Christoph Hellwig | 3dcf60b | 2019-04-30 14:42:43 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 2 | /* |
| 3 | * Common Block IO controller cgroup interface |
| 4 | * |
| 5 | * Based on ideas and code from CFQ, CFS and BFQ: |
| 6 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
| 7 | * |
| 8 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> |
| 9 | * Paolo Valente <paolo.valente@unimore.it> |
| 10 | * |
| 11 | * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> |
| 12 | * Nauman Rafique <nauman@google.com> |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 13 | * |
| 14 | * For policy-specific per-blkcg data: |
| 15 | * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it> |
| 16 | * Arianna Avanzini <avanzini.arianna@gmail.com> |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 17 | */ |
| 18 | #include <linux/ioprio.h> |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 19 | #include <linux/kdev_t.h> |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 20 | #include <linux/module.h> |
Ingo Molnar | 174cd4b | 2017-02-02 19:15:33 +0100 | [diff] [blame] | 21 | #include <linux/sched/signal.h> |
Stephen Rothwell | accee78 | 2009-12-07 19:29:39 +1100 | [diff] [blame] | 22 | #include <linux/err.h> |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 23 | #include <linux/blkdev.h> |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 24 | #include <linux/backing-dev.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 25 | #include <linux/slab.h> |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 26 | #include <linux/genhd.h> |
Tejun Heo | 72e06c2 | 2012-03-05 13:15:00 -0800 | [diff] [blame] | 27 | #include <linux/delay.h> |
Tejun Heo | 9a9e8a2 | 2012-03-19 15:10:56 -0700 | [diff] [blame] | 28 | #include <linux/atomic.h> |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 29 | #include <linux/ctype.h> |
Tejun Heo | eea8f41 | 2015-05-22 17:13:17 -0400 | [diff] [blame] | 30 | #include <linux/blk-cgroup.h> |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 31 | #include <linux/tracehook.h> |
Josef Bacik | fd112c7 | 2019-07-09 14:41:29 -0700 | [diff] [blame] | 32 | #include <linux/psi.h> |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 33 | #include "blk.h" |
Bart Van Assche | 556910e | 2021-06-17 17:44:44 -0700 | [diff] [blame] | 34 | #include "blk-ioprio.h" |
Jens Axboe | a7b36ee | 2021-10-05 09:11:56 -0600 | [diff] [blame] | 35 | #include "blk-throttle.h" |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 36 | |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 37 | /* |
| 38 | * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation. |
| 39 | * blkcg_pol_register_mutex nests outside of it and synchronizes entire |
| 40 | * policy [un]register operations including cgroup file additions / |
| 41 | * removals. Putting cgroup file registration outside blkcg_pol_mutex |
| 42 | * allows grabbing it from cgroup callbacks. |
| 43 | */ |
| 44 | static DEFINE_MUTEX(blkcg_pol_register_mutex); |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 45 | static DEFINE_MUTEX(blkcg_pol_mutex); |
Tejun Heo | 923adde | 2012-03-05 13:15:13 -0800 | [diff] [blame] | 46 | |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 47 | struct blkcg blkcg_root; |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 48 | EXPORT_SYMBOL_GPL(blkcg_root); |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 49 | |
Tejun Heo | 496d5e7 | 2015-05-22 17:13:21 -0400 | [diff] [blame] | 50 | struct cgroup_subsys_state * const blkcg_root_css = &blkcg_root.css; |
Tejun Heo | 9b0eb69 | 2019-06-27 13:39:48 -0700 | [diff] [blame] | 51 | EXPORT_SYMBOL_GPL(blkcg_root_css); |
Tejun Heo | 496d5e7 | 2015-05-22 17:13:21 -0400 | [diff] [blame] | 52 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 53 | static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS]; |
Tejun Heo | 035d10b | 2012-03-05 13:15:04 -0800 | [diff] [blame] | 54 | |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 55 | static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */ |
| 56 | |
Tejun Heo | 07b0fde | 2019-07-16 07:58:31 -0700 | [diff] [blame] | 57 | bool blkcg_debug_stats = false; |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 58 | static struct workqueue_struct *blkcg_punt_bio_wq; |
Josef Bacik | 903d23f | 2018-07-03 11:14:52 -0400 | [diff] [blame] | 59 | |
Yu Kuai | a731763 | 2021-07-07 09:56:49 +0800 | [diff] [blame] | 60 | #define BLKG_DESTROY_BATCH_SIZE 64 |
| 61 | |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 62 | static bool blkcg_policy_enabled(struct request_queue *q, |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 63 | const struct blkcg_policy *pol) |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 64 | { |
| 65 | return pol && test_bit(pol->plid, q->blkcg_pols); |
| 66 | } |
| 67 | |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 68 | /** |
| 69 | * blkg_free - free a blkg |
| 70 | * @blkg: blkg to free |
| 71 | * |
| 72 | * Free @blkg which may be partially allocated. |
| 73 | */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 74 | static void blkg_free(struct blkcg_gq *blkg) |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 75 | { |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 76 | int i; |
Tejun Heo | 549d3aa | 2012-03-05 13:15:16 -0800 | [diff] [blame] | 77 | |
| 78 | if (!blkg) |
| 79 | return; |
| 80 | |
Tejun Heo | db61367 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 81 | for (i = 0; i < BLKCG_MAX_POLS; i++) |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 82 | if (blkg->pd[i]) |
| 83 | blkcg_policy[i]->pd_free_fn(blkg->pd[i]); |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 84 | |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 85 | free_percpu(blkg->iostat_cpu); |
Tejun Heo | ef069b9 | 2019-06-13 15:30:39 -0700 | [diff] [blame] | 86 | percpu_ref_exit(&blkg->refcnt); |
Tejun Heo | 549d3aa | 2012-03-05 13:15:16 -0800 | [diff] [blame] | 87 | kfree(blkg); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 88 | } |
| 89 | |
Dennis Zhou | 7fcf2b0 | 2018-12-05 12:10:38 -0500 | [diff] [blame] | 90 | static void __blkg_release(struct rcu_head *rcu) |
| 91 | { |
| 92 | struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head); |
| 93 | |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 94 | WARN_ON(!bio_list_empty(&blkg->async_bios)); |
| 95 | |
Dennis Zhou | 7fcf2b0 | 2018-12-05 12:10:38 -0500 | [diff] [blame] | 96 | /* release the blkcg and parent blkg refs this blkg has been holding */ |
| 97 | css_put(&blkg->blkcg->css); |
| 98 | if (blkg->parent) |
| 99 | blkg_put(blkg->parent); |
Dennis Zhou | 7fcf2b0 | 2018-12-05 12:10:38 -0500 | [diff] [blame] | 100 | blkg_free(blkg); |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * A group is RCU protected, but having an rcu lock does not mean that one |
| 105 | * can access all the fields of blkg and assume these are valid. For |
| 106 | * example, don't try to follow throtl_data and request queue links. |
| 107 | * |
| 108 | * Having a reference to blkg under an rcu allows accesses to only values |
| 109 | * local to groups like group stats and group rate limits. |
| 110 | */ |
| 111 | static void blkg_release(struct percpu_ref *ref) |
| 112 | { |
| 113 | struct blkcg_gq *blkg = container_of(ref, struct blkcg_gq, refcnt); |
| 114 | |
| 115 | call_rcu(&blkg->rcu_head, __blkg_release); |
| 116 | } |
| 117 | |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 118 | static void blkg_async_bio_workfn(struct work_struct *work) |
| 119 | { |
| 120 | struct blkcg_gq *blkg = container_of(work, struct blkcg_gq, |
| 121 | async_bio_work); |
| 122 | struct bio_list bios = BIO_EMPTY_LIST; |
| 123 | struct bio *bio; |
Xianting Tian | 192f1c6 | 2020-09-10 14:15:06 +0800 | [diff] [blame] | 124 | struct blk_plug plug; |
| 125 | bool need_plug = false; |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 126 | |
| 127 | /* as long as there are pending bios, @blkg can't go away */ |
| 128 | spin_lock_bh(&blkg->async_bio_lock); |
| 129 | bio_list_merge(&bios, &blkg->async_bios); |
| 130 | bio_list_init(&blkg->async_bios); |
| 131 | spin_unlock_bh(&blkg->async_bio_lock); |
| 132 | |
Xianting Tian | 192f1c6 | 2020-09-10 14:15:06 +0800 | [diff] [blame] | 133 | /* start plug only when bio_list contains at least 2 bios */ |
| 134 | if (bios.head && bios.head->bi_next) { |
| 135 | need_plug = true; |
| 136 | blk_start_plug(&plug); |
| 137 | } |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 138 | while ((bio = bio_list_pop(&bios))) |
| 139 | submit_bio(bio); |
Xianting Tian | 192f1c6 | 2020-09-10 14:15:06 +0800 | [diff] [blame] | 140 | if (need_plug) |
| 141 | blk_finish_plug(&plug); |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 142 | } |
| 143 | |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 144 | /** |
| 145 | * blkg_alloc - allocate a blkg |
| 146 | * @blkcg: block cgroup the new blkg is associated with |
| 147 | * @q: request_queue the new blkg is associated with |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 148 | * @gfp_mask: allocation mask to use |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 149 | * |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 150 | * Allocate a new blkg assocating @blkcg and @q. |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 151 | */ |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 152 | static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q, |
| 153 | gfp_t gfp_mask) |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 154 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 155 | struct blkcg_gq *blkg; |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 156 | int i, cpu; |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 157 | |
| 158 | /* alloc and init base part */ |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 159 | blkg = kzalloc_node(sizeof(*blkg), gfp_mask, q->node); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 160 | if (!blkg) |
| 161 | return NULL; |
| 162 | |
Tejun Heo | ef069b9 | 2019-06-13 15:30:39 -0700 | [diff] [blame] | 163 | if (percpu_ref_init(&blkg->refcnt, blkg_release, 0, gfp_mask)) |
| 164 | goto err_free; |
| 165 | |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 166 | blkg->iostat_cpu = alloc_percpu_gfp(struct blkg_iostat_set, gfp_mask); |
| 167 | if (!blkg->iostat_cpu) |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 168 | goto err_free; |
| 169 | |
Tejun Heo | c875f4d | 2012-03-05 13:15:22 -0800 | [diff] [blame] | 170 | blkg->q = q; |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 171 | INIT_LIST_HEAD(&blkg->q_node); |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 172 | spin_lock_init(&blkg->async_bio_lock); |
| 173 | bio_list_init(&blkg->async_bios); |
| 174 | INIT_WORK(&blkg->async_bio_work, blkg_async_bio_workfn); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 175 | blkg->blkcg = blkcg; |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 176 | |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 177 | u64_stats_init(&blkg->iostat.sync); |
| 178 | for_each_possible_cpu(cpu) |
| 179 | u64_stats_init(&per_cpu_ptr(blkg->iostat_cpu, cpu)->sync); |
| 180 | |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 181 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 182 | struct blkcg_policy *pol = blkcg_policy[i]; |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 183 | struct blkg_policy_data *pd; |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 184 | |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 185 | if (!blkcg_policy_enabled(q, pol)) |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 186 | continue; |
Tejun Heo | 549d3aa | 2012-03-05 13:15:16 -0800 | [diff] [blame] | 187 | |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 188 | /* alloc per-policy data and attach it to blkg */ |
Tejun Heo | cf09a8e | 2019-08-28 15:05:51 -0700 | [diff] [blame] | 189 | pd = pol->pd_alloc_fn(gfp_mask, q, blkcg); |
Tejun Heo | a051661 | 2012-06-26 15:05:44 -0700 | [diff] [blame] | 190 | if (!pd) |
| 191 | goto err_free; |
Tejun Heo | 549d3aa | 2012-03-05 13:15:16 -0800 | [diff] [blame] | 192 | |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 193 | blkg->pd[i] = pd; |
| 194 | pd->blkg = blkg; |
Tejun Heo | b276a87 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 195 | pd->plid = i; |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 196 | } |
| 197 | |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 198 | return blkg; |
Tejun Heo | a051661 | 2012-06-26 15:05:44 -0700 | [diff] [blame] | 199 | |
| 200 | err_free: |
| 201 | blkg_free(blkg); |
| 202 | return NULL; |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 203 | } |
| 204 | |
Tejun Heo | 24f2904 | 2015-08-18 14:55:17 -0700 | [diff] [blame] | 205 | struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg, |
| 206 | struct request_queue *q, bool update_hint) |
Tejun Heo | 80fd997 | 2012-04-13 14:50:53 -0700 | [diff] [blame] | 207 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 208 | struct blkcg_gq *blkg; |
Tejun Heo | 80fd997 | 2012-04-13 14:50:53 -0700 | [diff] [blame] | 209 | |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 210 | /* |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 211 | * Hint didn't match. Look up from the radix tree. Note that the |
| 212 | * hint can only be updated under queue_lock as otherwise @blkg |
| 213 | * could have already been removed from blkg_tree. The caller is |
| 214 | * responsible for grabbing queue_lock if @update_hint. |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 215 | */ |
| 216 | blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id); |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 217 | if (blkg && blkg->q == q) { |
| 218 | if (update_hint) { |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 219 | lockdep_assert_held(&q->queue_lock); |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 220 | rcu_assign_pointer(blkcg->blkg_hint, blkg); |
| 221 | } |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 222 | return blkg; |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 223 | } |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 224 | |
