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