block: fix crash in 'blk_mq_elv_switch_none'
[linux-block.git] / block / blk-mq-sysfs.c
CommitLineData
3dcf60bc 1// SPDX-License-Identifier: GPL-2.0
320ae51f
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2#include <linux/kernel.h>
3#include <linux/module.h>
4#include <linux/backing-dev.h>
5#include <linux/bio.h>
6#include <linux/blkdev.h>
7#include <linux/mm.h>
8#include <linux/init.h>
9#include <linux/slab.h>
10#include <linux/workqueue.h>
11#include <linux/smp.h>
12
13#include <linux/blk-mq.h>
c7e2d94b 14#include "blk.h"
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15#include "blk-mq.h"
16#include "blk-mq-tag.h"
17
18static void blk_mq_sysfs_release(struct kobject *kobj)
19{
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ML
20 struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
21
22 free_percpu(ctxs->queue_ctx);
23 kfree(ctxs);
24}
25
26static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
27{
28 struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
29
30 /* ctx->ctxs won't be released until all ctx are freed */
31 kobject_put(&ctx->ctxs->kobj);
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32}
33
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34static void blk_mq_hw_sysfs_release(struct kobject *kobj)
35{
36 struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
37 kobj);
c7e2d94b 38
c7e2d94b
ML
39 blk_free_flush_queue(hctx->fq);
40 sbitmap_free(&hctx->ctx_map);
01388df3 41 free_cpumask_var(hctx->cpumask);
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42 kfree(hctx->ctxs);
43 kfree(hctx);
44}
45
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46struct blk_mq_hw_ctx_sysfs_entry {
47 struct attribute attr;
48 ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
49 ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
50};
51
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52static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
53 struct attribute *attr, char *page)
54{
55 struct blk_mq_hw_ctx_sysfs_entry *entry;
56 struct blk_mq_hw_ctx *hctx;
57 struct request_queue *q;
58 ssize_t res;
59
60 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
61 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
62 q = hctx->queue;
63
64 if (!entry->show)
65 return -EIO;
66
320ae51f 67 mutex_lock(&q->sysfs_lock);
bae85c15 68 res = entry->show(hctx, page);
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69 mutex_unlock(&q->sysfs_lock);
70 return res;
71}
72
73static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
74 struct attribute *attr, const char *page,
75 size_t length)
76{
77 struct blk_mq_hw_ctx_sysfs_entry *entry;
78 struct blk_mq_hw_ctx *hctx;
79 struct request_queue *q;
80 ssize_t res;
81
82 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
83 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
84 q = hctx->queue;
85
86 if (!entry->store)
87 return -EIO;
88
320ae51f 89 mutex_lock(&q->sysfs_lock);
bae85c15 90 res = entry->store(hctx, page, length);
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91 mutex_unlock(&q->sysfs_lock);
92 return res;
93}
94
d96b37c0
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95static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
96 char *page)
bd166ef1 97{
d96b37c0 98 return sprintf(page, "%u\n", hctx->tags->nr_tags);
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99}
100
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101static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
102 char *page)
320ae51f 103{
d96b37c0 104 return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
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105}
106
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107static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
108{
8962842c 109 const size_t size = PAGE_SIZE - 1;
cb2da43e 110 unsigned int i, first = 1;
8962842c 111 int ret = 0, pos = 0;
676141e4 112
cb2da43e 113 for_each_cpu(i, hctx->cpumask) {
676141e4 114 if (first)
8962842c 115 ret = snprintf(pos + page, size - pos, "%u", i);
676141e4 116 else
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117 ret = snprintf(pos + page, size - pos, ", %u", i);
118
119 if (ret >= size - pos)
120 break;
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121
122 first = 0;
8962842c 123 pos += ret;
676141e4
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124 }
125
d2c9be89 126 ret = snprintf(pos + page, size + 1 - pos, "\n");
8962842c 127 return pos + ret;
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128}
129
d96b37c0 130static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
5657a819 131 .attr = {.name = "nr_tags", .mode = 0444 },
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OS
132 .show = blk_mq_hw_sysfs_nr_tags_show,
133};
134static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
5657a819 135 .attr = {.name = "nr_reserved_tags", .mode = 0444 },
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136 .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
137};
676141e4 138static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
5657a819 139 .attr = {.name = "cpu_list", .mode = 0444 },
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140 .show = blk_mq_hw_sysfs_cpus_show,
141};
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142
143static struct attribute *default_hw_ctx_attrs[] = {
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144 &blk_mq_hw_sysfs_nr_tags.attr,
145 &blk_mq_hw_sysfs_nr_reserved_tags.attr,
676141e4 146 &blk_mq_hw_sysfs_cpus.attr,
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147 NULL,
148};
800f5aa1 149ATTRIBUTE_GROUPS(default_hw_ctx);
320ae51f 150
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151static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
