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         blk_mq_disable_hotplug();
 233
 234         for_each_cpu(i, hctx->cpumask) {
 235                 if (first)
 236                         ret += sprintf(ret + page, "%u", i);
 237                 else
 238                         ret += sprintf(ret + page, ", %u", i);
 239
 240                 first = 0;
 241         }
 242
 243         blk_mq_enable_hotplug();
 244
 245         ret += sprintf(ret + page, "\n");
 246         return ret;
 247 }
 248
 249 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
 250         .attr = {.name = "dispatched", .mode = S_IRUGO },
 251         .show = blk_mq_sysfs_dispatched_show,
 252 };
 253 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
 254         .attr = {.name = "merged", .mode = S_IRUGO },
 255         .show = blk_mq_sysfs_merged_show,
 256 };
 257 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
 258         .attr = {.name = "completed", .mode = S_IRUGO },
 259         .show = blk_mq_sysfs_completed_show,
 260 };
 261 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
 262         .attr = {.name = "rq_list", .mode = S_IRUGO },
 263         .show = blk_mq_sysfs_rq_list_show,
 264 };
 265
 266 static struct attribute *default_ctx_attrs[] = {
 267         &blk_mq_sysfs_dispatched.attr,
 268         &blk_mq_sysfs_merged.attr,
 269         &blk_mq_sysfs_completed.attr,
 270         &blk_mq_sysfs_rq_list.attr,
 271         NULL,
 272 };
 273
 274 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
 275         .attr = {.name = "queued", .mode = S_IRUGO },
 276         .show = blk_mq_hw_sysfs_queued_show,
 277 };
 278 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
 279         .attr = {.name = "run", .mode = S_IRUGO },
 280         .show = blk_mq_hw_sysfs_run_show,
 281 };
 282 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
 283         .attr = {.name = "dispatched", .mode = S_IRUGO },
 284         .show = blk_mq_hw_sysfs_dispatched_show,
 285 };
 286 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
 287         .attr = {.name = "active", .mode = S_IRUGO },
 288         .show = blk_mq_hw_sysfs_active_show,
 289 };
 290 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
 291         .attr = {.name = "pending", .mode = S_IRUGO },
 292         .show = blk_mq_hw_sysfs_rq_list_show,
 293 };
 294 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
 295         .attr = {.name = "tags", .mode = S_IRUGO },
 296         .show = blk_mq_hw_sysfs_tags_show,
 297 };
 298 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 299         .attr = {.name = "cpu_list", .mode = S_IRUGO },
 300         .show = blk_mq_hw_sysfs_cpus_show,
 301 };
 302
 303 static struct attribute *default_hw_ctx_attrs[] = {
 304         &blk_mq_hw_sysfs_queued.attr,
 305         &blk_mq_hw_sysfs_run.attr,
 306         &blk_mq_hw_sysfs_dispatched.attr,
 307         &blk_mq_hw_sysfs_pending.attr,
 308         &blk_mq_hw_sysfs_tags.attr,
 309         &blk_mq_hw_sysfs_cpus.attr,
 310         &blk_mq_hw_sysfs_active.attr,
 311         NULL,
 312 };
 313
 314 static const struct sysfs_ops blk_mq_sysfs_ops = {
 315         .show   = blk_mq_sysfs_show,
 316         .store  = blk_mq_sysfs_store,
 317 };
 318
 319 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 320         .show   = blk_mq_hw_sysfs_show,
 321         .store  = blk_mq_hw_sysfs_store,
 322 };
 323
 324 static struct kobj_type blk_mq_ktype = {
 325         .sysfs_ops      = &blk_mq_sysfs_ops,
 326         .release        = blk_mq_sysfs_release,
 327 };
 328
 329 static struct kobj_type blk_mq_ctx_ktype = {
 330         .sysfs_ops      = &blk_mq_sysfs_ops,
 331         .default_attrs  = default_ctx_attrs,
 332         .release        = blk_mq_sysfs_release,
 333 };
 334
 335 static struct kobj_type blk_mq_hw_ktype = {
 336         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 337         .default_attrs  = default_hw_ctx_attrs,
