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