Tejun Heo | 80fd997 | 2012-04-13 14:50:53 -0700 | [diff] [blame] | 225 | return NULL; |
| 226 | } |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 227 | EXPORT_SYMBOL_GPL(blkg_lookup_slowpath); |
Tejun Heo | 80fd997 | 2012-04-13 14:50:53 -0700 | [diff] [blame] | 228 | |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 229 | /* |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 230 | * If @new_blkg is %NULL, this function tries to allocate a new one as |
| 231 | * necessary using %GFP_NOWAIT. @new_blkg is always consumed on return. |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 232 | */ |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 233 | static struct blkcg_gq *blkg_create(struct blkcg *blkcg, |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 234 | struct request_queue *q, |
| 235 | struct blkcg_gq *new_blkg) |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 236 | { |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 237 | struct blkcg_gq *blkg; |
Tejun Heo | f427d90 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 238 | int i, ret; |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 239 | |
Tejun Heo | cd1604f | 2012-03-05 13:15:06 -0800 | [diff] [blame] | 240 | WARN_ON_ONCE(!rcu_read_lock_held()); |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 241 | lockdep_assert_held(&q->queue_lock); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 242 | |
Dennis Zhou | 0273ac3 | 2018-12-11 18:03:08 -0500 | [diff] [blame] | 243 | /* request_queue is dying, do not create/recreate a blkg */ |
| 244 | if (blk_queue_dying(q)) { |
| 245 | ret = -ENODEV; |
| 246 | goto err_free_blkg; |
| 247 | } |
| 248 | |
Tejun Heo | 7ee9c56 | 2012-03-05 13:15:11 -0800 | [diff] [blame] | 249 | /* blkg holds a reference to blkcg */ |
Tejun Heo | ec903c0 | 2014-05-13 12:11:01 -0400 | [diff] [blame] | 250 | if (!css_tryget_online(&blkcg->css)) { |
Tejun Heo | 20386ce | 2015-08-18 14:55:28 -0700 | [diff] [blame] | 251 | ret = -ENODEV; |
Tejun Heo | 93e6d5d | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 252 | goto err_free_blkg; |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 253 | } |
Tejun Heo | cd1604f | 2012-03-05 13:15:06 -0800 | [diff] [blame] | 254 | |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 255 | /* allocate */ |
| 256 | if (!new_blkg) { |
| 257 | new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT | __GFP_NOWARN); |
| 258 | if (unlikely(!new_blkg)) { |
| 259 | ret = -ENOMEM; |
Christoph Hellwig | 8c911f3 | 2020-07-01 11:06:21 +0200 | [diff] [blame] | 260 | goto err_put_css; |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 261 | } |
| 262 | } |
| 263 | blkg = new_blkg; |
Tahsin Erdogan | 7fc6b87 | 2017-03-09 00:05:31 -0800 | [diff] [blame] | 264 | |
Tejun Heo | db61367 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 265 | /* link parent */ |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 266 | if (blkcg_parent(blkcg)) { |
| 267 | blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false); |
| 268 | if (WARN_ON_ONCE(!blkg->parent)) { |
Tejun Heo | 20386ce | 2015-08-18 14:55:28 -0700 | [diff] [blame] | 269 | ret = -ENODEV; |
Christoph Hellwig | 8c911f3 | 2020-07-01 11:06:21 +0200 | [diff] [blame] | 270 | goto err_put_css; |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 271 | } |
| 272 | blkg_get(blkg->parent); |
| 273 | } |
| 274 | |
Tejun Heo | db61367 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 275 | /* invoke per-policy init */ |
| 276 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
| 277 | struct blkcg_policy *pol = blkcg_policy[i]; |
| 278 | |
| 279 | if (blkg->pd[i] && pol->pd_init_fn) |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 280 | pol->pd_init_fn(blkg->pd[i]); |
Tejun Heo | db61367 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 281 | } |
| 282 | |
| 283 | /* insert */ |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 284 | spin_lock(&blkcg->lock); |
| 285 | ret = radix_tree_insert(&blkcg->blkg_tree, q->id, blkg); |
| 286 | if (likely(!ret)) { |
| 287 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); |
| 288 | list_add(&blkg->q_node, &q->blkg_list); |
Tejun Heo | f427d90 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 289 | |
| 290 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
| 291 | struct blkcg_policy *pol = blkcg_policy[i]; |
| 292 | |
| 293 | if (blkg->pd[i] && pol->pd_online_fn) |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 294 | pol->pd_online_fn(blkg->pd[i]); |
Tejun Heo | f427d90 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 295 | } |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 296 | } |
Tejun Heo | f427d90 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 297 | blkg->online = true; |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 298 | spin_unlock(&blkcg->lock); |
| 299 | |
Tejun Heo | ec13b1d | 2015-05-22 17:13:19 -0400 | [diff] [blame] | 300 | if (!ret) |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 301 | return blkg; |
Tejun Heo | 1597499 | 2012-06-04 20:40:52 -0700 | [diff] [blame] | 302 | |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 303 | /* @blkg failed fully initialized, use the usual release path */ |
| 304 | blkg_put(blkg); |
| 305 | return ERR_PTR(ret); |
| 306 | |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 307 | err_put_css: |
Tejun Heo | 496fb78 | 2012-04-19 16:29:23 -0700 | [diff] [blame] | 308 | css_put(&blkcg->css); |
Tejun Heo | 93e6d5d | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 309 | err_free_blkg: |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 310 | blkg_free(new_blkg); |
Tejun Heo | 93e6d5d | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 311 | return ERR_PTR(ret); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 312 | } |
Tejun Heo | 3c96cb3 | 2012-04-13 13:11:34 -0700 | [diff] [blame] | 313 | |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 314 | /** |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 315 | * blkg_lookup_create - lookup blkg, try to create one if not there |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 316 | * @blkcg: blkcg of interest |
| 317 | * @q: request_queue of interest |
| 318 | * |
| 319 | * Lookup blkg for the @blkcg - @q pair. If it doesn't exist, try to |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 320 | * create one. blkg creation is performed recursively from blkcg_root such |
| 321 | * that all non-root blkg's have access to the parent blkg. This function |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 322 | * should be called under RCU read lock and takes @q->queue_lock. |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 323 | * |
Dennis Zhou | beea9da | 2018-12-05 12:10:28 -0500 | [diff] [blame] | 324 | * Returns the blkg or the closest blkg if blkg_create() fails as it walks |
| 325 | * down from root. |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 326 | */ |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 327 | static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, |
| 328 | struct request_queue *q) |
Tejun Heo | 3c96cb3 | 2012-04-13 13:11:34 -0700 | [diff] [blame] | 329 | { |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 330 | struct blkcg_gq *blkg; |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 331 | unsigned long flags; |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 332 | |
| 333 | WARN_ON_ONCE(!rcu_read_lock_held()); |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 334 | |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 335 | blkg = blkg_lookup(blkcg, q); |
Tejun Heo | 86cde6b | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 336 | if (blkg) |
| 337 | return blkg; |
| 338 | |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 339 | spin_lock_irqsave(&q->queue_lock, flags); |
| 340 | blkg = __blkg_lookup(blkcg, q, true); |
| 341 | if (blkg) |
| 342 | goto found; |
| 343 | |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 344 | /* |
| 345 | * Create blkgs walking down from blkcg_root to @blkcg, so that all |
Dennis Zhou | beea9da | 2018-12-05 12:10:28 -0500 | [diff] [blame] | 346 | * non-root blkgs have access to their parents. Returns the closest |
| 347 | * blkg to the intended blkg should blkg_create() fail. |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 348 | */ |
| 349 | while (true) { |
| 350 | struct blkcg *pos = blkcg; |
| 351 | struct blkcg *parent = blkcg_parent(blkcg); |
Dennis Zhou | beea9da | 2018-12-05 12:10:28 -0500 | [diff] [blame] | 352 | struct blkcg_gq *ret_blkg = q->root_blkg; |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 353 | |
Dennis Zhou | beea9da | 2018-12-05 12:10:28 -0500 | [diff] [blame] | 354 | while (parent) { |
| 355 | blkg = __blkg_lookup(parent, q, false); |
| 356 | if (blkg) { |
| 357 | /* remember closest blkg */ |
| 358 | ret_blkg = blkg; |
| 359 | break; |
| 360 | } |
Tejun Heo | 3c54786 | 2013-01-09 08:05:10 -0800 | [diff] [blame] | 361 | pos = parent; |
| 362 | parent = blkcg_parent(parent); |
| 363 | } |
| 364 | |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 365 | blkg = blkg_create(pos, q, NULL); |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 366 | if (IS_ERR(blkg)) { |
| 367 | blkg = ret_blkg; |
| 368 | break; |
| 369 | } |
Dennis Zhou | beea9da | 2018-12-05 12:10:28 -0500 | [diff] [blame] | 370 | if (pos == blkcg) |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 371 | break; |
Dennis Zhou | b978962 | 2018-12-05 12:10:27 -0500 | [diff] [blame] | 372 | } |
| 373 | |
Christoph Hellwig | 8c54628 | 2020-06-27 09:31:52 +0200 | [diff] [blame] | 374 | found: |
| 375 | spin_unlock_irqrestore(&q->queue_lock, flags); |
Dennis Zhou | b978962 | 2018-12-05 12:10:27 -0500 | [diff] [blame] | 376 | return blkg; |
| 377 | } |
| 378 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 379 | static void blkg_destroy(struct blkcg_gq *blkg) |
Tejun Heo | 72e06c2 | 2012-03-05 13:15:00 -0800 | [diff] [blame] | 380 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 381 | struct blkcg *blkcg = blkg->blkcg; |
Dennis Zhou (Facebook) | 6b06546 | 2018-08-31 16:22:42 -0400 | [diff] [blame] | 382 | int i; |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 383 | |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 384 | lockdep_assert_held(&blkg->q->queue_lock); |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 385 | lockdep_assert_held(&blkcg->lock); |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 386 | |
| 387 | /* Something wrong if we are trying to remove same group twice */ |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 388 | WARN_ON_ONCE(list_empty(&blkg->q_node)); |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 389 | WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node)); |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 390 | |
Dennis Zhou (Facebook) | 6b06546 | 2018-08-31 16:22:42 -0400 | [diff] [blame] | 391 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
| 392 | struct blkcg_policy *pol = blkcg_policy[i]; |
| 393 | |
| 394 | if (blkg->pd[i] && pol->pd_offline_fn) |
| 395 | pol->pd_offline_fn(blkg->pd[i]); |
| 396 | } |
| 397 | |
Tejun Heo | f427d90 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 398 | blkg->online = false; |
| 399 | |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 400 | radix_tree_delete(&blkcg->blkg_tree, blkg->q->id); |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 401 | list_del_init(&blkg->q_node); |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 402 | hlist_del_init_rcu(&blkg->blkcg_node); |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 403 | |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 404 | /* |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 405 | * Both setting lookup hint to and clearing it from @blkg are done |
| 406 | * under queue_lock. If it's not pointing to @blkg now, it never |
| 407 | * will. Hint assignment itself can race safely. |
| 408 | */ |
Paul E. McKenney | ec6c676a | 2014-02-17 13:35:57 -0800 | [diff] [blame] | 409 | if (rcu_access_pointer(blkcg->blkg_hint) == blkg) |
Tejun Heo | a637120 | 2012-04-19 16:29:24 -0700 | [diff] [blame] | 410 | rcu_assign_pointer(blkcg->blkg_hint, NULL); |
| 411 | |
| 412 | /* |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 413 | * Put the reference taken at the time of creation so that when all |
| 414 | * queues are gone, group can be destroyed. |
| 415 | */ |
Dennis Zhou | 7fcf2b0 | 2018-12-05 12:10:38 -0500 | [diff] [blame] | 416 | percpu_ref_kill(&blkg->refcnt); |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 417 | } |
| 418 | |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 419 | /** |
| 420 | * blkg_destroy_all - destroy all blkgs associated with a request_queue |
| 421 | * @q: request_queue of interest |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 422 | * |
Tejun Heo | 3c96cb3 | 2012-04-13 13:11:34 -0700 | [diff] [blame] | 423 | * Destroy all blkgs associated with @q. |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 424 | */ |
Tejun Heo | 3c96cb3 | 2012-04-13 13:11:34 -0700 | [diff] [blame] | 425 | static void blkg_destroy_all(struct request_queue *q) |
Tejun Heo | 03aa264 | 2012-03-05 13:15:19 -0800 | [diff] [blame] | 426 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 427 | struct blkcg_gq *blkg, *n; |
Yu Kuai | a731763 | 2021-07-07 09:56:49 +0800 | [diff] [blame] | 428 | int count = BLKG_DESTROY_BATCH_SIZE; |
Tejun Heo | 72e06c2 | 2012-03-05 13:15:00 -0800 | [diff] [blame] | 429 | |
Yu Kuai | a731763 | 2021-07-07 09:56:49 +0800 | [diff] [blame] | 430 | restart: |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 431 | spin_lock_irq(&q->queue_lock); |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 432 | list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 433 | struct blkcg *blkcg = blkg->blkcg; |
Tejun Heo | 72e06c2 | 2012-03-05 13:15:00 -0800 | [diff] [blame] | 434 | |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 435 | spin_lock(&blkcg->lock); |
| 436 | blkg_destroy(blkg); |
| 437 | spin_unlock(&blkcg->lock); |
Yu Kuai | a731763 | 2021-07-07 09:56:49 +0800 | [diff] [blame] | 438 | |
| 439 | /* |
| 440 | * in order to avoid holding the spin lock for too long, release |
| 441 | * it when a batch of blkgs are destroyed. |
