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         char *start_page = page;
 145         struct request *rq;
 146
 147         page += sprintf(page, "%s:\n", msg);
 148
 149         list_for_each_entry(rq, list, queuelist)
 150                 page += sprintf(page, "\t%p\n", rq);
 151
 152         return page - start_page;
 153 }
 154
 155 static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)
 156 {
 157         ssize_t ret;
 158
 159         spin_lock(&ctx->lock);
 160         ret = sysfs_list_show(page, &ctx->rq_list, "CTX pending");
 161         spin_unlock(&ctx->lock);
 162
 163         return ret;
 164 }
 165
 166 static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
 167                                            char *page)
 168 {
 169         return sprintf(page, "%lu\n", hctx->queued);
 170 }
 171
 172 static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
 173 {
 174         return sprintf(page, "%lu\n", hctx->run);
 175 }
 176
 177 static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
 178                                                char *page)
 179 {
 180         char *start_page = page;
 181         int i;
 182
 183         page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 184
 185         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
 186                 unsigned long d = 1U << (i - 1);
 187
 188                 page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
 189         }
 190
 191         return page - start_page;
 192 }
 193
 194 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
 195                                             char *page)
 196 {
 197         ssize_t ret;
 198
 199         spin_lock(&hctx->lock);
 200         ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
 201         spin_unlock(&hctx->lock);
 202
 203         return ret;
 204 }
 205
 206 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
 207 {
 208         return blk_mq_tag_sysfs_show(hctx->tags, page);
 209 }
 210
 211 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
 212 {
 213         return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
 214 }
 215
 216 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
 217 {
 218         unsigned int i, first = 1;
 219         ssize_t ret = 0;
 220
 221         blk_mq_disable_hotplug();
 222
 223         for_each_cpu(i, hctx->cpumask) {
 224                 if (first)
 225                         ret += sprintf(ret + page, "%u", i);
 226                 else
 227                         ret += sprintf(ret + page, ", %u", i);
 228
 229                 first = 0;
 230         }
 231
 232         blk_mq_enable_hotplug();
 233
 234         ret += sprintf(ret + page, "\n");
 235         return ret;
 236 }
 237
 238 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
 239         .attr = {.name = "dispatched", .mode = S_IRUGO },
 240         .show = blk_mq_sysfs_dispatched_show,
 241 };
 242 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
 243         .attr = {.name = "merged", .mode = S_IRUGO },
 244         .show = blk_mq_sysfs_merged_show,
 245 };
 246 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
 247         .attr = {.name = "completed", .mode = S_IRUGO },
 248         .show = blk_mq_sysfs_completed_show,
 249 };
 250 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
 251         .attr = {.name = "rq_list", .mode = S_IRUGO },
 252         .show = blk_mq_sysfs_rq_list_show,
 253 };
 254
 255 static struct attribute *default_ctx_attrs[] = {
 256         &blk_mq_sysfs_dispatched.attr,
 257         &blk_mq_sysfs_merged.attr,
 258         &blk_mq_sysfs_completed.attr,
 259         &blk_mq_sysfs_rq_list.attr,
 260         NULL,
 261 };
 262
 263 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
 264         .attr = {.name = "queued", .mode = S_IRUGO },
 265         .show = blk_mq_hw_sysfs_queued_show,
 266 };
 267 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
 268         .attr = {.name = "run", .mode = S_IRUGO },
 269         .show = blk_mq_hw_sysfs_run_show,
 270 };
 271 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
 272         .attr = {.name = "dispatched", .mode = S_IRUGO },
 273         .show = blk_mq_hw_sysfs_dispatched_show,
 274 };
 275 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
 276         .attr = {.name = "active", .mode = S_IRUGO },
 277         .show = blk_mq_hw_sysfs_active_show,
 278 };
 279 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
 280         .attr = {.name = "pending", .mode = S_IRUGO },
 281         .show = blk_mq_hw_sysfs_rq_list_show,
 282 };
 283 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
