Root/block/blk-mq-sysfs.c

1#include <linux/kernel.h>
2#include <linux/module.h>
3#include <linux/backing-dev.h>
4#include <linux/bio.h>
5#include <linux/blkdev.h>
6#include <linux/mm.h>
7#include <linux/init.h>
8#include <linux/slab.h>
9#include <linux/workqueue.h>
10#include <linux/smp.h>
11
12#include <linux/blk-mq.h>
13#include "blk-mq.h"
14#include "blk-mq-tag.h"
15
16static void blk_mq_sysfs_release(struct kobject *kobj)
17{
18}
19
20struct blk_mq_ctx_sysfs_entry {
21    struct attribute attr;
22    ssize_t (*show)(struct blk_mq_ctx *, char *);
23    ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
24};
25
26struct blk_mq_hw_ctx_sysfs_entry {
27    struct attribute attr;
28    ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
29    ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
30};
31
32static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
33                 char *page)
34{
35    struct blk_mq_ctx_sysfs_entry *entry;
36    struct blk_mq_ctx *ctx;
37    struct request_queue *q;
38    ssize_t res;
39
40    entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
41    ctx = container_of(kobj, struct blk_mq_ctx, kobj);
42    q = ctx->queue;
43
44    if (!entry->show)
45        return -EIO;
46
47    res = -ENOENT;
48    mutex_lock(&q->sysfs_lock);
49    if (!blk_queue_dying(q))
50        res = entry->show(ctx, page);
51    mutex_unlock(&q->sysfs_lock);
52    return res;
53}
54
55static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
56                  const char *page, size_t length)
57{
58    struct blk_mq_ctx_sysfs_entry *entry;
59    struct blk_mq_ctx *ctx;
60    struct request_queue *q;
61    ssize_t res;
62
63    entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
64    ctx = container_of(kobj, struct blk_mq_ctx, kobj);
65    q = ctx->queue;
66
67    if (!entry->store)
68        return -EIO;
69
70    res = -ENOENT;
71    mutex_lock(&q->sysfs_lock);
72    if (!blk_queue_dying(q))
73        res = entry->store(ctx, page, length);
74    mutex_unlock(&q->sysfs_lock);
75    return res;
76}
77
78static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
79                    struct attribute *attr, char *page)
80{
81    struct blk_mq_hw_ctx_sysfs_entry *entry;
82    struct blk_mq_hw_ctx *hctx;
83    struct request_queue *q;
84    ssize_t res;
85
86    entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
87    hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
88    q = hctx->queue;
89
90    if (!entry->show)
91        return -EIO;
92
93    res = -ENOENT;
94    mutex_lock(&q->sysfs_lock);
95    if (!blk_queue_dying(q))
96        res = entry->show(hctx, page);
97    mutex_unlock(&q->sysfs_lock);
98    return res;
99}
100
101static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
102                     struct attribute *attr, const char *page,
103                     size_t length)
104{
105    struct blk_mq_hw_ctx_sysfs_entry *entry;
106    struct blk_mq_hw_ctx *hctx;
107    struct request_queue *q;
108    ssize_t res;
109
110    entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
111    hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
112    q = hctx->queue;
113
114    if (!entry->store)
115        return -EIO;
116
117    res = -ENOENT;
118    mutex_lock(&q->sysfs_lock);
119    if (!blk_queue_dying(q))
120        res = entry->store(hctx, page, length);
121    mutex_unlock(&q->sysfs_lock);
122    return res;
123}
124
125static ssize_t blk_mq_sysfs_dispatched_show(struct blk_mq_ctx *ctx, char *page)
126{
127    return sprintf(page, "%lu %lu\n", ctx->rq_dispatched[1],
128                ctx->rq_dispatched[0]);
129}
130
131static ssize_t blk_mq_sysfs_merged_show(struct blk_mq_ctx *ctx, char *page)
132{
133    return sprintf(page, "%lu\n", ctx->rq_merged);
134}
135
136static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page)
137{
138    return sprintf(page, "%lu %lu\n", ctx->rq_completed[1],
139                ctx->rq_completed[0]);
140}
141
142static ssize_t sysfs_list_show(char *page, struct list_head *list, char *msg)
143{
144    char *start_page = page;
145    struct request *rq;
146
147    page += sprintf(page, "%s:\n", msg);
148
149    list_for_each_entry(rq, list, queuelist)
150        page += sprintf(page, "\t%p\n", rq);