| 442 | */ |
| 443 | if (!(--count)) { |
| 444 | count = BLKG_DESTROY_BATCH_SIZE; |
| 445 | spin_unlock_irq(&q->queue_lock); |
| 446 | cond_resched(); |
| 447 | goto restart; |
| 448 | } |
Tejun Heo | 72e06c2 | 2012-03-05 13:15:00 -0800 | [diff] [blame] | 449 | } |
Tejun Heo | 6fe810b | 2015-09-05 15:47:36 -0400 | [diff] [blame] | 450 | |
| 451 | q->root_blkg = NULL; |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 452 | spin_unlock_irq(&q->queue_lock); |
Tejun Heo | 72e06c2 | 2012-03-05 13:15:00 -0800 | [diff] [blame] | 453 | } |
| 454 | |
Tejun Heo | 182446d | 2013-08-08 20:11:24 -0400 | [diff] [blame] | 455 | static int blkcg_reset_stats(struct cgroup_subsys_state *css, |
| 456 | struct cftype *cftype, u64 val) |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 457 | { |
Tejun Heo | 182446d | 2013-08-08 20:11:24 -0400 | [diff] [blame] | 458 | struct blkcg *blkcg = css_to_blkcg(css); |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 459 | struct blkcg_gq *blkg; |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 460 | int i, cpu; |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 461 | |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 462 | mutex_lock(&blkcg_pol_mutex); |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 463 | spin_lock_irq(&blkcg->lock); |
Tejun Heo | 997a026 | 2012-03-08 10:53:58 -0800 | [diff] [blame] | 464 | |
| 465 | /* |
| 466 | * Note that stat reset is racy - it doesn't synchronize against |
| 467 | * stat updates. This is a debug feature which shouldn't exist |
| 468 | * anyway. If you get hit by a race, retry. |
| 469 | */ |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 470 | hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 471 | for_each_possible_cpu(cpu) { |
| 472 | struct blkg_iostat_set *bis = |
| 473 | per_cpu_ptr(blkg->iostat_cpu, cpu); |
| 474 | memset(bis, 0, sizeof(*bis)); |
| 475 | } |
| 476 | memset(&blkg->iostat, 0, sizeof(blkg->iostat)); |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 477 | |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 478 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 479 | struct blkcg_policy *pol = blkcg_policy[i]; |
Tejun Heo | 549d3aa | 2012-03-05 13:15:16 -0800 | [diff] [blame] | 480 | |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 481 | if (blkg->pd[i] && pol->pd_reset_stats_fn) |
| 482 | pol->pd_reset_stats_fn(blkg->pd[i]); |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 483 | } |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 484 | } |
Vivek Goyal | f0bdc8c | 2011-05-19 15:38:30 -0400 | [diff] [blame] | 485 | |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 486 | spin_unlock_irq(&blkcg->lock); |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 487 | mutex_unlock(&blkcg_pol_mutex); |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 488 | return 0; |
| 489 | } |
| 490 | |
Tejun Heo | dd165eb | 2015-08-18 14:55:33 -0700 | [diff] [blame] | 491 | const char *blkg_dev_name(struct blkcg_gq *blkg) |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 492 | { |
Christoph Hellwig | d152c68 | 2021-08-16 15:46:24 +0200 | [diff] [blame] | 493 | if (!blkg->q->disk || !blkg->q->disk->bdi->dev) |
Christoph Hellwig | edb0872 | 2021-08-09 16:17:43 +0200 | [diff] [blame] | 494 | return NULL; |
Christoph Hellwig | d152c68 | 2021-08-16 15:46:24 +0200 | [diff] [blame] | 495 | return bdi_dev_name(blkg->q->disk->bdi); |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 496 | } |
| 497 | |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 498 | /** |
| 499 | * blkcg_print_blkgs - helper for printing per-blkg data |
| 500 | * @sf: seq_file to print to |
| 501 | * @blkcg: blkcg of interest |
| 502 | * @prfill: fill function to print out a blkg |
| 503 | * @pol: policy in question |
| 504 | * @data: data to be passed to @prfill |
| 505 | * @show_total: to print out sum of prfill return values or not |
| 506 | * |
| 507 | * This function invokes @prfill on each blkg of @blkcg if pd for the |
| 508 | * policy specified by @pol exists. @prfill is invoked with @sf, the |
Tejun Heo | 810ecfa | 2013-01-09 08:05:13 -0800 | [diff] [blame] | 509 | * policy data and @data and the matching queue lock held. If @show_total |
| 510 | * is %true, the sum of the return values from @prfill is printed with |
| 511 | * "Total" label at the end. |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 512 | * |
| 513 | * This is to be used to construct print functions for |
| 514 | * cftype->read_seq_string method. |
| 515 | */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 516 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 517 | u64 (*prfill)(struct seq_file *, |
| 518 | struct blkg_policy_data *, int), |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 519 | const struct blkcg_policy *pol, int data, |
Tejun Heo | ec39934 | 2012-04-13 13:11:27 -0700 | [diff] [blame] | 520 | bool show_total) |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 521 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 522 | struct blkcg_gq *blkg; |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 523 | u64 total = 0; |
| 524 | |
Tejun Heo | 810ecfa | 2013-01-09 08:05:13 -0800 | [diff] [blame] | 525 | rcu_read_lock(); |
Linus Torvalds | ee89f81 | 2013-02-28 12:52:24 -0800 | [diff] [blame] | 526 | hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 527 | spin_lock_irq(&blkg->q->queue_lock); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 528 | if (blkcg_policy_enabled(blkg->q, pol)) |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 529 | total += prfill(sf, blkg->pd[pol->plid], data); |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 530 | spin_unlock_irq(&blkg->q->queue_lock); |
Tejun Heo | 810ecfa | 2013-01-09 08:05:13 -0800 | [diff] [blame] | 531 | } |
| 532 | rcu_read_unlock(); |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 533 | |
| 534 | if (show_total) |
| 535 | seq_printf(sf, "Total %llu\n", (unsigned long long)total); |
| 536 | } |
Tejun Heo | 829fdb5 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 537 | EXPORT_SYMBOL_GPL(blkcg_print_blkgs); |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 538 | |
| 539 | /** |
| 540 | * __blkg_prfill_u64 - prfill helper for a single u64 value |
| 541 | * @sf: seq_file to print to |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 542 | * @pd: policy private data of interest |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 543 | * @v: value to print |
| 544 | * |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 545 | * Print @v to @sf for the device assocaited with @pd. |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 546 | */ |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 547 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v) |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 548 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 549 | const char *dname = blkg_dev_name(pd->blkg); |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 550 | |
| 551 | if (!dname) |
| 552 | return 0; |
| 553 | |
| 554 | seq_printf(sf, "%s %llu\n", dname, (unsigned long long)v); |
| 555 | return v; |
| 556 | } |
Tejun Heo | 829fdb5 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 557 | EXPORT_SYMBOL_GPL(__blkg_prfill_u64); |
Tejun Heo | d3d32e6 | 2012-04-01 14:38:42 -0700 | [diff] [blame] | 558 | |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 559 | /* Performs queue bypass and policy enabled checks then looks up blkg. */ |
| 560 | static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg, |
| 561 | const struct blkcg_policy *pol, |
| 562 | struct request_queue *q) |
| 563 | { |
| 564 | WARN_ON_ONCE(!rcu_read_lock_held()); |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 565 | lockdep_assert_held(&q->queue_lock); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 566 | |
| 567 | if (!blkcg_policy_enabled(q, pol)) |
| 568 | return ERR_PTR(-EOPNOTSUPP); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 569 | return __blkg_lookup(blkcg, q, true /* update_hint */); |
| 570 | } |
| 571 | |
Tejun Heo | 16b3de6 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 572 | /** |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 573 | * blkcg_conf_open_bdev - parse and open bdev for per-blkg config update |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 574 | * @inputp: input string pointer |
| 575 | * |
| 576 | * Parse the device node prefix part, MAJ:MIN, of per-blkg config update |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 577 | * from @input and get and return the matching bdev. *@inputp is |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 578 | * updated to point past the device node prefix. Returns an ERR_PTR() |
| 579 | * value on error. |
| 580 | * |
| 581 | * Use this function iff blkg_conf_prep() can't be used for some reason. |
| 582 | */ |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 583 | struct block_device *blkcg_conf_open_bdev(char **inputp) |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 584 | { |
| 585 | char *input = *inputp; |
| 586 | unsigned int major, minor; |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 587 | struct block_device *bdev; |
| 588 | int key_len; |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 589 | |
| 590 | if (sscanf(input, "%u:%u%n", &major, &minor, &key_len) != 2) |
| 591 | return ERR_PTR(-EINVAL); |
| 592 | |
| 593 | input += key_len; |
| 594 | if (!isspace(*input)) |
| 595 | return ERR_PTR(-EINVAL); |
| 596 | input = skip_spaces(input); |
| 597 | |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 598 | bdev = blkdev_get_no_open(MKDEV(major, minor)); |
| 599 | if (!bdev) |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 600 | return ERR_PTR(-ENODEV); |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 601 | if (bdev_is_partition(bdev)) { |
| 602 | blkdev_put_no_open(bdev); |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 603 | return ERR_PTR(-ENODEV); |
| 604 | } |
| 605 | |
| 606 | *inputp = input; |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 607 | return bdev; |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 608 | } |
| 609 | |
| 610 | /** |
| 611 | * blkg_conf_prep - parse and prepare for per-blkg config update |
Tejun Heo | 3a8b31d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 612 | * @blkcg: target block cgroup |
Tejun Heo | da8b066 | 2012-04-13 13:11:29 -0700 | [diff] [blame] | 613 | * @pol: target policy |
Tejun Heo | 3a8b31d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 614 | * @input: input string |
| 615 | * @ctx: blkg_conf_ctx to be filled |
| 616 | * |
| 617 | * Parse per-blkg config update from @input and initialize @ctx with the |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 618 | * result. @ctx->blkg points to the blkg to be updated and @ctx->body the |
| 619 | * part of @input following MAJ:MIN. This function returns with RCU read |
| 620 | * lock and queue lock held and must be paired with blkg_conf_finish(). |
Tejun Heo | 3a8b31d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 621 | */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 622 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 623 | char *input, struct blkg_conf_ctx *ctx) |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 624 | __acquires(rcu) __acquires(&bdev->bd_queue->queue_lock) |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 625 | { |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 626 | struct block_device *bdev; |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 627 | struct request_queue *q; |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 628 | struct blkcg_gq *blkg; |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 629 | int ret; |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 630 | |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 631 | bdev = blkcg_conf_open_bdev(&input); |
| 632 | if (IS_ERR(bdev)) |
| 633 | return PTR_ERR(bdev); |
Tejun Heo | e56da7e | 2012-03-05 13:15:07 -0800 | [diff] [blame] | 634 | |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 635 | q = bdev_get_queue(bdev); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 636 | |
Yu Kuai | 0c9d338 | 2021-10-20 09:40:36 +0800 | [diff] [blame] | 637 | /* |
| 638 | * blkcg_deactivate_policy() requires queue to be frozen, we can grab |
| 639 | * q_usage_counter to prevent concurrent with blkcg_deactivate_policy(). |
| 640 | */ |
| 641 | ret = blk_queue_enter(q, 0); |
| 642 | if (ret) |
Yu Kuai | 15c3010 | 2021-11-02 10:07:05 +0800 | [diff] [blame] | 643 | goto fail; |
Yu Kuai | 0c9d338 | 2021-10-20 09:40:36 +0800 | [diff] [blame] | 644 | |
Tejun Heo | e56da7e | 2012-03-05 13:15:07 -0800 | [diff] [blame] | 645 | rcu_read_lock(); |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 646 | spin_lock_irq(&q->queue_lock); |
Tejun Heo | da8b066 | 2012-04-13 13:11:29 -0700 | [diff] [blame] | 647 | |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 648 | blkg = blkg_lookup_check(blkcg, pol, q); |
Tejun Heo | 4bfd482 | 2012-03-05 13:15:08 -0800 | [diff] [blame] | 649 | if (IS_ERR(blkg)) { |
| 650 | ret = PTR_ERR(blkg); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 651 | goto fail_unlock; |
Vivek Goyal | 062a644 | 2010-09-15 17:06:33 -0400 | [diff] [blame] | 652 | } |
Tejun Heo | e56da7e | 2012-03-05 13:15:07 -0800 | [diff] [blame] | 653 | |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 654 | if (blkg) |
| 655 | goto success; |
| 656 | |
| 657 | /* |
| 658 | * Create blkgs walking down from blkcg_root to @blkcg, so that all |
| 659 | * non-root blkgs have access to their parents. |
| 660 | */ |
| 661 | while (true) { |
| 662 | struct blkcg *pos = blkcg; |
| 663 | struct blkcg *parent; |
| 664 | struct blkcg_gq *new_blkg; |
| 665 | |
| 666 | parent = blkcg_parent(blkcg); |
| 667 | while (parent && !__blkg_lookup(parent, q, false)) { |
| 668 | pos = parent; |
| 669 | parent = blkcg_parent(parent); |
| 670 | } |
| 671 | |
| 672 | /* Drop locks to do new blkg allocation with GFP_KERNEL. */ |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 673 | spin_unlock_irq(&q->queue_lock); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 674 | rcu_read_unlock(); |
