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
  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         const size_t size = PAGE_SIZE - 1;
 247         unsigned int i, first = 1;
 248         int ret = 0, pos = 0;
 249
 250         for_each_cpu(i, hctx->cpumask) {
 251                 if (first)
 252                         ret = snprintf(pos + page, size - pos, "%u", i);
 253                 else
 254                         ret = snprintf(pos + page, size - pos, ", %u", i);
 255
 256                 if (ret >= size - pos)
 257                         break;
 258
 259                 first = 0;
 260                 pos += ret;
 261         }
 262
 263         ret = snprintf(pos + page, size + 1 - pos, "\n");
 264         return pos + ret;
 265 }
 266
 267 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
 268         .attr = {.name = "dispatched", .mode = S_IRUGO },
 269         .show = blk_mq_sysfs_dispatched_show,
 270 };
 271 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
 272         .attr = {.name = "merged", .mode = S_IRUGO },
 273         .show = blk_mq_sysfs_merged_show,
 274 };
 275 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
 276         .attr = {.name = "completed", .mode = S_IRUGO },
 277         .show = blk_mq_sysfs_completed_show,
 278 };
 279 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
 280         .attr = {.name = "rq_list", .mode = S_IRUGO },
 281         .show = blk_mq_sysfs_rq_list_show,
 282 };
 283
 284 static struct attribute *default_ctx_attrs[] = {
 285         &blk_mq_sysfs_dispatched.attr,
 286         &blk_mq_sysfs_merged.attr,
 287         &blk_mq_sysfs_completed.attr,
 288         &blk_mq_sysfs_rq_list.attr,
 289         NULL,
 290 };
 291
 292 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
 293         .attr = {.name = "queued", .mode = S_IRUGO },
 294         .show = blk_mq_hw_sysfs_queued_show,
 295 };
 296 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
 297         .attr = {.name = "run", .mode = S_IRUGO },
 298         .show = blk_mq_hw_sysfs_run_show,
 299 };
 300 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
 301         .attr = {.name = "dispatched", .mode = S_IRUGO },
 302         .show = blk_mq_hw_sysfs_dispatched_show,
 303 };
 304 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
 305         .attr = {.name = "active", .mode = S_IRUGO },
 306         .show = blk_mq_hw_sysfs_active_show,
 307 };
 308 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
 309         .attr = {.name = "pending", .mode = S_IRUGO },
 310         .show = blk_mq_hw_sysfs_rq_list_show,
 311 };
 312 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
 313         .attr = {.name = "tags", .mode = S_IRUGO },
 314         .show = blk_mq_hw_sysfs_tags_show,
 315 };
 316 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 317         .attr = {.name = "cpu_list", .mode = S_IRUGO },
 318         .show = blk_mq_hw_sysfs_cpus_show,
 319 };
 320 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
 321         .attr = {.name = "io_poll", .mode = S_IWUSR | S_IRUGO },
 322         .show = blk_mq_hw_sysfs_poll_show,
 323         .store = blk_mq_hw_sysfs_poll_store,
 324 };
 325
 326 static struct attribute *default_hw_ctx_attrs[] = {
 327         &blk_mq_hw_sysfs_queued.attr,
 328         &blk_mq_hw_sysfs_run.attr,
 329         &blk_mq_hw_sysfs_dispatched.attr,
 330         &blk_mq_hw_sysfs_pending.attr,
 331         &blk_mq_hw_sysfs_tags.attr,
 332         &blk_mq_hw_sysfs_cpus.attr,
 333         &blk_mq_hw_sysfs_active.attr,
 334         &blk_mq_hw_sysfs_poll.attr,
 335         NULL,
 336 };
 337
 338 static const struct sysfs_ops blk_mq_sysfs_ops = {
 339         .show   = blk_mq_sysfs_show,
 340         .store  = blk_mq_sysfs_store,
 341 };
 342
 343 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 344         .show   = blk_mq_hw_sysfs_show,
 345         .store  = blk_mq_hw_sysfs_store,
 346 };
 347
 348 static struct kobj_type blk_mq_ktype = {
 349         .sysfs_ops      = &blk_mq_sysfs_ops,
 350         .release        = blk_mq_sysfs_release,
 351 };
 352
 353 static struct kobj_type blk_mq_ctx_ktype = {
 354         .sysfs_ops      = &blk_mq_sysfs_ops,
 355         .default_attrs  = default_ctx_attrs,
 356         .release        = blk_mq_sysfs_release,