151
152    return page - start_page;
153}
154
155static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)
156{
157    ssize_t ret;
158
159    spin_lock(&ctx->lock);
160    ret = sysfs_list_show(page, &ctx->rq_list, "CTX pending");
161    spin_unlock(&ctx->lock);
162
163    return ret;
164}
165
166static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
167                       char *page)
168{
169    return sprintf(page, "%lu\n", hctx->queued);
170}
171
172static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
173{
174    return sprintf(page, "%lu\n", hctx->run);
175}
176
177static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
178                           char *page)
179{
180    char *start_page = page;
181    int i;
182
183    page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
184
185    for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
186        unsigned long d = 1U << (i - 1);
187
188        page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
189    }
190
191    return page - start_page;
192}
193
194static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
195                        char *page)
196{
197    ssize_t ret;
198
199    spin_lock(&hctx->lock);
200    ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
201    spin_unlock(&hctx->lock);
202
203    return ret;
204}
205
206static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
207{
208    return blk_mq_tag_sysfs_show(hctx->tags, page);
209}
210
211static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
212{
213    return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
214}
215
216static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
217{
218    unsigned int i, first = 1;
219    ssize_t ret = 0;
220
221    blk_mq_disable_hotplug();
222
223    for_each_cpu(i, hctx->cpumask) {
224        if (first)
225            ret += sprintf(ret + page, "%u", i);
226        else
227            ret += sprintf(ret + page, ", %u", i);
228
229        first = 0;
230    }
231
232    blk_mq_enable_hotplug();
233
234    ret += sprintf(ret + page, "\n");
235    return ret;
236}
237
238static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
239    .attr = {.name = "dispatched", .mode = S_IRUGO },
240    .show = blk_mq_sysfs_dispatched_show,
241};
242static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
243    .attr = {.name = "merged", .mode = S_IRUGO },
244    .show = blk_mq_sysfs_merged_show,
245};
246static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
247    .attr = {.name = "completed", .mode = S_IRUGO },
248    .show = blk_mq_sysfs_completed_show,
249};
250static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
251    .attr = {.name = "rq_list", .mode = S_IRUGO },
252    .show = blk_mq_sysfs_rq_list_show,
253};
254
255static struct attribute *default_ctx_attrs[] = {
256    &blk_mq_sysfs_dispatched.attr,
257    &blk_mq_sysfs_merged.attr,
258    &blk_mq_sysfs_completed.attr,
259    &blk_mq_sysfs_rq_list.attr,
260    NULL,
261};
262
263static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
264    .attr = {.name = "queued", .mode = S_IRUGO },
265    .show = blk_mq_hw_sysfs_queued_show,
266};
267static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
268    .attr = {.name = "run", .mode = S_IRUGO },
269    .show = blk_mq_hw_sysfs_run_show,
270};
271static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
272    .attr = {.name = "dispatched", .mode = S_IRUGO },
273    .show = blk_mq_hw_sysfs_dispatched_show,
274};
275static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
276    .attr = {.name = "active", .mode = S_IRUGO },
277    .show = blk_mq_hw_sysfs_active_show,
278};
279static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
280    .attr = {.name = "pending", .mode = S_IRUGO },
281    .show = blk_mq_hw_sysfs_rq_list_show,
282};
283static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
284    .attr = {.name = "tags", .mode = S_IRUGO },
285    .show = blk_mq_hw_sysfs_tags_show,
286};
287static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
288    .attr = {.name = "cpu_list", .mode = S_IRUGO },
289    .show = blk_mq_hw_sysfs_cpus_show,
290};
291
292static struct attribute *default_hw_ctx_attrs[] = {
