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