 357 };
 358
 359 static struct kobj_type blk_mq_hw_ktype = {
 360         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 361         .default_attrs  = default_hw_ctx_attrs,
 362         .release        = blk_mq_sysfs_release,
 363 };
 364
 365 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 366 {
 367         struct blk_mq_ctx *ctx;
 368         int i;
 369
 370         if (!hctx->nr_ctx)
 371                 return;
 372
 373         hctx_for_each_ctx(hctx, ctx, i)
 374                 kobject_del(&ctx->kobj);
 375
 376         kobject_del(&hctx->kobj);
 377 }
 378
 379 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 380 {
 381         struct request_queue *q = hctx->queue;
 382         struct blk_mq_ctx *ctx;
 383         int i, ret;
 384
 385         if (!hctx->nr_ctx)
 386                 return 0;
 387
 388         ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
 389         if (ret)
 390                 return ret;
 391
 392         hctx_for_each_ctx(hctx, ctx, i) {
 393                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 394                 if (ret)
 395                         break;
 396         }
 397
 398         return ret;
 399 }
 400
 401 static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 402 {
 403         struct blk_mq_hw_ctx *hctx;
 404         struct blk_mq_ctx *ctx;
 405         int i, j;
 406
 407         queue_for_each_hw_ctx(q, hctx, i) {
 408                 blk_mq_unregister_hctx(hctx);
 409
 410                 hctx_for_each_ctx(hctx, ctx, j)
 411                         kobject_put(&ctx->kobj);
 412
 413                 kobject_put(&hctx->kobj);
 414         }
 415
 416         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 417         kobject_del(&q->mq_kobj);
 418         kobject_put(&q->mq_kobj);
 419
 420         kobject_put(&dev->kobj);
 421
 422         q->mq_sysfs_init_done = false;
 423 }
 424
 425 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 426 {
 427         blk_mq_disable_hotplug();
 428         __blk_mq_unregister_dev(dev, q);
 429         blk_mq_enable_hotplug();
 430 }
 431
 432 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 433 {
 434         kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 435 }
 436
 437 void blk_mq_sysfs_init(struct request_queue *q)
 438 {
 439         struct blk_mq_ctx *ctx;
 440         int cpu;
 441
 442         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 443
 444         for_each_possible_cpu(cpu) {
 445                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 446                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 447         }
 448 }
 449
 450 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
 451 {
 452         struct blk_mq_hw_ctx *hctx;
 453         int ret, i;
 454
 455         blk_mq_disable_hotplug();
 456
 457         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 458         if (ret < 0)
 459                 goto out;
 460
 461         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 462
 463         queue_for_each_hw_ctx(q, hctx, i) {
 464                 ret = blk_mq_register_hctx(hctx);
 465                 if (ret)
 466                         break;
 467         }
 468
 469         if (ret)
 470                 __blk_mq_unregister_dev(dev, q);
 471         else
 472                 q->mq_sysfs_init_done = true;
 473 out:
 474         blk_mq_enable_hotplug();
 475
 476         return ret;
 477 }
 478 EXPORT_SYMBOL_GPL(blk_mq_register_dev);
 479
 480 void blk_mq_sysfs_unregister(struct request_queue *q)
 481 {
 482         struct blk_mq_hw_ctx *hctx;
 483         int i;
 484
 485         if (!q->mq_sysfs_init_done)
 486                 return;
 487
 488         queue_for_each_hw_ctx(q, hctx, i)
 489                 blk_mq_unregister_hctx(hctx);
 490 }
 491
 492 int blk_mq_sysfs_register(struct request_queue *q)
 493 {
 494         struct blk_mq_hw_ctx *hctx;
 495         int i, ret = 0;
 496
 497         if (!q->mq_sysfs_init_done)
 498                 return ret;
 499
 500         queue_for_each_hw_ctx(q, hctx, i) {
 501                 ret = blk_mq_register_hctx(hctx);
 502                 if (ret)
 503                         break;
 504         }
 505
 506         return ret;
 507 }