| 675 | |
| 676 | new_blkg = blkg_alloc(pos, q, GFP_KERNEL); |
| 677 | if (unlikely(!new_blkg)) { |
| 678 | ret = -ENOMEM; |
Yu Kuai | 15c3010 | 2021-11-02 10:07:05 +0800 | [diff] [blame] | 679 | goto fail_exit_queue; |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 680 | } |
| 681 | |
Gabriel Krisman Bertazi | f255c19 | 2020-10-22 16:58:42 -0400 | [diff] [blame] | 682 | if (radix_tree_preload(GFP_KERNEL)) { |
| 683 | blkg_free(new_blkg); |
| 684 | ret = -ENOMEM; |
Yu Kuai | 15c3010 | 2021-11-02 10:07:05 +0800 | [diff] [blame] | 685 | goto fail_exit_queue; |
Gabriel Krisman Bertazi | f255c19 | 2020-10-22 16:58:42 -0400 | [diff] [blame] | 686 | } |
| 687 | |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 688 | rcu_read_lock(); |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 689 | spin_lock_irq(&q->queue_lock); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 690 | |
| 691 | blkg = blkg_lookup_check(pos, pol, q); |
| 692 | if (IS_ERR(blkg)) { |
| 693 | ret = PTR_ERR(blkg); |
Gabriel Krisman Bertazi | 52abfcb | 2020-10-22 16:58:41 -0400 | [diff] [blame] | 694 | blkg_free(new_blkg); |
Gabriel Krisman Bertazi | f255c19 | 2020-10-22 16:58:42 -0400 | [diff] [blame] | 695 | goto fail_preloaded; |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 696 | } |
| 697 | |
| 698 | if (blkg) { |
| 699 | blkg_free(new_blkg); |
| 700 | } else { |
| 701 | blkg = blkg_create(pos, q, new_blkg); |
Kefeng Wang | 98d669b | 2019-06-05 22:24:27 +0800 | [diff] [blame] | 702 | if (IS_ERR(blkg)) { |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 703 | ret = PTR_ERR(blkg); |
Gabriel Krisman Bertazi | f255c19 | 2020-10-22 16:58:42 -0400 | [diff] [blame] | 704 | goto fail_preloaded; |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 705 | } |
| 706 | } |
| 707 | |
Gabriel Krisman Bertazi | f255c19 | 2020-10-22 16:58:42 -0400 | [diff] [blame] | 708 | radix_tree_preload_end(); |
| 709 | |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 710 | if (pos == blkcg) |
| 711 | goto success; |
| 712 | } |
| 713 | success: |
Yu Kuai | 0c9d338 | 2021-10-20 09:40:36 +0800 | [diff] [blame] | 714 | blk_queue_exit(q); |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 715 | ctx->bdev = bdev; |
Tejun Heo | 3a8b31d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 716 | ctx->blkg = blkg; |
Tejun Heo | 015d254 | 2019-08-28 15:05:53 -0700 | [diff] [blame] | 717 | ctx->body = input; |
Tejun Heo | 726fa69 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 718 | return 0; |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 719 | |
Gabriel Krisman Bertazi | f255c19 | 2020-10-22 16:58:42 -0400 | [diff] [blame] | 720 | fail_preloaded: |
| 721 | radix_tree_preload_end(); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 722 | fail_unlock: |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 723 | spin_unlock_irq(&q->queue_lock); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 724 | rcu_read_unlock(); |
Yu Kuai | 15c3010 | 2021-11-02 10:07:05 +0800 | [diff] [blame] | 725 | fail_exit_queue: |
| 726 | blk_queue_exit(q); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 727 | fail: |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 728 | blkdev_put_no_open(bdev); |
Tahsin Erdogan | 457e490f | 2017-03-29 11:27:19 -0600 | [diff] [blame] | 729 | /* |
| 730 | * If queue was bypassing, we should retry. Do so after a |
| 731 | * short msleep(). It isn't strictly necessary but queue |
| 732 | * can be bypassing for some time and it's always nice to |
| 733 | * avoid busy looping. |
| 734 | */ |
| 735 | if (ret == -EBUSY) { |
| 736 | msleep(10); |
| 737 | ret = restart_syscall(); |
| 738 | } |
| 739 | return ret; |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 740 | } |
Pavel Begunkov | 89f3b6d | 2019-09-14 20:31:50 +0300 | [diff] [blame] | 741 | EXPORT_SYMBOL_GPL(blkg_conf_prep); |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 742 | |
Tejun Heo | 3a8b31d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 743 | /** |
| 744 | * blkg_conf_finish - finish up per-blkg config update |
| 745 | * @ctx: blkg_conf_ctx intiailized by blkg_conf_prep() |
| 746 | * |
| 747 | * Finish up after per-blkg config update. This function must be paired |
| 748 | * with blkg_conf_prep(). |
| 749 | */ |
Tejun Heo | 829fdb5 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 750 | void blkg_conf_finish(struct blkg_conf_ctx *ctx) |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 751 | __releases(&ctx->bdev->bd_queue->queue_lock) __releases(rcu) |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 752 | { |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 753 | spin_unlock_irq(&bdev_get_queue(ctx->bdev)->queue_lock); |
Tejun Heo | 3a8b31d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 754 | rcu_read_unlock(); |
Christoph Hellwig | 22ae8ce | 2020-11-26 09:23:26 +0100 | [diff] [blame] | 755 | blkdev_put_no_open(ctx->bdev); |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 756 | } |
Pavel Begunkov | 89f3b6d | 2019-09-14 20:31:50 +0300 | [diff] [blame] | 757 | EXPORT_SYMBOL_GPL(blkg_conf_finish); |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 758 | |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 759 | static void blkg_iostat_set(struct blkg_iostat *dst, struct blkg_iostat *src) |
| 760 | { |
| 761 | int i; |
| 762 | |
| 763 | for (i = 0; i < BLKG_IOSTAT_NR; i++) { |
| 764 | dst->bytes[i] = src->bytes[i]; |
| 765 | dst->ios[i] = src->ios[i]; |
| 766 | } |
| 767 | } |
| 768 | |
| 769 | static void blkg_iostat_add(struct blkg_iostat *dst, struct blkg_iostat *src) |
| 770 | { |
| 771 | int i; |
| 772 | |
| 773 | for (i = 0; i < BLKG_IOSTAT_NR; i++) { |
| 774 | dst->bytes[i] += src->bytes[i]; |
| 775 | dst->ios[i] += src->ios[i]; |
| 776 | } |
| 777 | } |
| 778 | |
| 779 | static void blkg_iostat_sub(struct blkg_iostat *dst, struct blkg_iostat *src) |
| 780 | { |
| 781 | int i; |
| 782 | |
| 783 | for (i = 0; i < BLKG_IOSTAT_NR; i++) { |
| 784 | dst->bytes[i] -= src->bytes[i]; |
| 785 | dst->ios[i] -= src->ios[i]; |
| 786 | } |
| 787 | } |
| 788 | |
| 789 | static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu) |
| 790 | { |
| 791 | struct blkcg *blkcg = css_to_blkcg(css); |
| 792 | struct blkcg_gq *blkg; |
| 793 | |
Johannes Weiner | dc26532 | 2021-04-29 22:56:23 -0700 | [diff] [blame] | 794 | /* Root-level stats are sourced from system-wide IO stats */ |
| 795 | if (!cgroup_parent(css->cgroup)) |
| 796 | return; |
| 797 | |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 798 | rcu_read_lock(); |
| 799 | |
| 800 | hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { |
| 801 | struct blkcg_gq *parent = blkg->parent; |
| 802 | struct blkg_iostat_set *bisc = per_cpu_ptr(blkg->iostat_cpu, cpu); |
| 803 | struct blkg_iostat cur, delta; |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 804 | unsigned long flags; |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 805 | unsigned int seq; |
| 806 | |
| 807 | /* fetch the current per-cpu values */ |
| 808 | do { |
| 809 | seq = u64_stats_fetch_begin(&bisc->sync); |
| 810 | blkg_iostat_set(&cur, &bisc->cur); |
| 811 | } while (u64_stats_fetch_retry(&bisc->sync, seq)); |
| 812 | |
| 813 | /* propagate percpu delta to global */ |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 814 | flags = u64_stats_update_begin_irqsave(&blkg->iostat.sync); |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 815 | blkg_iostat_set(&delta, &cur); |
| 816 | blkg_iostat_sub(&delta, &bisc->last); |
| 817 | blkg_iostat_add(&blkg->iostat.cur, &delta); |
| 818 | blkg_iostat_add(&bisc->last, &delta); |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 819 | u64_stats_update_end_irqrestore(&blkg->iostat.sync, flags); |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 820 | |
Johannes Weiner | dc26532 | 2021-04-29 22:56:23 -0700 | [diff] [blame] | 821 | /* propagate global delta to parent (unless that's root) */ |
| 822 | if (parent && parent->parent) { |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 823 | flags = u64_stats_update_begin_irqsave(&parent->iostat.sync); |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 824 | blkg_iostat_set(&delta, &blkg->iostat.cur); |
| 825 | blkg_iostat_sub(&delta, &blkg->iostat.last); |
| 826 | blkg_iostat_add(&parent->iostat.cur, &delta); |
| 827 | blkg_iostat_add(&blkg->iostat.last, &delta); |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 828 | u64_stats_update_end_irqrestore(&parent->iostat.sync, flags); |
Boris Burkov | cd1fc4b | 2020-06-01 13:11:43 -0700 | [diff] [blame] | 829 | } |
| 830 | } |
| 831 | |
| 832 | rcu_read_unlock(); |
| 833 | } |
| 834 | |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 835 | /* |
Johannes Weiner | dc26532 | 2021-04-29 22:56:23 -0700 | [diff] [blame] | 836 | * We source root cgroup stats from the system-wide stats to avoid |
| 837 | * tracking the same information twice and incurring overhead when no |
| 838 | * cgroups are defined. For that reason, cgroup_rstat_flush in |
| 839 | * blkcg_print_stat does not actually fill out the iostat in the root |
| 840 | * cgroup's blkcg_gq. |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 841 | * |
| 842 | * However, we would like to re-use the printing code between the root and |
| 843 | * non-root cgroups to the extent possible. For that reason, we simulate |
| 844 | * flushing the root cgroup's stats by explicitly filling in the iostat |
| 845 | * with disk level statistics. |
| 846 | */ |
| 847 | static void blkcg_fill_root_iostats(void) |
| 848 | { |
| 849 | struct class_dev_iter iter; |
| 850 | struct device *dev; |
| 851 | |
| 852 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); |
| 853 | while ((dev = class_dev_iter_next(&iter))) { |
Christoph Hellwig | 0d02129 | 2020-11-27 16:43:51 +0100 | [diff] [blame] | 854 | struct block_device *bdev = dev_to_bdev(dev); |
| 855 | struct blkcg_gq *blkg = |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 856 | blk_queue_root_blkg(bdev_get_queue(bdev)); |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 857 | struct blkg_iostat tmp; |
| 858 | int cpu; |
| 859 | |
| 860 | memset(&tmp, 0, sizeof(tmp)); |
| 861 | for_each_possible_cpu(cpu) { |
| 862 | struct disk_stats *cpu_dkstats; |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 863 | unsigned long flags; |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 864 | |
Christoph Hellwig | 0d02129 | 2020-11-27 16:43:51 +0100 | [diff] [blame] | 865 | cpu_dkstats = per_cpu_ptr(bdev->bd_stats, cpu); |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 866 | tmp.ios[BLKG_IOSTAT_READ] += |
| 867 | cpu_dkstats->ios[STAT_READ]; |
| 868 | tmp.ios[BLKG_IOSTAT_WRITE] += |
| 869 | cpu_dkstats->ios[STAT_WRITE]; |
| 870 | tmp.ios[BLKG_IOSTAT_DISCARD] += |
| 871 | cpu_dkstats->ios[STAT_DISCARD]; |
| 872 | // convert sectors to bytes |
| 873 | tmp.bytes[BLKG_IOSTAT_READ] += |
| 874 | cpu_dkstats->sectors[STAT_READ] << 9; |
| 875 | tmp.bytes[BLKG_IOSTAT_WRITE] += |
| 876 | cpu_dkstats->sectors[STAT_WRITE] << 9; |
| 877 | tmp.bytes[BLKG_IOSTAT_DISCARD] += |
| 878 | cpu_dkstats->sectors[STAT_DISCARD] << 9; |
| 879 | |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 880 | flags = u64_stats_update_begin_irqsave(&blkg->iostat.sync); |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 881 | blkg_iostat_set(&blkg->iostat.cur, &tmp); |
Tejun Heo | c3df5fb | 2021-07-27 13:12:20 -1000 | [diff] [blame] | 882 | u64_stats_update_end_irqrestore(&blkg->iostat.sync, flags); |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 883 | } |
| 884 | } |
| 885 | } |
| 886 | |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 887 | static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s) |
| 888 | { |
| 889 | struct blkg_iostat_set *bis = &blkg->iostat; |
| 890 | u64 rbytes, wbytes, rios, wios, dbytes, dios; |
| 891 | bool has_stats = false; |
| 892 | const char *dname; |
| 893 | unsigned seq; |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 894 | int i; |
| 895 | |
| 896 | if (!blkg->online) |
| 897 | return; |
| 898 | |
| 899 | dname = blkg_dev_name(blkg); |
| 900 | if (!dname) |
| 901 | return; |
| 902 | |
Christoph Hellwig | 252c651 | 2021-08-10 17:26:23 +0200 | [diff] [blame] | 903 | seq_printf(s, "%s ", dname); |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 904 | |
| 905 | do { |
| 906 | seq = u64_stats_fetch_begin(&bis->sync); |
| 907 | |
| 908 | rbytes = bis->cur.bytes[BLKG_IOSTAT_READ]; |
| 909 | wbytes = bis->cur.bytes[BLKG_IOSTAT_WRITE]; |
| 910 | dbytes = bis->cur.bytes[BLKG_IOSTAT_DISCARD]; |
| 911 | rios = bis->cur.ios[BLKG_IOSTAT_READ]; |
| 912 | wios = bis->cur.ios[BLKG_IOSTAT_WRITE]; |
| 913 | dios = bis->cur.ios[BLKG_IOSTAT_DISCARD]; |
| 914 | } while (u64_stats_fetch_retry(&bis->sync, seq)); |
| 915 | |
| 916 | if (rbytes || wbytes || rios || wios) { |
| 917 | has_stats = true; |
Christoph Hellwig | 252c651 | 2021-08-10 17:26:23 +0200 | [diff] [blame] | 918 | seq_printf(s, "rbytes=%llu wbytes=%llu rios=%llu wios=%llu dbytes=%llu dios=%llu", |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 919 | rbytes, wbytes, rios, wios, |
| 920 | dbytes, dios); |
| 921 | } |
| 922 | |
| 923 | if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) { |
| 924 | has_stats = true; |
Christoph Hellwig | 252c651 | 2021-08-10 17:26:23 +0200 | [diff] [blame] | 925 | seq_printf(s, " use_delay=%d delay_nsec=%llu", |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 926 | atomic_read(&blkg->use_delay), |
| 927 | atomic64_read(&blkg->delay_nsec)); |
| 928 | } |
| 929 | |
| 930 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
| 931 | struct blkcg_policy *pol = blkcg_policy[i]; |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 932 | |
| 933 | if (!blkg->pd[i] || !pol->pd_stat_fn) |
| 934 | continue; |
| 935 | |
Christoph Hellwig | 252c651 | 2021-08-10 17:26:23 +0200 | [diff] [blame] | 936 | if (pol->pd_stat_fn(blkg->pd[i], s)) |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 937 | has_stats = true; |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 938 | } |
| 939 | |
Christoph Hellwig | 252c651 | 2021-08-10 17:26:23 +0200 | [diff] [blame] | 940 | if (has_stats) |
| 941 | seq_printf(s, "\n"); |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 942 | } |