293    &blk_mq_hw_sysfs_queued.attr,
294    &blk_mq_hw_sysfs_run.attr,
295    &blk_mq_hw_sysfs_dispatched.attr,
296    &blk_mq_hw_sysfs_pending.attr,
297    &blk_mq_hw_sysfs_tags.attr,
298    &blk_mq_hw_sysfs_cpus.attr,
299    &blk_mq_hw_sysfs_active.attr,
300    NULL,
301};
302
303static const struct sysfs_ops blk_mq_sysfs_ops = {
304    .show = blk_mq_sysfs_show,
305    .store = blk_mq_sysfs_store,
306};
307
308static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
309    .show = blk_mq_hw_sysfs_show,
310    .store = blk_mq_hw_sysfs_store,
311};
312
313static struct kobj_type blk_mq_ktype = {
314    .sysfs_ops = &blk_mq_sysfs_ops,
315    .release = blk_mq_sysfs_release,
316};
317
318static struct kobj_type blk_mq_ctx_ktype = {
319    .sysfs_ops = &blk_mq_sysfs_ops,
320    .default_attrs = default_ctx_attrs,
321    .release = blk_mq_sysfs_release,
322};
323
324static struct kobj_type blk_mq_hw_ktype = {
325    .sysfs_ops = &blk_mq_hw_sysfs_ops,
326    .default_attrs = default_hw_ctx_attrs,
327    .release = blk_mq_sysfs_release,
328};
329
330static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
331{
332    struct blk_mq_ctx *ctx;
333    int i;
334
335    if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
336        return;
337
338    hctx_for_each_ctx(hctx, ctx, i)
339        kobject_del(&ctx->kobj);
340
341    kobject_del(&hctx->kobj);
342}
343
344static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
345{
346    struct request_queue *q = hctx->queue;
347    struct blk_mq_ctx *ctx;
348    int i, ret;
349
350    if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
351        return 0;
352
353    ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
354    if (ret)
355        return ret;
356
357    hctx_for_each_ctx(hctx, ctx, i) {
358        ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
359        if (ret)
360            break;
361    }
362
363    return ret;
364}
365
366void blk_mq_unregister_disk(struct gendisk *disk)
367{
368    struct request_queue *q = disk->queue;
369    struct blk_mq_hw_ctx *hctx;
370    struct blk_mq_ctx *ctx;
371    int i, j;
372
373    queue_for_each_hw_ctx(q, hctx, i) {
374        blk_mq_unregister_hctx(hctx);
375
376        hctx_for_each_ctx(hctx, ctx, j)
377            kobject_put(&ctx->kobj);
378
379        kobject_put(&hctx->kobj);
380    }
381
382    kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
383    kobject_del(&q->mq_kobj);
384    kobject_put(&q->mq_kobj);
385
386    kobject_put(&disk_to_dev(disk)->kobj);
387}
388
389static void blk_mq_sysfs_init(struct request_queue *q)
390{
391    struct blk_mq_hw_ctx *hctx;
392    struct blk_mq_ctx *ctx;
393    int i, j;
394
395    kobject_init(&q->mq_kobj, &blk_mq_ktype);
396
397    queue_for_each_hw_ctx(q, hctx, i) {
398        kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
399
400        hctx_for_each_ctx(hctx, ctx, j)
401            kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
402    }
403}
404
405int blk_mq_register_disk(struct gendisk *disk)
406{
407    struct device *dev = disk_to_dev(disk);
408    struct request_queue *q = disk->queue;
409    struct blk_mq_hw_ctx *hctx;
410    int ret, i;
411
412    blk_mq_sysfs_init(q);
413
414    ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
415    if (ret < 0)
416        return ret;
417
418    kobject_uevent(&q->mq_kobj, KOBJ_ADD);
419
420    queue_for_each_hw_ctx(q, hctx, i) {
421        hctx->flags |= BLK_MQ_F_SYSFS_UP;
422        ret = blk_mq_register_hctx(hctx);
423        if (ret)
424            break;
425    }
426
427    if (ret) {
428        blk_mq_unregister_disk(disk);
429        return ret;
430    }
431
432    return 0;
433}
434
435void blk_mq_sysfs_unregister(struct request_queue *q)
436{
437    struct blk_mq_hw_ctx *hctx;
438    int i;
439
440    queue_for_each_hw_ctx(q, hctx, i)
441        blk_mq_unregister_hctx(hctx);
442}
443
444int blk_mq_sysfs_register(struct request_queue *q)
445{
446    struct blk_mq_hw_ctx *hctx;
447    int i, ret = 0;
448
449    queue_for_each_hw_ctx(q, hctx, i) {
450        ret = blk_mq_register_hctx(hctx);
451        if (ret)
452            break;
453    }
454
455    return ret;
456}
457

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