
| 783 | |
Emese Revfy | 52cf25d | 2010-01-19 02:58:23 +0100 | [diff] [blame] | 784 | static const struct sysfs_ops elv_sysfs_ops = { |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 785 | .show = elv_attr_show, |
| 786 | .store = elv_attr_store, |
| 787 | }; |
| 788 | |
| 789 | static struct kobj_type elv_ktype = { |
| 790 | .sysfs_ops = &elv_sysfs_ops, |
| 791 | .release = elevator_release, |
| 792 | }; |
| 793 | |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 794 | int elv_register_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | { |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 796 | struct elevator_queue *e = q->elevator; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 797 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | |
Greg Kroah-Hartman | b2d6db5 | 2007-12-17 23:05:35 -0700 | [diff] [blame] | 799 | error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched"); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 800 | if (!error) { |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 801 | struct elv_fs_entry *attr = e->type->elevator_attrs; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 802 | if (attr) { |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 803 | while (attr->attr.name) { |
| 804 | if (sysfs_create_file(&e->kobj, &attr->attr)) |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 805 | break; |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 806 | attr++; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 807 | } |
| 808 | } |
| 809 | kobject_uevent(&e->kobj, KOBJ_ADD); |
Jens Axboe | 430c62f | 2010-10-07 09:35:16 +0200 | [diff] [blame] | 810 | e->registered = 1; |
Jens Axboe | 0bb9794 | 2015-06-10 08:01:20 -0600 | [diff] [blame] | 811 | if (e->type->ops.elevator_registered_fn) |
| 812 | e->type->ops.elevator_registered_fn(q); |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 813 | } |
| 814 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | } |
Tejun Heo | f8fc877 | 2011-12-14 00:33:40 +0100 | [diff] [blame] | 816 | EXPORT_SYMBOL(elv_register_queue); |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 817 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | void elv_unregister_queue(struct request_queue *q) |
| 819 | { |
Tejun Heo | f8fc877 | 2011-12-14 00:33:40 +0100 | [diff] [blame] | 820 | if (q) { |
| 821 | struct elevator_queue *e = q->elevator; |
| 822 | |
| 823 | kobject_uevent(&e->kobj, KOBJ_REMOVE); |
| 824 | kobject_del(&e->kobj); |
| 825 | e->registered = 0; |
| 826 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } |
Mike Snitzer | 01effb0 | 2010-05-11 08:57:42 +0200 | [diff] [blame] | 828 | EXPORT_SYMBOL(elv_unregister_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | |
Jens Axboe | e567bf7 | 2014-06-22 16:32:48 -0600 | [diff] [blame] | 830 | int elv_register(struct elevator_type *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | { |
Thibaut VARENE | 1ffb96c | 2007-03-15 12:59:19 +0100 | [diff] [blame] | 832 | char *def = ""; |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 833 | |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 834 | /* create icq_cache if requested */ |
| 835 | if (e->icq_size) { |
| 836 | if (WARN_ON(e->icq_size < sizeof(struct io_cq)) || |
| 837 | WARN_ON(e->icq_align < __alignof__(struct io_cq))) |
| 838 | return -EINVAL; |
| 839 | |
| 840 | snprintf(e->icq_cache_name, sizeof(e->icq_cache_name), |
| 841 | "%s_io_cq", e->elevator_name); |
| 842 | e->icq_cache = kmem_cache_create(e->icq_cache_name, e->icq_size, |
| 843 | e->icq_align, 0, NULL); |
| 844 | if (!e->icq_cache) |
| 845 | return -ENOMEM; |
| 846 | } |
| 847 | |
| 848 | /* register, don't allow duplicate names */ |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 849 | spin_lock(&elv_list_lock); |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 850 | if (elevator_find(e->elevator_name)) { |
| 851 | spin_unlock(&elv_list_lock); |
| 852 | if (e->icq_cache) |
| 853 | kmem_cache_destroy(e->icq_cache); |
| 854 | return -EBUSY; |
| 855 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | list_add_tail(&e->list, &elv_list); |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 857 | spin_unlock(&elv_list_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 859 | /* print pretty message */ |
Nate Diller | 5f00397 | 2006-01-24 10:07:58 +0100 | [diff] [blame] | 860 | if (!strcmp(e->elevator_name, chosen_elevator) || |
| 861 | (!*chosen_elevator && |
| 862 | !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) |
Thibaut VARENE | 1ffb96c | 2007-03-15 12:59:19 +0100 | [diff] [blame] | 863 | def = " (default)"; |
| 864 | |
Jens Axboe | 4eb166d | 2008-02-01 00:37:27 +0100 | [diff] [blame] | 865 | printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, |
| 866 | def); |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 867 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | } |
| 869 | EXPORT_SYMBOL_GPL(elv_register); |
| 870 | |
| 871 | void elv_unregister(struct elevator_type *e) |
| 872 | { |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 873 | /* unregister */ |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 874 | spin_lock(&elv_list_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 875 | list_del_init(&e->list); |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 876 | spin_unlock(&elv_list_lock); |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 877 | |
| 878 | /* |
| 879 | * Destroy icq_cache if it exists. icq's are RCU managed. Make |
| 880 | * sure all RCU operations are complete before proceeding. |
| 881 | */ |
| 882 | if (e->icq_cache) { |
| 883 | rcu_barrier(); |
| 884 | kmem_cache_destroy(e->icq_cache); |
| 885 | e->icq_cache = NULL; |
| 886 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | } |
| 888 | EXPORT_SYMBOL_GPL(elv_unregister); |
| 889 | |
| 890 | /* |
| 891 | * switch to new_e io scheduler. be careful not to introduce deadlocks - |
| 892 | * we don't free the old io scheduler, before we have allocated what we |
| 893 | * need for the new one. this way we have a chance of going back to the old |
Tejun Heo | cb98fc8 | 2005-10-28 08:29:39 +0200 | [diff] [blame] | 894 | * one, if the new one fails init for some reason. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 896 | static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | { |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 898 | struct elevator_queue *old = q->elevator; |
| 899 | bool registered = old->registered; |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 900 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 902 | /* |
| 903 | * Turn on BYPASS and drain all requests w/ elevator private data. |
| 904 | * Block layer doesn't call into a quiesced elevator - all requests |
| 905 | * are directly put on the dispatch list without elevator data |
| 906 | * using INSERT_BACK. All requests have SOFTBARRIER set and no |
| 907 | * merge happens either. |
| 908 | */ |
Tejun Heo | d732580 | 2012-03-05 13:14:58 -0800 | [diff] [blame] | 909 | blk_queue_bypass_start(q); |
Tejun Heo | cb98fc8 | 2005-10-28 08:29:39 +0200 | [diff] [blame] | 910 | |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 911 | /* unregister and clear all auxiliary data of the old elevator */ |
| 912 | if (registered) |
Tejun Heo | f8fc877 | 2011-12-14 00:33:40 +0100 | [diff] [blame] | 913 | elv_unregister_queue(q); |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 914 | |
| 915 | spin_lock_irq(q->queue_lock); |
| 916 | ioc_clear_queue(q); |
| 917 | spin_unlock_irq(q->queue_lock); |
| 918 | |
| 919 | /* allocate, init and register new elevator */ |
Jianpeng Ma | d50235b | 2013-07-03 13:25:24 +0200 | [diff] [blame] | 920 | err = new_e->ops.elevator_init_fn(q, new_e); |
| 921 | if (err) |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 922 | goto fail_init; |
| 923 | |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 924 | if (registered) { |
| 925 | err = elv_register_queue(q); |
Jens Axboe | 430c62f | 2010-10-07 09:35:16 +0200 | [diff] [blame] | 926 | if (err) |
| 927 | goto fail_register; |
| 928 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 930 | /* done, kill the old one and finish */ |
| 931 | elevator_exit(old); |
Tejun Heo | d732580 | 2012-03-05 13:14:58 -0800 | [diff] [blame] | 932 | blk_queue_bypass_end(q); |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 933 | |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 934 | blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name); |
Alan D. Brunelle | 4722dc5 | 2008-05-27 14:55:00 +0200 | [diff] [blame] | 935 | |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 936 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 937 | |
| 938 | fail_register: |
Tejun Heo | 5a5bafd | 2012-03-05 13:14:56 -0800 | [diff] [blame] | 939 | elevator_exit(q->elevator); |
| 940 | fail_init: |
| 941 | /* switch failed, restore and re-register old elevator */ |
| 942 | q->elevator = old; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | elv_register_queue(q); |
Tejun Heo | d732580 | 2012-03-05 13:14:58 -0800 | [diff] [blame] | 944 | blk_queue_bypass_end(q); |
Nick Piggin | 75ad23b | 2008-04-29 14:48:33 +0200 | [diff] [blame] | 945 | |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 946 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | } |
| 948 | |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 949 | /* |
| 950 | * Switch this queue to the given IO scheduler. |
| 951 | */ |
Tomoki Sekiyama | 7c8a367 | 2013-10-15 16:42:19 -0600 | [diff] [blame] | 952 | static int __elevator_change(struct request_queue *q, const char *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | { |
| 954 | char elevator_name[ELV_NAME_MAX]; |
| 955 | struct elevator_type *e; |
| 956 | |