| 943 | |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 944 | static int blkcg_print_stat(struct seq_file *sf, void *v) |
| 945 | { |
| 946 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
| 947 | struct blkcg_gq *blkg; |
| 948 | |
Boris Burkov | ef45fe4 | 2020-06-01 13:12:05 -0700 | [diff] [blame] | 949 | if (!seq_css(sf)->parent) |
| 950 | blkcg_fill_root_iostats(); |
| 951 | else |
| 952 | cgroup_rstat_flush(blkcg->css.cgroup); |
| 953 | |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 954 | rcu_read_lock(); |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 955 | hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { |
Tejun Heo | b081436 | 2019-11-05 08:09:51 -0800 | [diff] [blame] | 956 | spin_lock_irq(&blkg->q->queue_lock); |
Christoph Hellwig | 49cb516 | 2021-08-10 17:26:22 +0200 | [diff] [blame] | 957 | blkcg_print_one_stat(blkg, sf); |
Tejun Heo | b081436 | 2019-11-05 08:09:51 -0800 | [diff] [blame] | 958 | spin_unlock_irq(&blkg->q->queue_lock); |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 959 | } |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 960 | rcu_read_unlock(); |
| 961 | return 0; |
| 962 | } |
| 963 | |
Bart Van Assche | e1f3b94 | 2016-06-14 17:04:32 +0200 | [diff] [blame] | 964 | static struct cftype blkcg_files[] = { |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 965 | { |
| 966 | .name = "stat", |
| 967 | .seq_show = blkcg_print_stat, |
| 968 | }, |
| 969 | { } /* terminate */ |
| 970 | }; |
| 971 | |
Bart Van Assche | e1f3b94 | 2016-06-14 17:04:32 +0200 | [diff] [blame] | 972 | static struct cftype blkcg_legacy_files[] = { |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 973 | { |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 974 | .name = "reset_stats", |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 975 | .write_u64 = blkcg_reset_stats, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 976 | }, |
Tejun Heo | 4baf6e3 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 977 | { } /* terminate */ |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 978 | }; |
| 979 | |
Dennis Zhou (Facebook) | 59b5771 | 2018-08-31 16:22:43 -0400 | [diff] [blame] | 980 | /* |
| 981 | * blkcg destruction is a three-stage process. |
| 982 | * |
| 983 | * 1. Destruction starts. The blkcg_css_offline() callback is invoked |
| 984 | * which offlines writeback. Here we tie the next stage of blkg destruction |
| 985 | * to the completion of writeback associated with the blkcg. This lets us |
| 986 | * avoid punting potentially large amounts of outstanding writeback to root |
| 987 | * while maintaining any ongoing policies. The next stage is triggered when |
| 988 | * the nr_cgwbs count goes to zero. |
| 989 | * |
| 990 | * 2. When the nr_cgwbs count goes to zero, blkcg_destroy_blkgs() is called |
| 991 | * and handles the destruction of blkgs. Here the css reference held by |
| 992 | * the blkg is put back eventually allowing blkcg_css_free() to be called. |
| 993 | * This work may occur in cgwb_release_workfn() on the cgwb_release |
| 994 | * workqueue. Any submitted ios that fail to get the blkg ref will be |
| 995 | * punted to the root_blkg. |
| 996 | * |
| 997 | * 3. Once the blkcg ref count goes to zero, blkcg_css_free() is called. |
| 998 | * This finally frees the blkcg. |
| 999 | */ |
| 1000 | |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1001 | /** |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 1002 | * blkcg_css_offline - cgroup css_offline callback |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1003 | * @css: css of interest |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1004 | * |
Dennis Zhou (Facebook) | 59b5771 | 2018-08-31 16:22:43 -0400 | [diff] [blame] | 1005 | * This function is called when @css is about to go away. Here the cgwbs are |
| 1006 | * offlined first and only once writeback associated with the blkcg has |
| 1007 | * finished do we start step 2 (see above). |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1008 | */ |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1009 | static void blkcg_css_offline(struct cgroup_subsys_state *css) |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1010 | { |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1011 | struct blkcg *blkcg = css_to_blkcg(css); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1012 | |
Dennis Zhou (Facebook) | 59b5771 | 2018-08-31 16:22:43 -0400 | [diff] [blame] | 1013 | /* this prevents anyone from attaching or migrating to this blkcg */ |
| 1014 | wb_blkcg_offline(blkcg); |
| 1015 | |
Tejun Heo | d866dbf | 2019-07-24 10:37:22 -0700 | [diff] [blame] | 1016 | /* put the base online pin allowing step 2 to be triggered */ |
| 1017 | blkcg_unpin_online(blkcg); |
Dennis Zhou (Facebook) | 59b5771 | 2018-08-31 16:22:43 -0400 | [diff] [blame] | 1018 | } |
| 1019 | |
| 1020 | /** |
| 1021 | * blkcg_destroy_blkgs - responsible for shooting down blkgs |
| 1022 | * @blkcg: blkcg of interest |
| 1023 | * |
| 1024 | * blkgs should be removed while holding both q and blkcg locks. As blkcg lock |
| 1025 | * is nested inside q lock, this function performs reverse double lock dancing. |
| 1026 | * Destroying the blkgs releases the reference held on the blkcg's css allowing |
| 1027 | * blkcg_css_free to eventually be called. |
| 1028 | * |
| 1029 | * This is the blkcg counterpart of ioc_release_fn(). |
| 1030 | */ |
| 1031 | void blkcg_destroy_blkgs(struct blkcg *blkcg) |
| 1032 | { |
Baolin Wang | 6c635ca | 2021-01-28 13:58:15 +0800 | [diff] [blame] | 1033 | might_sleep(); |
| 1034 | |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1035 | spin_lock_irq(&blkcg->lock); |
Tejun Heo | 7ee9c56 | 2012-03-05 13:15:11 -0800 | [diff] [blame] | 1036 | |
Dennis Zhou (Facebook) | 6b06546 | 2018-08-31 16:22:42 -0400 | [diff] [blame] | 1037 | while (!hlist_empty(&blkcg->blkg_list)) { |
| 1038 | struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first, |
| 1039 | struct blkcg_gq, blkcg_node); |
Tejun Heo | c875f4d | 2012-03-05 13:15:22 -0800 | [diff] [blame] | 1040 | struct request_queue *q = blkg->q; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1041 | |
Baolin Wang | 6c635ca | 2021-01-28 13:58:15 +0800 | [diff] [blame] | 1042 | if (need_resched() || !spin_trylock(&q->queue_lock)) { |
| 1043 | /* |
| 1044 | * Given that the system can accumulate a huge number |
| 1045 | * of blkgs in pathological cases, check to see if we |
| 1046 | * need to rescheduling to avoid softlockup. |
| 1047 | */ |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1048 | spin_unlock_irq(&blkcg->lock); |
Baolin Wang | 6c635ca | 2021-01-28 13:58:15 +0800 | [diff] [blame] | 1049 | cond_resched(); |
Dan Carpenter | a556793 | 2012-03-29 20:57:08 +0200 | [diff] [blame] | 1050 | spin_lock_irq(&blkcg->lock); |
Baolin Wang | 6c635ca | 2021-01-28 13:58:15 +0800 | [diff] [blame] | 1051 | continue; |
Jens Axboe | 0f3942a | 2010-05-03 14:28:55 +0200 | [diff] [blame] | 1052 | } |
Baolin Wang | 6c635ca | 2021-01-28 13:58:15 +0800 | [diff] [blame] | 1053 | |
| 1054 | blkg_destroy(blkg); |
| 1055 | spin_unlock(&q->queue_lock); |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1056 | } |
Jens Axboe | 0f3942a | 2010-05-03 14:28:55 +0200 | [diff] [blame] | 1057 | |
Tejun Heo | 9f13ef6 | 2012-03-05 13:15:21 -0800 | [diff] [blame] | 1058 | spin_unlock_irq(&blkcg->lock); |
Tejun Heo | 7ee9c56 | 2012-03-05 13:15:11 -0800 | [diff] [blame] | 1059 | } |
| 1060 | |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1061 | static void blkcg_css_free(struct cgroup_subsys_state *css) |
Tejun Heo | 7ee9c56 | 2012-03-05 13:15:11 -0800 | [diff] [blame] | 1062 | { |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1063 | struct blkcg *blkcg = css_to_blkcg(css); |
Tejun Heo | bc915e6 | 2015-08-18 14:55:08 -0700 | [diff] [blame] | 1064 | int i; |
Tejun Heo | 7ee9c56 | 2012-03-05 13:15:11 -0800 | [diff] [blame] | 1065 | |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 1066 | mutex_lock(&blkcg_pol_mutex); |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1067 | |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 1068 | list_del(&blkcg->all_blkcgs_node); |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 1069 | |
Tejun Heo | bc915e6 | 2015-08-18 14:55:08 -0700 | [diff] [blame] | 1070 | for (i = 0; i < BLKCG_MAX_POLS; i++) |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1071 | if (blkcg->cpd[i]) |
| 1072 | blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]); |
| 1073 | |
| 1074 | mutex_unlock(&blkcg_pol_mutex); |
| 1075 | |
Tejun Heo | bc915e6 | 2015-08-18 14:55:08 -0700 | [diff] [blame] | 1076 | kfree(blkcg); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1077 | } |
| 1078 | |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1079 | static struct cgroup_subsys_state * |
| 1080 | blkcg_css_alloc(struct cgroup_subsys_state *parent_css) |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1081 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1082 | struct blkcg *blkcg; |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1083 | struct cgroup_subsys_state *ret; |
| 1084 | int i; |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1085 | |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 1086 | mutex_lock(&blkcg_pol_mutex); |
| 1087 | |
Tejun Heo | eb95419 | 2013-08-08 20:11:23 -0400 | [diff] [blame] | 1088 | if (!parent_css) { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1089 | blkcg = &blkcg_root; |
Tejun Heo | bc915e6 | 2015-08-18 14:55:08 -0700 | [diff] [blame] | 1090 | } else { |
| 1091 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); |
| 1092 | if (!blkcg) { |
| 1093 | ret = ERR_PTR(-ENOMEM); |
weiping zhang | 4c18c9e | 2017-08-25 23:49:32 +0800 | [diff] [blame] | 1094 | goto unlock; |
Tejun Heo | bc915e6 | 2015-08-18 14:55:08 -0700 | [diff] [blame] | 1095 | } |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1096 | } |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1097 | |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1098 | for (i = 0; i < BLKCG_MAX_POLS ; i++) { |
| 1099 | struct blkcg_policy *pol = blkcg_policy[i]; |
| 1100 | struct blkcg_policy_data *cpd; |
| 1101 | |
| 1102 | /* |
| 1103 | * If the policy hasn't been attached yet, wait for it |
| 1104 | * to be attached before doing anything else. Otherwise, |
| 1105 | * check if the policy requires any specific per-cgroup |
| 1106 | * data: if it does, allocate and initialize it. |
| 1107 | */ |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1108 | if (!pol || !pol->cpd_alloc_fn) |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1109 | continue; |
| 1110 | |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1111 | cpd = pol->cpd_alloc_fn(GFP_KERNEL); |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1112 | if (!cpd) { |
| 1113 | ret = ERR_PTR(-ENOMEM); |
| 1114 | goto free_pd_blkcg; |
| 1115 | } |
Tejun Heo | 8143764 | 2015-08-18 14:55:15 -0700 | [diff] [blame] | 1116 | blkcg->cpd[i] = cpd; |
| 1117 | cpd->blkcg = blkcg; |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1118 | cpd->plid = i; |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1119 | if (pol->cpd_init_fn) |
| 1120 | pol->cpd_init_fn(cpd); |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1121 | } |
| 1122 | |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1123 | spin_lock_init(&blkcg->lock); |
Tejun Heo | d866dbf | 2019-07-24 10:37:22 -0700 | [diff] [blame] | 1124 | refcount_set(&blkcg->online_pin, 1); |
Tejun Heo | e00f4f4 | 2016-11-21 18:03:32 -0500 | [diff] [blame] | 1125 | INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT | __GFP_NOWARN); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1126 | INIT_HLIST_HEAD(&blkcg->blkg_list); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 1127 | #ifdef CONFIG_CGROUP_WRITEBACK |
| 1128 | INIT_LIST_HEAD(&blkcg->cgwb_list); |
| 1129 | #endif |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 1130 | list_add_tail(&blkcg->all_blkcgs_node, &all_blkcgs); |
| 1131 | |
| 1132 | mutex_unlock(&blkcg_pol_mutex); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1133 | return &blkcg->css; |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1134 | |
| 1135 | free_pd_blkcg: |
| 1136 | for (i--; i >= 0; i--) |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1137 | if (blkcg->cpd[i]) |
| 1138 | blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]); |
weiping zhang | 4c18c9e | 2017-08-25 23:49:32 +0800 | [diff] [blame] | 1139 | |
| 1140 | if (blkcg != &blkcg_root) |
| 1141 | kfree(blkcg); |
| 1142 | unlock: |
Tejun Heo | 7876f93 | 2015-07-09 16:39:49 -0400 | [diff] [blame] | 1143 | mutex_unlock(&blkcg_pol_mutex); |
Arianna Avanzini | e48453c | 2015-06-05 23:38:42 +0200 | [diff] [blame] | 1144 | return ret; |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1145 | } |
| 1146 | |
Tejun Heo | 4308a43 | 2019-07-24 10:37:55 -0700 | [diff] [blame] | 1147 | static int blkcg_css_online(struct cgroup_subsys_state *css) |
| 1148 | { |
| 1149 | struct blkcg *blkcg = css_to_blkcg(css); |
| 1150 | struct blkcg *parent = blkcg_parent(blkcg); |
| 1151 | |
| 1152 | /* |
| 1153 | * blkcg_pin_online() is used to delay blkcg offline so that blkgs |
| 1154 | * don't go offline while cgwbs are still active on them. Pin the |
| 1155 | * parent so that offline always happens towards the root. |
| 1156 | */ |
| 1157 | if (parent) |
| 1158 | blkcg_pin_online(parent); |
| 1159 | return 0; |
| 1160 | } |
| 1161 | |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1162 | /** |
| 1163 | * blkcg_init_queue - initialize blkcg part of request queue |
| 1164 | * @q: request_queue to initialize |
| 1165 | * |
Christoph Hellwig | c62b37d | 2020-07-01 10:59:43 +0200 | [diff] [blame] | 1166 | * Called from blk_alloc_queue(). Responsible for initializing blkcg |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1167 | * part of new request_queue @q. |
| 1168 | * |
| 1169 | * RETURNS: |
| 1170 | * 0 on success, -errno on failure. |
| 1171 | */ |
| 1172 | int blkcg_init_queue(struct request_queue *q) |
| 1173 | { |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 1174 | struct blkcg_gq *new_blkg, *blkg; |
| 1175 | bool preloaded; |