 338         .release        = blk_mq_sysfs_release,
 339 };
 340
 341 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 342 {
 343         struct blk_mq_ctx *ctx;
 344         int i;
 345
 346         if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
 347                 return;
 348
 349         hctx_for_each_ctx(hctx, ctx, i)
 350                 kobject_del(&ctx->kobj);
 351
 352         kobject_del(&hctx->kobj);
 353 }
 354
 355 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 356 {
 357         struct request_queue *q = hctx->queue;
 358         struct blk_mq_ctx *ctx;
 359         int i, ret;
 360
 361         if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
 362                 return 0;
 363
 364         ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
 365         if (ret)
 366                 return ret;
 367
 368         hctx_for_each_ctx(hctx, ctx, i) {
 369                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 370                 if (ret)
 371                         break;
 372         }
 373
 374         return ret;
 375 }
 376
 377 void blk_mq_unregister_disk(struct gendisk *disk)
 378 {
 379         struct request_queue *q = disk->queue;
 380         struct blk_mq_hw_ctx *hctx;
 381         struct blk_mq_ctx *ctx;
 382         int i, j;
 383
 384         queue_for_each_hw_ctx(q, hctx, i) {
 385                 blk_mq_unregister_hctx(hctx);
 386
 387                 hctx_for_each_ctx(hctx, ctx, j)
 388                         kobject_put(&ctx->kobj);
 389
 390                 kobject_put(&hctx->kobj);
 391         }
 392
 393         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 394         kobject_del(&q->mq_kobj);
 395         kobject_put(&q->mq_kobj);
 396
 397         kobject_put(&disk_to_dev(disk)->kobj);
 398 }
 399
 400 static void blk_mq_sysfs_init(struct request_queue *q)
 401 {
 402         struct blk_mq_hw_ctx *hctx;
 403         struct blk_mq_ctx *ctx;
 404         int i;
 405
 406         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 407
 408         queue_for_each_hw_ctx(q, hctx, i)
 409                 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 410
 411         queue_for_each_ctx(q, ctx, i)
 412                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 413 }
 414
 415 /* see blk_register_queue() */
 416 void blk_mq_finish_init(struct request_queue *q)
 417 {
 418         percpu_ref_switch_to_percpu(&q->mq_usage_counter);
 419 }
 420
 421 int blk_mq_register_disk(struct gendisk *disk)
 422 {
 423         struct device *dev = disk_to_dev(disk);
 424         struct request_queue *q = disk->queue;
 425         struct blk_mq_hw_ctx *hctx;
 426         int ret, i;
 427
 428         blk_mq_sysfs_init(q);
 429
 430         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 431         if (ret < 0)
 432                 return ret;
 433
 434         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 435
 436         queue_for_each_hw_ctx(q, hctx, i) {
 437                 hctx->flags |= BLK_MQ_F_SYSFS_UP;
 438                 ret = blk_mq_register_hctx(hctx);
 439                 if (ret)
 440                         break;
 441         }
 442
 443         if (ret) {
 444                 blk_mq_unregister_disk(disk);
 445                 return ret;
 446         }
 447
 448         return 0;
 449 }
 450 EXPORT_SYMBOL_GPL(blk_mq_register_disk);
 451
 452 void blk_mq_sysfs_unregister(struct request_queue *q)
 453 {
 454         struct blk_mq_hw_ctx *hctx;
 455         int i;
 456
 457         queue_for_each_hw_ctx(q, hctx, i)
 458                 blk_mq_unregister_hctx(hctx);
 459 }
 460
 461 int blk_mq_sysfs_register(struct request_queue *q)
 462 {
 463         struct blk_mq_hw_ctx *hctx;
 464         int i, ret = 0;
 465
 466         queue_for_each_hw_ctx(q, hctx, i) {
 467                 ret = blk_mq_register_hctx(hctx);
 468                 if (ret)
 469                         break;
 470         }
 471
 472         return ret;
 473 }