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; i++) {
 212                 unsigned long d = 1U << (i - 1);
 213
 214                 page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
 215         }
 216
 217         return page - start_page;
 218 }
 219
 220 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
 221                                             char *page)
 222 {
 223         ssize_t ret;
 224
 225         spin_lock(&hctx->lock);
 226         ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
 227         spin_unlock(&hctx->lock);
 228
 229         return ret;
 230 }
 231
 232 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
 233 {
 234         return blk_mq_tag_sysfs_show(hctx->tags, page);
 235 }
 236
 237 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
 238 {
 239         return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
 240 }
 241
 242 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
 243 {
 244         unsigned int i, first = 1;
 245         ssize_t ret = 0;
 246
 247         for_each_cpu(i, hctx->cpumask) {
 248                 if (first)
 249                         ret += sprintf(ret + page, "%u", i);
 250                 else
 251                         ret += sprintf(ret + page, ", %u", i);
 252
 253                 first = 0;
 254         }
 255
 256         ret += sprintf(ret + page, "\n");
 257         return ret;
 258 }
 259
 260 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
 261         .attr = {.name = "dispatched", .mode = S_IRUGO },
 262         .show = blk_mq_sysfs_dispatched_show,
 263 };
 264 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
 265         .attr = {.name = "merged", .mode = S_IRUGO },
 266         .show = blk_mq_sysfs_merged_show,
 267 };
 268 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
 269         .attr = {.name = "completed", .mode = S_IRUGO },
 270         .show = blk_mq_sysfs_completed_show,
 271 };
 272 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
 273         .attr = {.name = "rq_list", .mode = S_IRUGO },
 274         .show = blk_mq_sysfs_rq_list_show,
 275 };
 276
 277 static struct attribute *default_ctx_attrs[] = {
 278         &blk_mq_sysfs_dispatched.attr,
 279         &blk_mq_sysfs_merged.attr,
 280         &blk_mq_sysfs_completed.attr,
 281         &blk_mq_sysfs_rq_list.attr,
 282         NULL,
 283 };
 284
 285 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
 286         .attr = {.name = "queued", .mode = S_IRUGO },
 287         .show = blk_mq_hw_sysfs_queued_show,
 288 };
 289 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
 290         .attr = {.name = "run", .mode = S_IRUGO },
 291         .show = blk_mq_hw_sysfs_run_show,
 292 };
 293 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
 294         .attr = {.name = "dispatched", .mode = S_IRUGO },
 295         .show = blk_mq_hw_sysfs_dispatched_show,
 296 };
 297 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
 298         .attr = {.name = "active", .mode = S_IRUGO },
 299         .show = blk_mq_hw_sysfs_active_show,
 300 };
 301 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
 302         .attr = {.name = "pending", .mode = S_IRUGO },
 303         .show = blk_mq_hw_sysfs_rq_list_show,
 304 };
 305 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
 306         .attr = {.name = "tags", .mode = S_IRUGO },
 307         .show = blk_mq_hw_sysfs_tags_show,
 308 };
 309 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 310         .attr = {.name = "cpu_list", .mode = S_IRUGO },
 311         .show = blk_mq_hw_sysfs_cpus_show,
 312 };
 313 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
 314         .attr = {.name = "io_poll", .mode = S_IWUSR | S_IRUGO },
 315         .show = blk_mq_hw_sysfs_poll_show,
 316         .store = blk_mq_hw_sysfs_poll_store,
 317 };
 318
 319 static struct attribute *default_hw_ctx_attrs[] = {
 320         &blk_mq_hw_sysfs_queued.attr,
 321         &blk_mq_hw_sysfs_run.attr,
 322         &blk_mq_hw_sysfs_dispatched.attr,
 323         &blk_mq_hw_sysfs_pending.attr,
 324         &blk_mq_hw_sysfs_tags.attr,
 325         &blk_mq_hw_sysfs_cpus.attr,
 326         &blk_mq_hw_sysfs_active.attr,
 327         &blk_mq_hw_sysfs_poll.attr,
 328         NULL,
 329 };
 330
 331 static const struct sysfs_ops blk_mq_sysfs_ops = {
 332         .show   = blk_mq_sysfs_show,
 333         .store  = blk_mq_sysfs_store,
 334 };
 335
 336 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 337         .show   = blk_mq_hw_sysfs_show,
 338         .store  = blk_mq_hw_sysfs_store,
 339 };
 340
 341 static struct kobj_type blk_mq_ktype = {
 342         .sysfs_ops      = &blk_mq_sysfs_ops,