Tejun Heo | ec13b1d | 2015-05-22 17:13:19 -0400 | [diff] [blame] | 1176 | int ret; |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1177 | |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 1178 | new_blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL); |
| 1179 | if (!new_blkg) |
| 1180 | return -ENOMEM; |
| 1181 | |
| 1182 | preloaded = !radix_tree_preload(GFP_KERNEL); |
| 1183 | |
Jiang Biao | bea5488 | 2018-04-19 12:04:26 +0800 | [diff] [blame] | 1184 | /* Make sure the root blkg exists. */ |
Tejun Heo | ec13b1d | 2015-05-22 17:13:19 -0400 | [diff] [blame] | 1185 | rcu_read_lock(); |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1186 | spin_lock_irq(&q->queue_lock); |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 1187 | blkg = blkg_create(&blkcg_root, q, new_blkg); |
Jiang Biao | 901932a | 2018-04-19 12:06:09 +0800 | [diff] [blame] | 1188 | if (IS_ERR(blkg)) |
| 1189 | goto err_unlock; |
| 1190 | q->root_blkg = blkg; |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1191 | spin_unlock_irq(&q->queue_lock); |
Tejun Heo | ec13b1d | 2015-05-22 17:13:19 -0400 | [diff] [blame] | 1192 | rcu_read_unlock(); |
| 1193 | |
Jens Axboe | d708f0d | 2017-03-29 11:25:48 -0600 | [diff] [blame] | 1194 | if (preloaded) |
| 1195 | radix_tree_preload_end(); |
| 1196 | |
Bart Van Assche | 556910e | 2021-06-17 17:44:44 -0700 | [diff] [blame] | 1197 | ret = blk_ioprio_init(q); |
| 1198 | if (ret) |
| 1199 | goto err_destroy_all; |
| 1200 | |
Tejun Heo | ec13b1d | 2015-05-22 17:13:19 -0400 | [diff] [blame] | 1201 | ret = blk_throtl_init(q); |
Christoph Hellwig | 04be60b | 2018-11-14 17:02:12 +0100 | [diff] [blame] | 1202 | if (ret) |
| 1203 | goto err_destroy_all; |
Yufen Yu | 27029b4 | 2020-08-10 22:21:16 -0400 | [diff] [blame] | 1204 | |
Yanfei Xu | 6f5ddde | 2021-09-15 15:24:26 +0800 | [diff] [blame] | 1205 | ret = blk_iolatency_init(q); |
| 1206 | if (ret) { |
| 1207 | blk_throtl_exit(q); |
| 1208 | goto err_destroy_all; |
| 1209 | } |
| 1210 | |
Christoph Hellwig | 04be60b | 2018-11-14 17:02:12 +0100 | [diff] [blame] | 1211 | return 0; |
Jiang Biao | 901932a | 2018-04-19 12:06:09 +0800 | [diff] [blame] | 1212 | |
Christoph Hellwig | 04be60b | 2018-11-14 17:02:12 +0100 | [diff] [blame] | 1213 | err_destroy_all: |
Christoph Hellwig | 04be60b | 2018-11-14 17:02:12 +0100 | [diff] [blame] | 1214 | blkg_destroy_all(q); |
Christoph Hellwig | 04be60b | 2018-11-14 17:02:12 +0100 | [diff] [blame] | 1215 | return ret; |
Jiang Biao | 901932a | 2018-04-19 12:06:09 +0800 | [diff] [blame] | 1216 | err_unlock: |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1217 | spin_unlock_irq(&q->queue_lock); |
Jiang Biao | 901932a | 2018-04-19 12:06:09 +0800 | [diff] [blame] | 1218 | rcu_read_unlock(); |
| 1219 | if (preloaded) |
| 1220 | radix_tree_preload_end(); |
| 1221 | return PTR_ERR(blkg); |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1222 | } |
| 1223 | |
| 1224 | /** |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1225 | * blkcg_exit_queue - exit and release blkcg part of request_queue |
| 1226 | * @q: request_queue being released |
| 1227 | * |
Marcos Paulo de Souza | 7585d50 | 2019-01-25 00:01:42 -0200 | [diff] [blame] | 1228 | * Called from blk_exit_queue(). Responsible for exiting blkcg part. |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1229 | */ |
| 1230 | void blkcg_exit_queue(struct request_queue *q) |
| 1231 | { |
Tejun Heo | 3c96cb3 | 2012-04-13 13:11:34 -0700 | [diff] [blame] | 1232 | blkg_destroy_all(q); |
Tejun Heo | 5efd611 | 2012-03-05 13:15:12 -0800 | [diff] [blame] | 1233 | blk_throtl_exit(q); |
| 1234 | } |
| 1235 | |
Tejun Heo | 69d7fde | 2015-08-18 14:55:36 -0700 | [diff] [blame] | 1236 | static void blkcg_bind(struct cgroup_subsys_state *root_css) |
| 1237 | { |
| 1238 | int i; |
| 1239 | |
| 1240 | mutex_lock(&blkcg_pol_mutex); |
| 1241 | |
| 1242 | for (i = 0; i < BLKCG_MAX_POLS; i++) { |
| 1243 | struct blkcg_policy *pol = blkcg_policy[i]; |
| 1244 | struct blkcg *blkcg; |
| 1245 | |
| 1246 | if (!pol || !pol->cpd_bind_fn) |
| 1247 | continue; |
| 1248 | |
| 1249 | list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) |
| 1250 | if (blkcg->cpd[pol->plid]) |
| 1251 | pol->cpd_bind_fn(blkcg->cpd[pol->plid]); |
| 1252 | } |
| 1253 | mutex_unlock(&blkcg_pol_mutex); |
| 1254 | } |
| 1255 | |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1256 | static void blkcg_exit(struct task_struct *tsk) |
| 1257 | { |
| 1258 | if (tsk->throttle_queue) |
| 1259 | blk_put_queue(tsk->throttle_queue); |
| 1260 | tsk->throttle_queue = NULL; |
| 1261 | } |
| 1262 | |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 1263 | struct cgroup_subsys io_cgrp_subsys = { |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 1264 | .css_alloc = blkcg_css_alloc, |
Tejun Heo | 4308a43 | 2019-07-24 10:37:55 -0700 | [diff] [blame] | 1265 | .css_online = blkcg_css_online, |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 1266 | .css_offline = blkcg_css_offline, |
| 1267 | .css_free = blkcg_css_free, |
Tejun Heo | f733164 | 2019-11-07 11:18:03 -0800 | [diff] [blame] | 1268 | .css_rstat_flush = blkcg_rstat_flush, |
Tejun Heo | 69d7fde | 2015-08-18 14:55:36 -0700 | [diff] [blame] | 1269 | .bind = blkcg_bind, |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1270 | .dfl_cftypes = blkcg_files, |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1271 | .legacy_cftypes = blkcg_legacy_files, |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 1272 | .legacy_name = "blkio", |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1273 | .exit = blkcg_exit, |
Tejun Heo | 1ced953 | 2014-07-08 18:02:57 -0400 | [diff] [blame] | 1274 | #ifdef CONFIG_MEMCG |
| 1275 | /* |
| 1276 | * This ensures that, if available, memcg is automatically enabled |
| 1277 | * together on the default hierarchy so that the owner cgroup can |
| 1278 | * be retrieved from writeback pages. |
| 1279 | */ |
| 1280 | .depends_on = 1 << memory_cgrp_id, |
| 1281 | #endif |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 1282 | }; |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 1283 | EXPORT_SYMBOL_GPL(io_cgrp_subsys); |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 1284 | |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1285 | /** |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1286 | * blkcg_activate_policy - activate a blkcg policy on a request_queue |
| 1287 | * @q: request_queue of interest |
| 1288 | * @pol: blkcg policy to activate |
| 1289 | * |
| 1290 | * Activate @pol on @q. Requires %GFP_KERNEL context. @q goes through |
| 1291 | * bypass mode to populate its blkgs with policy_data for @pol. |
| 1292 | * |
| 1293 | * Activation happens with @q bypassed, so nobody would be accessing blkgs |
| 1294 | * from IO path. Update of each blkg is protected by both queue and blkcg |
| 1295 | * locks so that holding either lock and testing blkcg_policy_enabled() is |
| 1296 | * always enough for dereferencing policy data. |
| 1297 | * |
| 1298 | * The caller is responsible for synchronizing [de]activations and policy |
| 1299 | * [un]registerations. Returns 0 on success, -errno on failure. |
| 1300 | */ |
| 1301 | int blkcg_activate_policy(struct request_queue *q, |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1302 | const struct blkcg_policy *pol) |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1303 | { |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1304 | struct blkg_policy_data *pd_prealloc = NULL; |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1305 | struct blkcg_gq *blkg, *pinned_blkg = NULL; |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1306 | int ret; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1307 | |
| 1308 | if (blkcg_policy_enabled(q, pol)) |
| 1309 | return 0; |
| 1310 | |
Jens Axboe | 344e9ff | 2018-11-15 12:22:51 -0700 | [diff] [blame] | 1311 | if (queue_is_mq(q)) |
Jens Axboe | bd166ef | 2017-01-17 06:03:22 -0700 | [diff] [blame] | 1312 | blk_mq_freeze_queue(q); |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1313 | retry: |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1314 | spin_lock_irq(&q->queue_lock); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1315 | |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1316 | /* blkg_list is pushed at the head, reverse walk to allocate parents first */ |
Tejun Heo | 71c8140 | 2019-06-13 15:30:40 -0700 | [diff] [blame] | 1317 | list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) { |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1318 | struct blkg_policy_data *pd; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1319 | |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1320 | if (blkg->pd[pol->plid]) |
| 1321 | continue; |
| 1322 | |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1323 | /* If prealloc matches, use it; otherwise try GFP_NOWAIT */ |
| 1324 | if (blkg == pinned_blkg) { |
| 1325 | pd = pd_prealloc; |
| 1326 | pd_prealloc = NULL; |
| 1327 | } else { |
| 1328 | pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q, |
| 1329 | blkg->blkcg); |
| 1330 | } |
| 1331 | |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1332 | if (!pd) { |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1333 | /* |
| 1334 | * GFP_NOWAIT failed. Free the existing one and |
| 1335 | * prealloc for @blkg w/ GFP_KERNEL. |
| 1336 | */ |
| 1337 | if (pinned_blkg) |
| 1338 | blkg_put(pinned_blkg); |
| 1339 | blkg_get(blkg); |
| 1340 | pinned_blkg = blkg; |
| 1341 | |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1342 | spin_unlock_irq(&q->queue_lock); |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1343 | |
| 1344 | if (pd_prealloc) |
| 1345 | pol->pd_free_fn(pd_prealloc); |
| 1346 | pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q, |
| 1347 | blkg->blkcg); |
| 1348 | if (pd_prealloc) |
| 1349 | goto retry; |
| 1350 | else |
| 1351 | goto enomem; |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1352 | } |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1353 | |
| 1354 | blkg->pd[pol->plid] = pd; |
| 1355 | pd->blkg = blkg; |
Tejun Heo | b276a87 | 2013-01-09 08:05:12 -0800 | [diff] [blame] | 1356 | pd->plid = pol->plid; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1357 | } |
| 1358 | |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1359 | /* all allocated, init in the same order */ |
| 1360 | if (pol->pd_init_fn) |
| 1361 | list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) |
| 1362 | pol->pd_init_fn(blkg->pd[pol->plid]); |
| 1363 | |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1364 | __set_bit(pol->plid, q->blkcg_pols); |
| 1365 | ret = 0; |
Tejun Heo | 4c55f4f | 2015-08-18 14:55:09 -0700 | [diff] [blame] | 1366 | |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1367 | spin_unlock_irq(&q->queue_lock); |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1368 | out: |
Jens Axboe | 344e9ff | 2018-11-15 12:22:51 -0700 | [diff] [blame] | 1369 | if (queue_is_mq(q)) |
Jens Axboe | bd166ef | 2017-01-17 06:03:22 -0700 | [diff] [blame] | 1370 | blk_mq_unfreeze_queue(q); |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1371 | if (pinned_blkg) |
| 1372 | blkg_put(pinned_blkg); |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1373 | if (pd_prealloc) |
| 1374 | pol->pd_free_fn(pd_prealloc); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1375 | return ret; |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1376 | |
| 1377 | enomem: |
| 1378 | /* alloc failed, nothing's initialized yet, free everything */ |
| 1379 | spin_lock_irq(&q->queue_lock); |
| 1380 | list_for_each_entry(blkg, &q->blkg_list, q_node) { |
Li Jinlin | 858560b | 2021-09-14 12:26:05 +0800 | [diff] [blame] | 1381 | struct blkcg *blkcg = blkg->blkcg; |
| 1382 | |
| 1383 | spin_lock(&blkcg->lock); |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1384 | if (blkg->pd[pol->plid]) { |
| 1385 | pol->pd_free_fn(blkg->pd[pol->plid]); |
| 1386 | blkg->pd[pol->plid] = NULL; |
| 1387 | } |
Li Jinlin | 858560b | 2021-09-14 12:26:05 +0800 | [diff] [blame] | 1388 | spin_unlock(&blkcg->lock); |
Tejun Heo | 9d179b8 | 2019-10-15 09:03:47 -0700 | [diff] [blame] | 1389 | } |
| 1390 | spin_unlock_irq(&q->queue_lock); |
| 1391 | ret = -ENOMEM; |
| 1392 | goto out; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1393 | } |
| 1394 | EXPORT_SYMBOL_GPL(blkcg_activate_policy); |
| 1395 | |
| 1396 | /** |
| 1397 | * blkcg_deactivate_policy - deactivate a blkcg policy on a request_queue |
| 1398 | * @q: request_queue of interest |
| 1399 | * @pol: blkcg policy to deactivate |
| 1400 | * |
| 1401 | * Deactivate @pol on @q. Follows the same synchronization rules as |
| 1402 | * blkcg_activate_policy(). |
| 1403 | */ |
| 1404 | void blkcg_deactivate_policy(struct request_queue *q, |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1405 | const struct blkcg_policy *pol) |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1406 | { |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1407 | struct blkcg_gq *blkg; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1408 | |
| 1409 | if (!blkcg_policy_enabled(q, pol)) |
| 1410 | return; |
| 1411 | |
Jens Axboe | 344e9ff | 2018-11-15 12:22:51 -0700 | [diff] [blame] | 1412 | if (queue_is_mq(q)) |
Jens Axboe | bd166ef | 2017-01-17 06:03:22 -0700 | [diff] [blame] | 1413 | blk_mq_freeze_queue(q); |
Jens Axboe | bd166ef | 2017-01-17 06:03:22 -0700 | [diff] [blame] | 1414 | |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1415 | spin_lock_irq(&q->queue_lock); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1416 | |
| 1417 | __clear_bit(pol->plid, q->blkcg_pols); |
| 1418 | |
| 1419 | list_for_each_entry(blkg, &q->blkg_list, q_node) { |
Li Jinlin | 858560b | 2021-09-14 12:26:05 +0800 | [diff] [blame] | 1420 | struct blkcg *blkcg = blkg->blkcg; |
| 1421 | |
| 1422 | spin_lock(&blkcg->lock); |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1423 | if (blkg->pd[pol->plid]) { |
Dennis Zhou (Facebook) | 6b06546 | 2018-08-31 16:22:42 -0400 | [diff] [blame] | 1424 | if (pol->pd_offline_fn) |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 1425 | pol->pd_offline_fn(blkg->pd[pol->plid]); |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1426 | pol->pd_free_fn(blkg->pd[pol->plid]); |
