xref: /linux/block/blk-mq-sysfs.c (revision db6d8d5fdf9537641c76ba7f32e02b4bcc600972) 
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 
16 static void blk_mq_sysfs_release(struct kobject *kobj)
17 {
18 }
19 
20 struct 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 
26 struct 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 
32 static 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 
55 static 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 
78 static 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 
101 static 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 
125 static 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 
131 static 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 
136 static 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 
142 static ssize_t sysfs_list_show(char *page, struct list_head *list, char *msg)
143 {
144 	struct request *rq;
145 	int len = snprintf(page, PAGE_SIZE - 1, "%s:\n", msg);
146 
147 	list_for_each_entry(rq, list, queuelist) {
148 		const int rq_len = 2 * sizeof(rq) + 2;
149 
150 		/* if the output will be truncated */
151 		if (PAGE_SIZE - 1 < len + rq_len) {
152 			/* backspacing if it can't hold '\t...\n' */
153 			if (PAGE_SIZE - 1 < len + 5)
154 				len -= rq_len;
155 			len += snprintf(page + len, PAGE_SIZE - 1 - len,
156 					"\t...\n");
157 			break;
158 		}
159 		len += snprintf(page + len, PAGE_SIZE - 1 - len,
160 				"\t%p\n", rq);
161 	}
162 
163 	return len;
164 }
165 
166 static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)
167 {
168 	ssize_t ret;
169 
170 	spin_lock(&ctx->lock);
171 	ret = sysfs_list_show(page, &ctx->rq_list, "CTX pending");
172 	spin_unlock(&ctx->lock);
173 
174 	return ret;
175 }
176 
177 static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page)
178 {
179 	return sprintf(page, "considered=%lu, invoked=%lu, success=%lu\n",
180 		       hctx->poll_considered, hctx->poll_invoked,
181 		       hctx->poll_success);
182 }
183 
184 static ssize_t blk_mq_hw_sysfs_poll_store(struct blk_mq_hw_ctx *hctx,
185 					  const char *page, size_t size)
186 {
187 	hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
188 
189 	return size;
190 }
191 
192 static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
193 					   char *page)
194 {
195 	return sprintf(page, "%lu\n", hctx->queued);
196 }
197 
198 static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
199 {
200 	return sprintf(page, "%lu\n", hctx->run);
201 }
202 
203 static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
204 					       char *page)
205 {
206 	char *start_page = page;
207 	int i;
208 
209 	page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
210 
211 	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
212 		unsigned int d = 1U << (i - 1);
213 
214 		page += sprintf(page, "%8u\t%lu\n", d, hctx->dispatched[i]);
215 	}
216 
217 	page += sprintf(page, "%8u+\t%lu\n", 1U << (i - 1),
218 						hctx->dispatched[i]);
219 	return page - start_page;
220 }
221 
222 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
223 					    char *page)
224 {
225 	ssize_t ret;
226 
227 	spin_lock(&hctx->lock);
228 	ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
229 	spin_unlock(&hctx->lock);
230 
231 	return ret;
232 }
233 
234 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
235 {
236 	return blk_mq_tag_sysfs_show(hctx->tags, page);
237 }
238 
239 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
240 {
241 	return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
242 }
243 
244 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
245 {
246 	unsigned int i, first = 1;
247 	ssize_t ret = 0;
248 
249 	for_each_cpu(i, hctx->cpumask) {
250 		if (first)
251 			ret += sprintf(ret + page, "%u", i);
252 		else
253 			ret += sprintf(ret + page, ", %u", i);
254 
255 		first = 0;
256 	}
257 
258 	ret += sprintf(ret + page, "\n");
259 	return ret;
260 }
261 
262 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
263 	.attr = {.name = "dispatched", .mode = S_IRUGO },
264 	.show = blk_mq_sysfs_dispatched_show,
265 };
266 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
267 	.attr = {.name = "merged", .mode = S_IRUGO },
268 	.show = blk_mq_sysfs_merged_show,
269 };
270 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
271 	.attr = {.name = "completed", .mode = S_IRUGO },
272 	.show = blk_mq_sysfs_completed_show,
273 };
274 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
275 	.attr = {.name = "rq_list", .mode = S_IRUGO },
276 	.show = blk_mq_sysfs_rq_list_show,
277 };
278 
279 static struct attribute *default_ctx_attrs[] = {
280 	&blk_mq_sysfs_dispatched.attr,
281 	&blk_mq_sysfs_merged.attr,
282 	&blk_mq_sysfs_completed.attr,
283 	&blk_mq_sysfs_rq_list.attr,
284 	NULL,
285 };
286 
287 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
288 	.attr = {.name = "queued", .mode = S_IRUGO },
289 	.show = blk_mq_hw_sysfs_queued_show,
290 };
291 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
292 	.attr = {.name = "run", .mode = S_IRUGO },
293 	.show = blk_mq_hw_sysfs_run_show,
294 };
295 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
296 	.attr = {.name = "dispatched", .mode = S_IRUGO },