152 .show = blk_mq_hw_sysfs_show,
153 .store = blk_mq_hw_sysfs_store,
154};
155
156static struct kobj_type blk_mq_ktype = {
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157 .release = blk_mq_sysfs_release,
158};
159
160static struct kobj_type blk_mq_ctx_ktype = {
1db4909e 161 .release = blk_mq_ctx_sysfs_release,
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162};
163
164static struct kobj_type blk_mq_hw_ktype = {
165 .sysfs_ops = &blk_mq_hw_sysfs_ops,
800f5aa1 166 .default_groups = default_hw_ctx_groups,
6c8b232e 167 .release = blk_mq_hw_sysfs_release,
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168};
169
ee3c5db0 170static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
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171{
172 struct blk_mq_ctx *ctx;
173 int i;
174
4593fdbe 175 if (!hctx->nr_ctx)
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176 return;
177
178 hctx_for_each_ctx(hctx, ctx, i)
179 kobject_del(&ctx->kobj);
180
181 kobject_del(&hctx->kobj);
182}
183
ee3c5db0 184static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
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185{
186 struct request_queue *q = hctx->queue;
187 struct blk_mq_ctx *ctx;
188 int i, ret;
189
4593fdbe 190 if (!hctx->nr_ctx)
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191 return 0;
192
1db4909e 193 ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
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194 if (ret)
195 return ret;
196
197 hctx_for_each_ctx(hctx, ctx, i) {
198 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
199 if (ret)
200 break;
201 }
202
203 return ret;
204}
205
868f2f0b
KB
206void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
207{
208 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
209}
210
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211void blk_mq_sysfs_deinit(struct request_queue *q)
212{
213 struct blk_mq_ctx *ctx;
214 int cpu;
215
216 for_each_possible_cpu(cpu) {
217 ctx = per_cpu_ptr(q->queue_ctx, cpu);
218 kobject_put(&ctx->kobj);
219 }
1db4909e 220 kobject_put(q->mq_kobj);
7ea5fe31
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221}
222
737f98cf 223void blk_mq_sysfs_init(struct request_queue *q)
67aec14c 224{
67aec14c 225 struct blk_mq_ctx *ctx;
897bb0c7 226 int cpu;
67aec14c 227
1db4909e 228 kobject_init(q->mq_kobj, &blk_mq_ktype);
67aec14c 229
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230 for_each_possible_cpu(cpu) {
231 ctx = per_cpu_ptr(q->queue_ctx, cpu);
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232
233 kobject_get(q->mq_kobj);
06a41a99 234 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
897bb0c7 235 }
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236}
237
8682b92e 238int blk_mq_sysfs_register(struct gendisk *disk)
320ae51f 239{
8682b92e 240 struct request_queue *q = disk->queue;
320ae51f 241 struct blk_mq_hw_ctx *hctx;
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242 unsigned long i, j;
243 int ret;
320ae51f 244
cecf5d87 245 lockdep_assert_held(&q->sysfs_dir_lock);
4593fdbe 246
8682b92e 247 ret = kobject_add(q->mq_kobj, &disk_to_dev(disk)->kobj, "mq");
320ae51f 248 if (ret < 0)
4593fdbe 249 goto out;
320ae51f 250
1db4909e 251 kobject_uevent(q->mq_kobj, KOBJ_ADD);
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252
253 queue_for_each_hw_ctx(q, hctx, i) {
67aec14c 254 ret = blk_mq_register_hctx(hctx);
320ae51f 255 if (ret)
f05d1ba7 256 goto unreg;
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257 }
258
f05d1ba7 259 q->mq_sysfs_init_done = true;
2d0364c8 260
4593fdbe 261out:
2d0364c8 262 return ret;
f05d1ba7
BVA
263
264unreg:
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265 queue_for_each_hw_ctx(q, hctx, j) {
266 if (j < i)
267 blk_mq_unregister_hctx(hctx);
268 }
f05d1ba7 269
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270 kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
271 kobject_del(q->mq_kobj);
f05d1ba7 272 return ret;
2d0364c8
BVA
273}
274
8682b92e
CH
275void blk_mq_sysfs_unregister(struct gendisk *disk)
276{
277 struct request_queue *q = disk->queue;
278 struct blk_mq_hw_ctx *hctx;
279 unsigned long i;
280
281 lockdep_assert_held(&q->sysfs_dir_lock);
282
283 queue_for_each_hw_ctx(q, hctx, i)
284 blk_mq_unregister_hctx(hctx);
285
286 kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
287 kobject_del(q->mq_kobj);
288
289 q->mq_sysfs_init_done = false;
290}
291
eaa870f9 292void blk_mq_sysfs_unregister_hctxs(struct request_queue *q)
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293{
294 struct blk_mq_hw_ctx *hctx;
4f481208 295 unsigned long i;
67aec14c 296
cecf5d87 297 mutex_lock(&q->sysfs_dir_lock);
4593fdbe 298 if (!q->mq_sysfs_init_done)
2d0364c8 299 goto unlock;
4593fdbe 300
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301 queue_for_each_hw_ctx(q, hctx, i)
302 blk_mq_unregister_hctx(hctx);
2d0364c8
BVA
303
304unlock:
cecf5d87 305 mutex_unlock(&q->sysfs_dir_lock);
67aec14c
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306}
307
eaa870f9 308int blk_mq_sysfs_register_hctxs(struct request_queue *q)
67aec14c
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309{
310 struct blk_mq_hw_ctx *hctx;
4f481208
ML
311 unsigned long i;
312 int ret = 0;
67aec14c 313
cecf5d87 314 mutex_lock(&q->sysfs_dir_lock);
4593fdbe 315 if (!q->mq_sysfs_init_done)
2d0364c8 316 goto unlock;
4593fdbe 317
67aec14c
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318 queue_for_each_hw_ctx(q, hctx, i) {
319 ret = blk_mq_register_hctx(hctx);
320 if (ret)
321 break;
322 }
323
2d0364c8 324unlock:
cecf5d87 325 mutex_unlock(&q->sysfs_dir_lock);
2d0364c8 326
67aec14c
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327 return ret;
328}