| 1427 | blkg->pd[pol->plid] = NULL; |
| 1428 | } |
Li Jinlin | 858560b | 2021-09-14 12:26:05 +0800 | [diff] [blame] | 1429 | spin_unlock(&blkcg->lock); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1430 | } |
| 1431 | |
Christoph Hellwig | 0d945c1 | 2018-11-15 12:17:28 -0700 | [diff] [blame] | 1432 | spin_unlock_irq(&q->queue_lock); |
Jens Axboe | bd166ef | 2017-01-17 06:03:22 -0700 | [diff] [blame] | 1433 | |
Jens Axboe | 344e9ff | 2018-11-15 12:22:51 -0700 | [diff] [blame] | 1434 | if (queue_is_mq(q)) |
Jens Axboe | bd166ef | 2017-01-17 06:03:22 -0700 | [diff] [blame] | 1435 | blk_mq_unfreeze_queue(q); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1436 | } |
| 1437 | EXPORT_SYMBOL_GPL(blkcg_deactivate_policy); |
| 1438 | |
| 1439 | /** |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1440 | * blkcg_policy_register - register a blkcg policy |
| 1441 | * @pol: blkcg policy to register |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1442 | * |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1443 | * Register @pol with blkcg core. Might sleep and @pol may be modified on |
| 1444 | * successful registration. Returns 0 on success and -errno on failure. |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1445 | */ |
Jens Axboe | d5bf029 | 2014-06-22 16:31:56 -0600 | [diff] [blame] | 1446 | int blkcg_policy_register(struct blkcg_policy *pol) |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 1447 | { |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1448 | struct blkcg *blkcg; |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1449 | int i, ret; |
Tejun Heo | e8989fa | 2012-03-05 13:15:20 -0800 | [diff] [blame] | 1450 | |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1451 | mutex_lock(&blkcg_pol_register_mutex); |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 1452 | mutex_lock(&blkcg_pol_mutex); |
| 1453 | |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1454 | /* find an empty slot */ |
| 1455 | ret = -ENOSPC; |
| 1456 | for (i = 0; i < BLKCG_MAX_POLS; i++) |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1457 | if (!blkcg_policy[i]) |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1458 | break; |
Jens Axboe | 01c5f85 | 2018-09-11 10:59:53 -0600 | [diff] [blame] | 1459 | if (i >= BLKCG_MAX_POLS) { |
| 1460 | pr_warn("blkcg_policy_register: BLKCG_MAX_POLS too small\n"); |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1461 | goto err_unlock; |
Jens Axboe | 01c5f85 | 2018-09-11 10:59:53 -0600 | [diff] [blame] | 1462 | } |
Tejun Heo | 035d10b | 2012-03-05 13:15:04 -0800 | [diff] [blame] | 1463 | |
weiping zhang | e840107 | 2017-10-17 23:56:21 +0800 | [diff] [blame] | 1464 | /* Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs */ |
| 1465 | if ((!pol->cpd_alloc_fn ^ !pol->cpd_free_fn) || |
| 1466 | (!pol->pd_alloc_fn ^ !pol->pd_free_fn)) |
| 1467 | goto err_unlock; |
| 1468 | |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1469 | /* register @pol */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1470 | pol->plid = i; |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1471 | blkcg_policy[pol->plid] = pol; |
| 1472 | |
| 1473 | /* allocate and install cpd's */ |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1474 | if (pol->cpd_alloc_fn) { |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1475 | list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { |
| 1476 | struct blkcg_policy_data *cpd; |
| 1477 | |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1478 | cpd = pol->cpd_alloc_fn(GFP_KERNEL); |
Bart Van Assche | bbb427e | 2016-09-29 08:33:30 -0700 | [diff] [blame] | 1479 | if (!cpd) |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1480 | goto err_free_cpds; |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1481 | |
Tejun Heo | 8143764 | 2015-08-18 14:55:15 -0700 | [diff] [blame] | 1482 | blkcg->cpd[pol->plid] = cpd; |
| 1483 | cpd->blkcg = blkcg; |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1484 | cpd->plid = pol->plid; |
Tejun Heo | 86a5bba | 2019-08-28 15:05:52 -0700 | [diff] [blame] | 1485 | if (pol->cpd_init_fn) |
| 1486 | pol->cpd_init_fn(cpd); |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1487 | } |
| 1488 | } |
| 1489 | |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1490 | mutex_unlock(&blkcg_pol_mutex); |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1491 | |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1492 | /* everything is in place, add intf files for the new policy */ |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1493 | if (pol->dfl_cftypes) |
| 1494 | WARN_ON(cgroup_add_dfl_cftypes(&io_cgrp_subsys, |
| 1495 | pol->dfl_cftypes)); |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1496 | if (pol->legacy_cftypes) |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 1497 | WARN_ON(cgroup_add_legacy_cftypes(&io_cgrp_subsys, |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1498 | pol->legacy_cftypes)); |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1499 | mutex_unlock(&blkcg_pol_register_mutex); |
| 1500 | return 0; |
| 1501 | |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1502 | err_free_cpds: |
weiping zhang | 58a9edc | 2017-10-10 22:53:46 +0800 | [diff] [blame] | 1503 | if (pol->cpd_free_fn) { |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1504 | list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1505 | if (blkcg->cpd[pol->plid]) { |
| 1506 | pol->cpd_free_fn(blkcg->cpd[pol->plid]); |
| 1507 | blkcg->cpd[pol->plid] = NULL; |
| 1508 | } |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1509 | } |
| 1510 | } |
| 1511 | blkcg_policy[pol->plid] = NULL; |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1512 | err_unlock: |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 1513 | mutex_unlock(&blkcg_pol_mutex); |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1514 | mutex_unlock(&blkcg_pol_register_mutex); |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1515 | return ret; |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 1516 | } |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1517 | EXPORT_SYMBOL_GPL(blkcg_policy_register); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 1518 | |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1519 | /** |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1520 | * blkcg_policy_unregister - unregister a blkcg policy |
| 1521 | * @pol: blkcg policy to unregister |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1522 | * |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1523 | * Undo blkcg_policy_register(@pol). Might sleep. |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1524 | */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1525 | void blkcg_policy_unregister(struct blkcg_policy *pol) |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 1526 | { |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1527 | struct blkcg *blkcg; |
| 1528 | |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1529 | mutex_lock(&blkcg_pol_register_mutex); |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 1530 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1531 | if (WARN_ON(blkcg_policy[pol->plid] != pol)) |
Tejun Heo | 8bd435b | 2012-04-13 13:11:28 -0700 | [diff] [blame] | 1532 | goto out_unlock; |
| 1533 | |
| 1534 | /* kill the intf files first */ |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1535 | if (pol->dfl_cftypes) |
| 1536 | cgroup_rm_cftypes(pol->dfl_cftypes); |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1537 | if (pol->legacy_cftypes) |
| 1538 | cgroup_rm_cftypes(pol->legacy_cftypes); |
Tejun Heo | 44ea53d | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1539 | |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1540 | /* remove cpds and unregister */ |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1541 | mutex_lock(&blkcg_pol_mutex); |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1542 | |
weiping zhang | 58a9edc | 2017-10-10 22:53:46 +0800 | [diff] [blame] | 1543 | if (pol->cpd_free_fn) { |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1544 | list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { |
Tejun Heo | e4a9bde | 2015-08-18 14:55:16 -0700 | [diff] [blame] | 1545 | if (blkcg->cpd[pol->plid]) { |
| 1546 | pol->cpd_free_fn(blkcg->cpd[pol->plid]); |
| 1547 | blkcg->cpd[pol->plid] = NULL; |
| 1548 | } |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1549 | } |
| 1550 | } |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1551 | blkcg_policy[pol->plid] = NULL; |
Tejun Heo | 06b285b | 2015-07-09 16:39:50 -0400 | [diff] [blame] | 1552 | |
Tejun Heo | bc0d650 | 2012-04-13 13:11:26 -0700 | [diff] [blame] | 1553 | mutex_unlock(&blkcg_pol_mutex); |
Tejun Heo | 838f13b | 2015-07-09 16:39:47 -0400 | [diff] [blame] | 1554 | out_unlock: |
| 1555 | mutex_unlock(&blkcg_pol_register_mutex); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 1556 | } |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1557 | EXPORT_SYMBOL_GPL(blkcg_policy_unregister); |
Josef Bacik | 903d23f | 2018-07-03 11:14:52 -0400 | [diff] [blame] | 1558 | |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 1559 | bool __blkcg_punt_bio_submit(struct bio *bio) |
| 1560 | { |
| 1561 | struct blkcg_gq *blkg = bio->bi_blkg; |
| 1562 | |
| 1563 | /* consume the flag first */ |
| 1564 | bio->bi_opf &= ~REQ_CGROUP_PUNT; |
| 1565 | |
| 1566 | /* never bounce for the root cgroup */ |
| 1567 | if (!blkg->parent) |
| 1568 | return false; |
| 1569 | |
| 1570 | spin_lock_bh(&blkg->async_bio_lock); |
| 1571 | bio_list_add(&blkg->async_bios, bio); |
| 1572 | spin_unlock_bh(&blkg->async_bio_lock); |
| 1573 | |
| 1574 | queue_work(blkcg_punt_bio_wq, &blkg->async_bio_work); |
| 1575 | return true; |
| 1576 | } |
| 1577 | |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1578 | /* |
| 1579 | * Scale the accumulated delay based on how long it has been since we updated |
| 1580 | * the delay. We only call this when we are adding delay, in case it's been a |
| 1581 | * while since we added delay, and when we are checking to see if we need to |
| 1582 | * delay a task, to account for any delays that may have occurred. |
| 1583 | */ |
| 1584 | static void blkcg_scale_delay(struct blkcg_gq *blkg, u64 now) |
| 1585 | { |
| 1586 | u64 old = atomic64_read(&blkg->delay_start); |
| 1587 | |
Tejun Heo | 54c52e1 | 2020-04-13 12:27:55 -0400 | [diff] [blame] | 1588 | /* negative use_delay means no scaling, see blkcg_set_delay() */ |
| 1589 | if (atomic_read(&blkg->use_delay) < 0) |
| 1590 | return; |
| 1591 | |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1592 | /* |
| 1593 | * We only want to scale down every second. The idea here is that we |
| 1594 | * want to delay people for min(delay_nsec, NSEC_PER_SEC) in a certain |
| 1595 | * time window. We only want to throttle tasks for recent delay that |
| 1596 | * has occurred, in 1 second time windows since that's the maximum |
| 1597 | * things can be throttled. We save the current delay window in |
| 1598 | * blkg->last_delay so we know what amount is still left to be charged |
| 1599 | * to the blkg from this point onward. blkg->last_use keeps track of |
| 1600 | * the use_delay counter. The idea is if we're unthrottling the blkg we |
| 1601 | * are ok with whatever is happening now, and we can take away more of |
| 1602 | * the accumulated delay as we've already throttled enough that |
| 1603 | * everybody is happy with their IO latencies. |
| 1604 | */ |
| 1605 | if (time_before64(old + NSEC_PER_SEC, now) && |
| 1606 | atomic64_cmpxchg(&blkg->delay_start, old, now) == old) { |
| 1607 | u64 cur = atomic64_read(&blkg->delay_nsec); |
| 1608 | u64 sub = min_t(u64, blkg->last_delay, now - old); |
| 1609 | int cur_use = atomic_read(&blkg->use_delay); |
| 1610 | |
| 1611 | /* |
| 1612 | * We've been unthrottled, subtract a larger chunk of our |
| 1613 | * accumulated delay. |
| 1614 | */ |
| 1615 | if (cur_use < blkg->last_use) |
| 1616 | sub = max_t(u64, sub, blkg->last_delay >> 1); |
| 1617 | |
| 1618 | /* |
| 1619 | * This shouldn't happen, but handle it anyway. Our delay_nsec |
| 1620 | * should only ever be growing except here where we subtract out |
| 1621 | * min(last_delay, 1 second), but lord knows bugs happen and I'd |
| 1622 | * rather not end up with negative numbers. |
| 1623 | */ |
| 1624 | if (unlikely(cur < sub)) { |
| 1625 | atomic64_set(&blkg->delay_nsec, 0); |
| 1626 | blkg->last_delay = 0; |
| 1627 | } else { |
| 1628 | atomic64_sub(sub, &blkg->delay_nsec); |
| 1629 | blkg->last_delay = cur - sub; |
| 1630 | } |
| 1631 | blkg->last_use = cur_use; |
| 1632 | } |
| 1633 | } |
| 1634 | |
| 1635 | /* |
| 1636 | * This is called when we want to actually walk up the hierarchy and check to |
| 1637 | * see if we need to throttle, and then actually throttle if there is some |
| 1638 | * accumulated delay. This should only be called upon return to user space so |
| 1639 | * we're not holding some lock that would induce a priority inversion. |
| 1640 | */ |
| 1641 | static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay) |
| 1642 | { |
Josef Bacik | fd112c7 | 2019-07-09 14:41:29 -0700 | [diff] [blame] | 1643 | unsigned long pflags; |
Tejun Heo | 5160a5a | 2020-09-01 14:52:52 -0400 | [diff] [blame] | 1644 | bool clamp; |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1645 | u64 now = ktime_to_ns(ktime_get()); |
| 1646 | u64 exp; |
| 1647 | u64 delay_nsec = 0; |
| 1648 | int tok; |
| 1649 | |
| 1650 | while (blkg->parent) { |
Tejun Heo | 5160a5a | 2020-09-01 14:52:52 -0400 | [diff] [blame] | 1651 | int use_delay = atomic_read(&blkg->use_delay); |
| 1652 | |
| 1653 | if (use_delay) { |
| 1654 | u64 this_delay; |
| 1655 | |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1656 | blkcg_scale_delay(blkg, now); |
Tejun Heo | 5160a5a | 2020-09-01 14:52:52 -0400 | [diff] [blame] | 1657 | this_delay = atomic64_read(&blkg->delay_nsec); |
| 1658 | if (this_delay > delay_nsec) { |
| 1659 | delay_nsec = this_delay; |
| 1660 | clamp = use_delay > 0; |
| 1661 | } |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1662 | } |
| 1663 | blkg = blkg->parent; |
| 1664 | } |
| 1665 | |
| 1666 | if (!delay_nsec) |
| 1667 | return; |
