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_queued_show(struct blk_mq_hw_ctx *hctx,
 178                                            char *page)
 179 {
 180         return sprintf(page, "%lu\n", hctx->queued);
 181 }
 182
 183 static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
 184 {
 185         return sprintf(page, "%lu\n", hctx->run);
 186 }
 187
 188 static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
 189                                                char *page)
 190 {
 191         char *start_page = page;
 192         int i;
 193
 194         page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 195
 196         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
 197                 unsigned long d = 1U << (i - 1);
 198
 199                 page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
 200         }
 201
 202         return page - start_page;
 203 }
 204
 205 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
 206                                             char *page)
 207 {
 208         ssize_t ret;
 209
 210         spin_lock(&hctx->lock);
 211         ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
 212         spin_unlock(&hctx->lock);
 213
 214         return ret;
 215 }
 216
 217 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
 218 {
 219         return blk_mq_tag_sysfs_show(hctx->tags, page);
 220 }
 221
 222 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
 223 {
 224         return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
 225 }
 226
 227 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
 228 {
 229         unsigned int i, first = 1;
 230         ssize_t ret = 0;
 231
 232         for_each_cpu(i, hctx->cpumask) {
 233                 if (first)
 234                         ret += sprintf(ret + page, "%u", i);
 235                 else
 236                         ret += sprintf(ret + page, ", %u", i);
 237
 238                 first = 0;
 239         }
 240
 241         ret += sprintf(ret + page, "\n");
 242         return ret;
 243 }
 244
 245 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
 246         .attr = {.name = "dispatched", .mode = S_IRUGO },
 247         .show = blk_mq_sysfs_dispatched_show,
 248 };
 249 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
 250         .attr = {.name = "merged", .mode = S_IRUGO },
 251         .show = blk_mq_sysfs_merged_show,
 252 };
 253 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
 254         .attr = {.name = "completed", .mode = S_IRUGO },
 255         .show = blk_mq_sysfs_completed_show,
 256 };
 257 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
 258         .attr = {.name = "rq_list", .mode = S_IRUGO },
 259         .show = blk_mq_sysfs_rq_list_show,
 260 };
 261
 262 static struct attribute *default_ctx_attrs[] = {
 263         &blk_mq_sysfs_dispatched.attr,
 264         &blk_mq_sysfs_merged.attr,
 265         &blk_mq_sysfs_completed.attr,
 266         &blk_mq_sysfs_rq_list.attr,
 267         NULL,
 268 };
 269
 270 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
 271         .attr = {.name = "queued", .mode = S_IRUGO },
 272         .show = blk_mq_hw_sysfs_queued_show,
 273 };
 274 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
 275         .attr = {.name = "run", .mode = S_IRUGO },
 276         .show = blk_mq_hw_sysfs_run_show,
 277 };
 278 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
 279         .attr = {.name = "dispatched", .mode = S_IRUGO },
 280         .show = blk_mq_hw_sysfs_dispatched_show,
 281 };
 282 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
 283         .attr = {.name = "active", .mode = S_IRUGO },
 284         .show = blk_mq_hw_sysfs_active_show,
 285 };
 286 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
 287         .attr = {.name = "pending", .mode = S_IRUGO },
 288         .show = blk_mq_hw_sysfs_rq_list_show,
 289 };
 290 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
 291         .attr = {.name = "tags", .mode = S_IRUGO },
 292         .show = blk_mq_hw_sysfs_tags_show,
 293 };
 294 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 295         .attr = {.name = "cpu_list", .mode = S_IRUGO },
 296         .show = blk_mq_hw_sysfs_cpus_show,
 297 };
 298
 299 static struct attribute *default_hw_ctx_attrs[] = {
 300         &blk_mq_hw_sysfs_queued.attr,
 301         &blk_mq_hw_sysfs_run.attr,
 302         &blk_mq_hw_sysfs_dispatched.attr,
 303         &blk_mq_hw_sysfs_pending.attr,
 304         &blk_mq_hw_sysfs_tags.attr,
 305         &blk_mq_hw_sysfs_cpus.attr,
 306         &blk_mq_hw_sysfs_active.attr,
 307         NULL,
 308 };
 309
 310 static const struct sysfs_ops blk_mq_sysfs_ops = {
 311         .show   = blk_mq_sysfs_show,
 312         .store  = blk_mq_sysfs_store,
 313 };
 314
 315 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 316         .show   = blk_mq_hw_sysfs_show,