Martin K. Petersen | cd43e26 | 2009-05-22 17:17:52 -0400 | [diff] [blame] | 957 | if (!q->elevator) |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 958 | return -ENXIO; |
Martin K. Petersen | cd43e26 | 2009-05-22 17:17:52 -0400 | [diff] [blame] | 959 | |
Li Zefan | ee2e992 | 2008-10-14 08:49:56 +0200 | [diff] [blame] | 960 | strlcpy(elevator_name, name, sizeof(elevator_name)); |
Tejun Heo | 21c3c5d | 2013-01-22 16:48:03 -0800 | [diff] [blame] | 961 | e = elevator_get(strstrip(elevator_name), true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | if (!e) { |
| 963 | printk(KERN_ERR "elevator: type %s not found\n", elevator_name); |
| 964 | return -EINVAL; |
| 965 | } |
| 966 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 967 | if (!strcmp(elevator_name, q->elevator->type->elevator_name)) { |
Nate Diller | 2ca7d93 | 2005-10-30 15:02:24 -0800 | [diff] [blame] | 968 | elevator_put(e); |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 969 | return 0; |
Nate Diller | 2ca7d93 | 2005-10-30 15:02:24 -0800 | [diff] [blame] | 970 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 972 | return elevator_switch(q, e); |
| 973 | } |
Tomoki Sekiyama | 7c8a367 | 2013-10-15 16:42:19 -0600 | [diff] [blame] | 974 | |
| 975 | int elevator_change(struct request_queue *q, const char *name) |
| 976 | { |
| 977 | int ret; |
| 978 | |
| 979 | /* Protect q->elevator from elevator_init() */ |
| 980 | mutex_lock(&q->sysfs_lock); |
| 981 | ret = __elevator_change(q, name); |
| 982 | mutex_unlock(&q->sysfs_lock); |
| 983 | |
| 984 | return ret; |
| 985 | } |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 986 | EXPORT_SYMBOL(elevator_change); |
| 987 | |
| 988 | ssize_t elv_iosched_store(struct request_queue *q, const char *name, |
| 989 | size_t count) |
| 990 | { |
| 991 | int ret; |
| 992 | |
| 993 | if (!q->elevator) |
| 994 | return count; |
| 995 | |
Tomoki Sekiyama | 7c8a367 | 2013-10-15 16:42:19 -0600 | [diff] [blame] | 996 | ret = __elevator_change(q, name); |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 997 | if (!ret) |
| 998 | return count; |
| 999 | |
| 1000 | printk(KERN_ERR "elevator: switch to %s failed\n", name); |
| 1001 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | } |
| 1003 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1004 | ssize_t elv_iosched_show(struct request_queue *q, char *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | { |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 1006 | struct elevator_queue *e = q->elevator; |
Martin K. Petersen | cd43e26 | 2009-05-22 17:17:52 -0400 | [diff] [blame] | 1007 | struct elevator_type *elv; |
Matthias Kaehlcke | 70cee26 | 2007-07-10 12:26:24 +0200 | [diff] [blame] | 1008 | struct elevator_type *__e; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | int len = 0; |
| 1010 | |
Mike Snitzer | e36f724 | 2010-05-24 09:07:32 +0200 | [diff] [blame] | 1011 | if (!q->elevator || !blk_queue_stackable(q)) |
Martin K. Petersen | cd43e26 | 2009-05-22 17:17:52 -0400 | [diff] [blame] | 1012 | return sprintf(name, "none\n"); |
| 1013 | |
Tejun Heo | 22f746e | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 1014 | elv = e->type; |
Martin K. Petersen | cd43e26 | 2009-05-22 17:17:52 -0400 | [diff] [blame] | 1015 | |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 1016 | spin_lock(&elv_list_lock); |
Matthias Kaehlcke | 70cee26 | 2007-07-10 12:26:24 +0200 | [diff] [blame] | 1017 | list_for_each_entry(__e, &elv_list, list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | if (!strcmp(elv->elevator_name, __e->elevator_name)) |
| 1019 | len += sprintf(name+len, "[%s] ", elv->elevator_name); |
| 1020 | else |
| 1021 | len += sprintf(name+len, "%s ", __e->elevator_name); |
| 1022 | } |
Jens Axboe | 2a12dcd | 2007-04-26 14:41:53 +0200 | [diff] [blame] | 1023 | spin_unlock(&elv_list_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1024 | |
| 1025 | len += sprintf(len+name, "\n"); |
| 1026 | return len; |
| 1027 | } |
| 1028 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1029 | struct request *elv_rb_former_request(struct request_queue *q, |
| 1030 | struct request *rq) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 1031 | { |
| 1032 | struct rb_node *rbprev = rb_prev(&rq->rb_node); |
| 1033 | |
| 1034 | if (rbprev) |
| 1035 | return rb_entry_rq(rbprev); |
| 1036 | |
| 1037 | return NULL; |
| 1038 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 1039 | EXPORT_SYMBOL(elv_rb_former_request); |
| 1040 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1041 | struct request *elv_rb_latter_request(struct request_queue *q, |
| 1042 | struct request *rq) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 1043 | { |
| 1044 | struct rb_node *rbnext = rb_next(&rq->rb_node); |
| 1045 | |
| 1046 | if (rbnext) |
| 1047 | return rb_entry_rq(rbnext); |
| 1048 | |
| 1049 | return NULL; |
| 1050 | } |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 1051 | EXPORT_SYMBOL(elv_rb_latter_request); |