| 1668 | |
| 1669 | /* |
| 1670 | * Let's not sleep for all eternity if we've amassed a huge delay. |
| 1671 | * Swapping or metadata IO can accumulate 10's of seconds worth of |
| 1672 | * delay, and we want userspace to be able to do _something_ so cap the |
Tejun Heo | 5160a5a | 2020-09-01 14:52:52 -0400 | [diff] [blame] | 1673 | * delays at 0.25s. If there's 10's of seconds worth of delay then the |
| 1674 | * tasks will be delayed for 0.25 second for every syscall. If |
| 1675 | * blkcg_set_delay() was used as indicated by negative use_delay, the |
| 1676 | * caller is responsible for regulating the range. |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1677 | */ |
Tejun Heo | 5160a5a | 2020-09-01 14:52:52 -0400 | [diff] [blame] | 1678 | if (clamp) |
| 1679 | delay_nsec = min_t(u64, delay_nsec, 250 * NSEC_PER_MSEC); |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1680 | |
Josef Bacik | fd112c7 | 2019-07-09 14:41:29 -0700 | [diff] [blame] | 1681 | if (use_memdelay) |
| 1682 | psi_memstall_enter(&pflags); |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1683 | |
| 1684 | exp = ktime_add_ns(now, delay_nsec); |
| 1685 | tok = io_schedule_prepare(); |
| 1686 | do { |
| 1687 | __set_current_state(TASK_KILLABLE); |
| 1688 | if (!schedule_hrtimeout(&exp, HRTIMER_MODE_ABS)) |
| 1689 | break; |
| 1690 | } while (!fatal_signal_pending(current)); |
| 1691 | io_schedule_finish(tok); |
Josef Bacik | fd112c7 | 2019-07-09 14:41:29 -0700 | [diff] [blame] | 1692 | |
| 1693 | if (use_memdelay) |
| 1694 | psi_memstall_leave(&pflags); |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1695 | } |
| 1696 | |
| 1697 | /** |
| 1698 | * blkcg_maybe_throttle_current - throttle the current task if it has been marked |
| 1699 | * |
| 1700 | * This is only called if we've been marked with set_notify_resume(). Obviously |
| 1701 | * we can be set_notify_resume() for reasons other than blkcg throttling, so we |
| 1702 | * check to see if current->throttle_queue is set and if not this doesn't do |
| 1703 | * anything. This should only ever be called by the resume code, it's not meant |
| 1704 | * to be called by people willy-nilly as it will actually do the work to |
| 1705 | * throttle the task if it is setup for throttling. |
| 1706 | */ |
| 1707 | void blkcg_maybe_throttle_current(void) |
| 1708 | { |
| 1709 | struct request_queue *q = current->throttle_queue; |
| 1710 | struct cgroup_subsys_state *css; |
| 1711 | struct blkcg *blkcg; |
| 1712 | struct blkcg_gq *blkg; |
| 1713 | bool use_memdelay = current->use_memdelay; |
| 1714 | |
| 1715 | if (!q) |
| 1716 | return; |
| 1717 | |
| 1718 | current->throttle_queue = NULL; |
| 1719 | current->use_memdelay = false; |
| 1720 | |
| 1721 | rcu_read_lock(); |
| 1722 | css = kthread_blkcg(); |
| 1723 | if (css) |
| 1724 | blkcg = css_to_blkcg(css); |
| 1725 | else |
| 1726 | blkcg = css_to_blkcg(task_css(current, io_cgrp_id)); |
| 1727 | |
| 1728 | if (!blkcg) |
| 1729 | goto out; |
| 1730 | blkg = blkg_lookup(blkcg, q); |
| 1731 | if (!blkg) |
| 1732 | goto out; |
Dennis Zhou | 7754f66 | 2018-12-05 12:10:39 -0500 | [diff] [blame] | 1733 | if (!blkg_tryget(blkg)) |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1734 | goto out; |
| 1735 | rcu_read_unlock(); |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1736 | |
| 1737 | blkcg_maybe_throttle_blkg(blkg, use_memdelay); |
| 1738 | blkg_put(blkg); |
Josef Bacik | cc7ecc25 | 2018-07-31 12:39:03 -0400 | [diff] [blame] | 1739 | blk_put_queue(q); |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1740 | return; |
| 1741 | out: |
| 1742 | rcu_read_unlock(); |
| 1743 | blk_put_queue(q); |
| 1744 | } |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1745 | |
| 1746 | /** |
| 1747 | * blkcg_schedule_throttle - this task needs to check for throttling |
Bart Van Assche | 537d71b | 2019-03-20 13:18:45 -0700 | [diff] [blame] | 1748 | * @q: the request queue IO was submitted on |
| 1749 | * @use_memdelay: do we charge this to memory delay for PSI |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1750 | * |
| 1751 | * This is called by the IO controller when we know there's delay accumulated |
| 1752 | * for the blkg for this task. We do not pass the blkg because there are places |
| 1753 | * we call this that may not have that information, the swapping code for |
| 1754 | * instance will only have a request_queue at that point. This set's the |
| 1755 | * notify_resume for the task to check and see if it requires throttling before |
| 1756 | * returning to user space. |
| 1757 | * |
| 1758 | * We will only schedule once per syscall. You can call this over and over |
| 1759 | * again and it will only do the check once upon return to user space, and only |
| 1760 | * throttle once. If the task needs to be throttled again it'll need to be |
| 1761 | * re-set at the next time we see the task. |
| 1762 | */ |
| 1763 | void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) |
| 1764 | { |
| 1765 | if (unlikely(current->flags & PF_KTHREAD)) |
| 1766 | return; |
| 1767 | |
Chunguang Xu | 49d1822 | 2021-01-25 13:05:28 +0800 | [diff] [blame] | 1768 | if (current->throttle_queue != q) { |
| 1769 | if (!blk_get_queue(q)) |
| 1770 | return; |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1771 | |
Chunguang Xu | 49d1822 | 2021-01-25 13:05:28 +0800 | [diff] [blame] | 1772 | if (current->throttle_queue) |
| 1773 | blk_put_queue(current->throttle_queue); |
| 1774 | current->throttle_queue = q; |
| 1775 | } |
| 1776 | |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1777 | if (use_memdelay) |
| 1778 | current->use_memdelay = use_memdelay; |
| 1779 | set_notify_resume(current); |
| 1780 | } |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1781 | |
| 1782 | /** |
| 1783 | * blkcg_add_delay - add delay to this blkg |
Bart Van Assche | 537d71b | 2019-03-20 13:18:45 -0700 | [diff] [blame] | 1784 | * @blkg: blkg of interest |
| 1785 | * @now: the current time in nanoseconds |
| 1786 | * @delta: how many nanoseconds of delay to add |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1787 | * |
| 1788 | * Charge @delta to the blkg's current delay accumulation. This is used to |
| 1789 | * throttle tasks if an IO controller thinks we need more throttling. |
| 1790 | */ |
| 1791 | void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta) |
| 1792 | { |
Tejun Heo | 54c52e1 | 2020-04-13 12:27:55 -0400 | [diff] [blame] | 1793 | if (WARN_ON_ONCE(atomic_read(&blkg->use_delay) < 0)) |
| 1794 | return; |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1795 | blkcg_scale_delay(blkg, now); |
| 1796 | atomic64_add(delta, &blkg->delay_nsec); |
| 1797 | } |
Josef Bacik | d09d8df | 2018-07-03 11:14:55 -0400 | [diff] [blame] | 1798 | |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1799 | /** |
| 1800 | * blkg_tryget_closest - try and get a blkg ref on the closet blkg |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1801 | * @bio: target bio |
| 1802 | * @css: target css |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1803 | * |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1804 | * As the failure mode here is to walk up the blkg tree, this ensure that the |
| 1805 | * blkg->parent pointers are always valid. This returns the blkg that it ended |
| 1806 | * up taking a reference on or %NULL if no reference was taken. |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1807 | */ |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1808 | static inline struct blkcg_gq *blkg_tryget_closest(struct bio *bio, |
| 1809 | struct cgroup_subsys_state *css) |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1810 | { |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1811 | struct blkcg_gq *blkg, *ret_blkg = NULL; |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1812 | |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1813 | rcu_read_lock(); |
Christoph Hellwig | 309dca30 | 2021-01-24 11:02:34 +0100 | [diff] [blame] | 1814 | blkg = blkg_lookup_create(css_to_blkcg(css), |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 1815 | bdev_get_queue(bio->bi_bdev)); |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1816 | while (blkg) { |
| 1817 | if (blkg_tryget(blkg)) { |
| 1818 | ret_blkg = blkg; |
| 1819 | break; |
| 1820 | } |
| 1821 | blkg = blkg->parent; |
| 1822 | } |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1823 | rcu_read_unlock(); |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1824 | |
| 1825 | return ret_blkg; |
| 1826 | } |
| 1827 | |
| 1828 | /** |
| 1829 | * bio_associate_blkg_from_css - associate a bio with a specified css |
| 1830 | * @bio: target bio |
| 1831 | * @css: target css |
| 1832 | * |
| 1833 | * Associate @bio with the blkg found by combining the css's blkg and the |
| 1834 | * request_queue of the @bio. An association failure is handled by walking up |
| 1835 | * the blkg tree. Therefore, the blkg associated can be anything between @blkg |
| 1836 | * and q->root_blkg. This situation only happens when a cgroup is dying and |
| 1837 | * then the remaining bios will spill to the closest alive blkg. |
| 1838 | * |
| 1839 | * A reference will be taken on the blkg and will be released when @bio is |
| 1840 | * freed. |
| 1841 | */ |
| 1842 | void bio_associate_blkg_from_css(struct bio *bio, |
| 1843 | struct cgroup_subsys_state *css) |
| 1844 | { |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1845 | if (bio->bi_blkg) |
| 1846 | blkg_put(bio->bi_blkg); |
| 1847 | |
Christoph Hellwig | a5b9752 | 2020-06-27 09:31:53 +0200 | [diff] [blame] | 1848 | if (css && css->parent) { |
Christoph Hellwig | 13c7863 | 2020-06-27 09:31:54 +0200 | [diff] [blame] | 1849 | bio->bi_blkg = blkg_tryget_closest(bio, css); |
Christoph Hellwig | a5b9752 | 2020-06-27 09:31:53 +0200 | [diff] [blame] | 1850 | } else { |
Pavel Begunkov | ed6cdde | 2021-10-14 15:03:30 +0100 | [diff] [blame] | 1851 | blkg_get(bdev_get_queue(bio->bi_bdev)->root_blkg); |
| 1852 | bio->bi_blkg = bdev_get_queue(bio->bi_bdev)->root_blkg; |
Christoph Hellwig | a5b9752 | 2020-06-27 09:31:53 +0200 | [diff] [blame] | 1853 | } |
Christoph Hellwig | 28fc591 | 2020-06-27 09:31:51 +0200 | [diff] [blame] | 1854 | } |
| 1855 | EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); |
| 1856 | |
| 1857 | /** |
| 1858 | * bio_associate_blkg - associate a bio with a blkg |
| 1859 | * @bio: target bio |
| 1860 | * |
| 1861 | * Associate @bio with the blkg found from the bio's css and request_queue. |
| 1862 | * If one is not found, bio_lookup_blkg() creates the blkg. If a blkg is |
| 1863 | * already associated, the css is reused and association redone as the |
| 1864 | * request_queue may have changed. |
| 1865 | */ |
| 1866 | void bio_associate_blkg(struct bio *bio) |
| 1867 | { |
| 1868 | struct cgroup_subsys_state *css; |
| 1869 | |
| 1870 | rcu_read_lock(); |
| 1871 | |
| 1872 | if (bio->bi_blkg) |
| 1873 | css = &bio_blkcg(bio)->css; |
| 1874 | else |
| 1875 | css = blkcg_css(); |
| 1876 | |
| 1877 | bio_associate_blkg_from_css(bio, css); |
| 1878 | |
| 1879 | rcu_read_unlock(); |
| 1880 | } |
| 1881 | EXPORT_SYMBOL_GPL(bio_associate_blkg); |
| 1882 | |
| 1883 | /** |
| 1884 | * bio_clone_blkg_association - clone blkg association from src to dst bio |
| 1885 | * @dst: destination bio |
| 1886 | * @src: source bio |
| 1887 | */ |
| 1888 | void bio_clone_blkg_association(struct bio *dst, struct bio *src) |
| 1889 | { |
| 1890 | if (src->bi_blkg) { |
| 1891 | if (dst->bi_blkg) |
| 1892 | blkg_put(dst->bi_blkg); |
| 1893 | blkg_get(src->bi_blkg); |
| 1894 | dst->bi_blkg = src->bi_blkg; |
| 1895 | } |
| 1896 | } |
| 1897 | EXPORT_SYMBOL_GPL(bio_clone_blkg_association); |
| 1898 | |
Christoph Hellwig | db18a53 | 2020-06-27 09:31:58 +0200 | [diff] [blame] | 1899 | static int blk_cgroup_io_type(struct bio *bio) |
| 1900 | { |
| 1901 | if (op_is_discard(bio->bi_opf)) |
| 1902 | return BLKG_IOSTAT_DISCARD; |
| 1903 | if (op_is_write(bio->bi_opf)) |
| 1904 | return BLKG_IOSTAT_WRITE; |
| 1905 | return BLKG_IOSTAT_READ; |
| 1906 | } |
| 1907 | |
| 1908 | void blk_cgroup_bio_start(struct bio *bio) |
| 1909 | { |
| 1910 | int rwd = blk_cgroup_io_type(bio), cpu; |
| 1911 | struct blkg_iostat_set *bis; |
Tejun Heo | 3c08b09 | 2021-10-14 13:20:22 -1000 | [diff] [blame] | 1912 | unsigned long flags; |
Christoph Hellwig | db18a53 | 2020-06-27 09:31:58 +0200 | [diff] [blame] | 1913 | |
| 1914 | cpu = get_cpu(); |
| 1915 | bis = per_cpu_ptr(bio->bi_blkg->iostat_cpu, cpu); |
Tejun Heo | 3c08b09 | 2021-10-14 13:20:22 -1000 | [diff] [blame] | 1916 | flags = u64_stats_update_begin_irqsave(&bis->sync); |
Christoph Hellwig | db18a53 | 2020-06-27 09:31:58 +0200 | [diff] [blame] | 1917 | |
| 1918 | /* |
| 1919 | * If the bio is flagged with BIO_CGROUP_ACCT it means this is a split |
| 1920 | * bio and we would have already accounted for the size of the bio. |
| 1921 | */ |
| 1922 | if (!bio_flagged(bio, BIO_CGROUP_ACCT)) { |
| 1923 | bio_set_flag(bio, BIO_CGROUP_ACCT); |
Colin Ian King | 0b8cc25 | 2020-06-30 16:54:41 +0100 | [diff] [blame] | 1924 | bis->cur.bytes[rwd] += bio->bi_iter.bi_size; |
Christoph Hellwig | db18a53 | 2020-06-27 09:31:58 +0200 | [diff] [blame] | 1925 | } |
| 1926 | bis->cur.ios[rwd]++; |
| 1927 | |
Tejun Heo | 3c08b09 | 2021-10-14 13:20:22 -1000 | [diff] [blame] | 1928 | u64_stats_update_end_irqrestore(&bis->sync, flags); |
Christoph Hellwig | db18a53 | 2020-06-27 09:31:58 +0200 | [diff] [blame] | 1929 | if (cgroup_subsys_on_dfl(io_cgrp_subsys)) |
| 1930 | cgroup_rstat_updated(bio->bi_blkg->blkcg->css.cgroup, cpu); |
| 1931 | put_cpu(); |
| 1932 | } |
| 1933 | |
Tejun Heo | d3f77df | 2019-06-27 13:39:52 -0700 | [diff] [blame] | 1934 | static int __init blkcg_init(void) |
| 1935 | { |
| 1936 | blkcg_punt_bio_wq = alloc_workqueue("blkcg_punt_bio", |
| 1937 | WQ_MEM_RECLAIM | WQ_FREEZABLE | |
| 1938 | WQ_UNBOUND | WQ_SYSFS, 0); |
| 1939 | if (!blkcg_punt_bio_wq) |
| 1940 | return -ENOMEM; |
| 1941 | return 0; |
| 1942 | } |
| 1943 | subsys_initcall(blkcg_init); |
| 1944 | |
Josef Bacik | 903d23f | 2018-07-03 11:14:52 -0400 | [diff] [blame] | 1945 | module_param(blkcg_debug_stats, bool, 0644); |
| 1946 | MODULE_PARM_DESC(blkcg_debug_stats, "True if you want debug stats, false if not"); |