297 	.show = blk_mq_hw_sysfs_dispatched_show,
298 };
299 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
300 	.attr = {.name = "active", .mode = S_IRUGO },
301 	.show = blk_mq_hw_sysfs_active_show,
302 };
303 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
304 	.attr = {.name = "pending", .mode = S_IRUGO },
305 	.show = blk_mq_hw_sysfs_rq_list_show,
306 };
307 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
308 	.attr = {.name = "tags", .mode = S_IRUGO },
309 	.show = blk_mq_hw_sysfs_tags_show,
310 };
311 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
312 	.attr = {.name = "cpu_list", .mode = S_IRUGO },
313 	.show = blk_mq_hw_sysfs_cpus_show,
314 };
315 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
316 	.attr = {.name = "io_poll", .mode = S_IWUSR | S_IRUGO },
317 	.show = blk_mq_hw_sysfs_poll_show,
318 	.store = blk_mq_hw_sysfs_poll_store,
319 };
320 
321 static struct attribute *default_hw_ctx_attrs[] = {
322 	&blk_mq_hw_sysfs_queued.attr,
323 	&blk_mq_hw_sysfs_run.attr,
324 	&blk_mq_hw_sysfs_dispatched.attr,
325 	&blk_mq_hw_sysfs_pending.attr,
326 	&blk_mq_hw_sysfs_tags.attr,
327 	&blk_mq_hw_sysfs_cpus.attr,
328 	&blk_mq_hw_sysfs_active.attr,
329 	&blk_mq_hw_sysfs_poll.attr,
330 	NULL,
331 };
332 
333 static const struct sysfs_ops blk_mq_sysfs_ops = {
334 	.show	= blk_mq_sysfs_show,
335 	.store	= blk_mq_sysfs_store,
336 };
337 
338 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
339 	.show	= blk_mq_hw_sysfs_show,
340 	.store	= blk_mq_hw_sysfs_store,
341 };
342 
343 static struct kobj_type blk_mq_ktype = {
344 	.sysfs_ops	= &blk_mq_sysfs_ops,
345 	.release	= blk_mq_sysfs_release,
346 };
347 
348 static struct kobj_type blk_mq_ctx_ktype = {
349 	.sysfs_ops	= &blk_mq_sysfs_ops,
350 	.default_attrs	= default_ctx_attrs,
351 	.release	= blk_mq_sysfs_release,
352 };
353 
354 static struct kobj_type blk_mq_hw_ktype = {
355 	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
356 	.default_attrs	= default_hw_ctx_attrs,
357 	.release	= blk_mq_sysfs_release,
358 };
359 
360 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
361 {
362 	struct blk_mq_ctx *ctx;
363 	int i;
364 
365 	if (!hctx->nr_ctx)
366 		return;
367 
368 	hctx_for_each_ctx(hctx, ctx, i)
369 		kobject_del(&ctx->kobj);
370 
371 	kobject_del(&hctx->kobj);
372 }
373 
374 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
375 {
376 	struct request_queue *q = hctx->queue;
377 	struct blk_mq_ctx *ctx;
378 	int i, ret;
379 
380 	if (!hctx->nr_ctx)
381 		return 0;
382 
383 	ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
384 	if (ret)
385 		return ret;
386 
387 	hctx_for_each_ctx(hctx, ctx, i) {
388 		ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
389 		if (ret)
390 			break;
391 	}
392 
393 	return ret;
394 }
395 
396 static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
397 {
398 	struct blk_mq_hw_ctx *hctx;
399 	struct blk_mq_ctx *ctx;
400 	int i, j;
401 
402 	queue_for_each_hw_ctx(q, hctx, i) {
403 		blk_mq_unregister_hctx(hctx);
404 
405 		hctx_for_each_ctx(hctx, ctx, j)
406 			kobject_put(&ctx->kobj);
407 
408 		kobject_put(&hctx->kobj);
409 	}
410 
411 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
412 	kobject_del(&q->mq_kobj);
413 	kobject_put(&q->mq_kobj);
414 
415 	kobject_put(&dev->kobj);
416 
417 	q->mq_sysfs_init_done = false;
418 }
419 
420 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
421 {
422 	blk_mq_disable_hotplug();
423 	__blk_mq_unregister_dev(dev, q);
424 	blk_mq_enable_hotplug();
425 }
426 
427 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
428 {
429 	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
430 }
431 
432 static void blk_mq_sysfs_init(struct request_queue *q)
433 {
434 	struct blk_mq_ctx *ctx;
435 	int cpu;
436 
437 	kobject_init(&q->mq_kobj, &blk_mq_ktype);
438 
439 	for_each_possible_cpu(cpu) {
440 		ctx = per_cpu_ptr(q->queue_ctx, cpu);
441 		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
442 	}
443 }
444 
445 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
446 {
447 	struct blk_mq_hw_ctx *hctx;
448 	int ret, i;
449 
450 	blk_mq_disable_hotplug();
451 
452 	blk_mq_sysfs_init(q);
453 
454 	ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
455 	if (ret < 0)
456 		goto out;
457 
458 	kobject_uevent(&q->mq_kobj, KOBJ_ADD);
459 
460 	queue_for_each_hw_ctx(q, hctx, i) {
461 		ret = blk_mq_register_hctx(hctx);
462 		if (ret)
463 			break;
464 	}
465 
466 	if (ret)
467 		__blk_mq_unregister_dev(dev, q);
468 	else
469 		q->mq_sysfs_init_done = true;
470 out:
471 	blk_mq_enable_hotplug();
472 
473 	return ret;
474 }
475 EXPORT_SYMBOL_GPL(blk_mq_register_dev);
476 
477 void blk_mq_sysfs_unregister(struct request_queue *q)
478 {
479 	struct blk_mq_hw_ctx *hctx;
480 	int i;
481 
482 	if (!q->mq_sysfs_init_done)
483 		return;
484 
485 	queue_for_each_hw_ctx(q, hctx, i)
486 		blk_mq_unregister_hctx(hctx);
487 }
488 
489 int blk_mq_sysfs_register(struct request_queue *q)
490 {
491 	struct blk_mq_hw_ctx *hctx;
492 	int i, ret = 0;
493 
494 	if (!q->mq_sysfs_init_done)
495 		return ret;
496 
497 	queue_for_each_hw_ctx(q, hctx, i) {
498 		ret = blk_mq_register_hctx(hctx);
499 		if (ret)
500 			break;
501 	}
502 
503 	return ret;
504 }
505