 343         .release        = blk_mq_sysfs_release,
 344 };
 345
 346 static struct kobj_type blk_mq_ctx_ktype = {
 347         .sysfs_ops      = &blk_mq_sysfs_ops,
 348         .default_attrs  = default_ctx_attrs,
 349         .release        = blk_mq_sysfs_release,
 350 };
 351
 352 static struct kobj_type blk_mq_hw_ktype = {
 353         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 354         .default_attrs  = default_hw_ctx_attrs,
 355         .release        = blk_mq_sysfs_release,
 356 };
 357
 358 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 359 {
 360         struct blk_mq_ctx *ctx;
 361         int i;
 362
 363         if (!hctx->nr_ctx)
 364                 return;
 365
 366         hctx_for_each_ctx(hctx, ctx, i)
 367                 kobject_del(&ctx->kobj);
 368
 369         kobject_del(&hctx->kobj);
 370 }
 371
 372 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 373 {
 374         struct request_queue *q = hctx->queue;
 375         struct blk_mq_ctx *ctx;
 376         int i, ret;
 377
 378         if (!hctx->nr_ctx)
 379                 return 0;
 380
 381         ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
 382         if (ret)
 383                 return ret;
 384
 385         hctx_for_each_ctx(hctx, ctx, i) {
 386                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 387                 if (ret)
 388                         break;
 389         }
 390
 391         return ret;
 392 }
 393
 394 static void __blk_mq_unregister_disk(struct gendisk *disk)
 395 {
 396         struct request_queue *q = disk->queue;
 397         struct blk_mq_hw_ctx *hctx;
 398         struct blk_mq_ctx *ctx;
 399         int i, j;
 400
 401         queue_for_each_hw_ctx(q, hctx, i) {
 402                 blk_mq_unregister_hctx(hctx);
 403
 404                 hctx_for_each_ctx(hctx, ctx, j)
 405                         kobject_put(&ctx->kobj);
 406
 407                 kobject_put(&hctx->kobj);
 408         }
 409
 410         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 411         kobject_del(&q->mq_kobj);
 412         kobject_put(&q->mq_kobj);
 413
 414         kobject_put(&disk_to_dev(disk)->kobj);
 415
 416         q->mq_sysfs_init_done = false;
 417 }
 418
 419 void blk_mq_unregister_disk(struct gendisk *disk)
 420 {
 421         blk_mq_disable_hotplug();
 422         __blk_mq_unregister_disk(disk);
 423         blk_mq_enable_hotplug();
 424 }
 425
 426 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 427 {
 428         kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 429 }
 430
 431 static void blk_mq_sysfs_init(struct request_queue *q)
 432 {
 433         struct blk_mq_ctx *ctx;
 434         int cpu;
 435
 436         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 437
 438         for_each_possible_cpu(cpu) {
 439                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 440                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 441         }
 442 }
 443
 444 int blk_mq_register_disk(struct gendisk *disk)
 445 {
 446         struct device *dev = disk_to_dev(disk);
 447         struct request_queue *q = disk->queue;
 448         struct blk_mq_hw_ctx *hctx;
 449         int ret, i;
 450
 451         blk_mq_disable_hotplug();
 452
 453         blk_mq_sysfs_init(q);
 454
 455         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 456         if (ret < 0)
 457                 goto out;
 458
 459         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 460
 461         queue_for_each_hw_ctx(q, hctx, i) {
 462                 ret = blk_mq_register_hctx(hctx);
 463                 if (ret)
 464                         break;
 465         }
 466
 467         if (ret)
 468                 __blk_mq_unregister_disk(disk);
 469         else
 470                 q->mq_sysfs_init_done = true;
 471 out:
 472         blk_mq_enable_hotplug();
 473
 474         return ret;
 475 }
 476 EXPORT_SYMBOL_GPL(blk_mq_register_disk);
 477
 478 void blk_mq_sysfs_unregister(struct request_queue *q)
 479 {
 480         struct blk_mq_hw_ctx *hctx;
 481         int i;
 482
 483         if (!q->mq_sysfs_init_done)
 484                 return;
 485
 486         queue_for_each_hw_ctx(q, hctx, i)
 487                 blk_mq_unregister_hctx(hctx);
 488 }
 489
 490 int blk_mq_sysfs_register(struct request_queue *q)
 491 {
 492         struct blk_mq_hw_ctx *hctx;
 493         int i, ret = 0;
 494
 495         if (!q->mq_sysfs_init_done)
 496                 return ret;
 497
 498         queue_for_each_hw_ctx(q, hctx, i) {
 499                 ret = blk_mq_register_hctx(hctx);
 500                 if (ret)
 501                         break;
 502         }
 503
 504         return ret;
 505 }