 317         .store  = blk_mq_hw_sysfs_store,
 318 };
 319
 320 static struct kobj_type blk_mq_ktype = {
 321         .sysfs_ops      = &blk_mq_sysfs_ops,
 322         .release        = blk_mq_sysfs_release,
 323 };
 324
 325 static struct kobj_type blk_mq_ctx_ktype = {
 326         .sysfs_ops      = &blk_mq_sysfs_ops,
 327         .default_attrs  = default_ctx_attrs,
 328         .release        = blk_mq_sysfs_release,
 329 };
 330
 331 static struct kobj_type blk_mq_hw_ktype = {
 332         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 333         .default_attrs  = default_hw_ctx_attrs,
 334         .release        = blk_mq_sysfs_release,
 335 };
 336
 337 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 338 {
 339         struct blk_mq_ctx *ctx;
 340         int i;
 341
 342         if (!hctx->nr_ctx)
 343                 return;
 344
 345         hctx_for_each_ctx(hctx, ctx, i)
 346                 kobject_del(&ctx->kobj);
 347
 348         kobject_del(&hctx->kobj);
 349 }
 350
 351 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 352 {
 353         struct request_queue *q = hctx->queue;
 354         struct blk_mq_ctx *ctx;
 355         int i, ret;
 356
 357         if (!hctx->nr_ctx)
 358                 return 0;
 359
 360         ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
 361         if (ret)
 362                 return ret;
 363
 364         hctx_for_each_ctx(hctx, ctx, i) {
 365                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 366                 if (ret)
 367                         break;
 368         }
 369
 370         return ret;
 371 }
 372
 373 void blk_mq_unregister_disk(struct gendisk *disk)
 374 {
 375         struct request_queue *q = disk->queue;
 376         struct blk_mq_hw_ctx *hctx;
 377         struct blk_mq_ctx *ctx;
 378         int i, j;
 379
 380         blk_mq_disable_hotplug();
 381
 382         queue_for_each_hw_ctx(q, hctx, i) {
 383                 blk_mq_unregister_hctx(hctx);
 384
 385                 hctx_for_each_ctx(hctx, ctx, j)
 386                         kobject_put(&ctx->kobj);
 387
 388                 kobject_put(&hctx->kobj);
 389         }
 390
 391         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 392         kobject_del(&q->mq_kobj);
 393         kobject_put(&q->mq_kobj);
 394
 395         kobject_put(&disk_to_dev(disk)->kobj);
 396
 397         q->mq_sysfs_init_done = false;
 398         blk_mq_enable_hotplug();
 399 }
 400
 401 static void blk_mq_sysfs_init(struct request_queue *q)
 402 {
 403         struct blk_mq_hw_ctx *hctx;
 404         struct blk_mq_ctx *ctx;
 405         int i;
 406
 407         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 408
 409         queue_for_each_hw_ctx(q, hctx, i)
 410                 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 411
 412         queue_for_each_ctx(q, ctx, i)
 413                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 414 }
 415
 416 /* see blk_register_queue() */
 417 void blk_mq_finish_init(struct request_queue *q)
 418 {
 419         percpu_ref_switch_to_percpu(&q->mq_usage_counter);
 420 }
 421
 422 int blk_mq_register_disk(struct gendisk *disk)
 423 {
 424         struct device *dev = disk_to_dev(disk);
 425         struct request_queue *q = disk->queue;
 426         struct blk_mq_hw_ctx *hctx;
 427         int ret, i;
 428
 429         blk_mq_disable_hotplug();
 430
 431         blk_mq_sysfs_init(q);
 432
 433         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 434         if (ret < 0)
 435                 goto out;
 436
 437         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 438
 439         queue_for_each_hw_ctx(q, hctx, i) {
 440                 ret = blk_mq_register_hctx(hctx);
 441                 if (ret)
 442                         break;
 443         }
 444
 445         if (ret)
 446                 blk_mq_unregister_disk(disk);
 447         else
 448                 q->mq_sysfs_init_done = true;
 449 out:
 450         blk_mq_enable_hotplug();
 451
 452         return ret;
 453 }
 454 EXPORT_SYMBOL_GPL(blk_mq_register_disk);
 455
 456 void blk_mq_sysfs_unregister(struct request_queue *q)
 457 {
 458         struct blk_mq_hw_ctx *hctx;
 459         int i;
 460
 461         if (!q->mq_sysfs_init_done)
 462                 return;
 463
 464         queue_for_each_hw_ctx(q, hctx, i)
 465                 blk_mq_unregister_hctx(hctx);
 466 }
 467
 468 int blk_mq_sysfs_register(struct request_queue *q)
 469 {
 470         struct blk_mq_hw_ctx *hctx;
 471         int i, ret = 0;
 472
 473         if (!q->mq_sysfs_init_done)
 474                 return ret;
 475
 476         queue_for_each_hw_ctx(q, hctx, i) {
 477                 ret = blk_mq_register_hctx(hctx);
 478                 if (ret)
 479                         break;
 480         }
 481
 482         return ret;
 483 }