 284         .attr = {.name = "tags", .mode = S_IRUGO },
 285         .show = blk_mq_hw_sysfs_tags_show,
 286 };
 287 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 288         .attr = {.name = "cpu_list", .mode = S_IRUGO },
 289         .show = blk_mq_hw_sysfs_cpus_show,
 290 };
 291
 292 static struct attribute *default_hw_ctx_attrs[] = {
 293         &blk_mq_hw_sysfs_queued.attr,
 294         &blk_mq_hw_sysfs_run.attr,
 295         &blk_mq_hw_sysfs_dispatched.attr,
 296         &blk_mq_hw_sysfs_pending.attr,
 297         &blk_mq_hw_sysfs_tags.attr,
 298         &blk_mq_hw_sysfs_cpus.attr,
 299         &blk_mq_hw_sysfs_active.attr,
 300         NULL,
 301 };
 302
 303 static const struct sysfs_ops blk_mq_sysfs_ops = {
 304         .show   = blk_mq_sysfs_show,
 305         .store  = blk_mq_sysfs_store,
 306 };
 307
 308 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 309         .show   = blk_mq_hw_sysfs_show,
 310         .store  = blk_mq_hw_sysfs_store,
 311 };
 312
 313 static struct kobj_type blk_mq_ktype = {
 314         .sysfs_ops      = &blk_mq_sysfs_ops,
 315         .release        = blk_mq_sysfs_release,
 316 };
 317
 318 static struct kobj_type blk_mq_ctx_ktype = {
 319         .sysfs_ops      = &blk_mq_sysfs_ops,
 320         .default_attrs  = default_ctx_attrs,
 321         .release        = blk_mq_sysfs_release,
 322 };
 323
 324 static struct kobj_type blk_mq_hw_ktype = {
 325         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 326         .default_attrs  = default_hw_ctx_attrs,
 327         .release        = blk_mq_sysfs_release,
 328 };
 329
 330 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 331 {
 332         struct blk_mq_ctx *ctx;
 333         int i;
 334
 335         if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
 336                 return;
 337
 338         hctx_for_each_ctx(hctx, ctx, i)
 339                 kobject_del(&ctx->kobj);
 340
 341         kobject_del(&hctx->kobj);
 342 }
 343
 344 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 345 {
 346         struct request_queue *q = hctx->queue;
 347         struct blk_mq_ctx *ctx;
 348         int i, ret;
 349
 350         if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
 351                 return 0;
 352
 353         ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
 354         if (ret)
 355                 return ret;
 356
 357         hctx_for_each_ctx(hctx, ctx, i) {
 358                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 359                 if (ret)
 360                         break;
 361         }
 362
 363         return ret;
 364 }
 365
 366 void blk_mq_unregister_disk(struct gendisk *disk)
 367 {
 368         struct request_queue *q = disk->queue;
 369         struct blk_mq_hw_ctx *hctx;
 370         struct blk_mq_ctx *ctx;
 371         int i, j;
 372
 373         queue_for_each_hw_ctx(q, hctx, i) {
 374                 blk_mq_unregister_hctx(hctx);
 375
 376                 hctx_for_each_ctx(hctx, ctx, j)
 377                         kobject_put(&ctx->kobj);
 378
 379                 kobject_put(&hctx->kobj);
 380         }
 381
 382         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 383         kobject_del(&q->mq_kobj);
 384         kobject_put(&q->mq_kobj);
 385
 386         kobject_put(&disk_to_dev(disk)->kobj);
 387 }
 388
 389 static void blk_mq_sysfs_init(struct request_queue *q)
 390 {
 391         struct blk_mq_hw_ctx *hctx;
 392         struct blk_mq_ctx *ctx;
 393         int i;
 394
 395         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 396
 397         queue_for_each_hw_ctx(q, hctx, i)
 398                 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 399
 400         queue_for_each_ctx(q, ctx, i)
 401                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 402 }
 403
 404 /* see blk_register_queue() */
 405 void blk_mq_finish_init(struct request_queue *q)
 406 {
 407         percpu_ref_switch_to_percpu(&q->mq_usage_counter);
 408 }
 409
 410 int blk_mq_register_disk(struct gendisk *disk)
 411 {
 412         struct device *dev = disk_to_dev(disk);
 413         struct request_queue *q = disk->queue;
 414         struct blk_mq_hw_ctx *hctx;
 415         int ret, i;
 416
 417         blk_mq_sysfs_init(q);
 418
 419         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 420         if (ret < 0)
 421                 return ret;
 422
 423         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 424
 425         queue_for_each_hw_ctx(q, hctx, i) {
 426                 hctx->flags |= BLK_MQ_F_SYSFS_UP;
 427                 ret = blk_mq_register_hctx(hctx);
 428                 if (ret)
 429                         break;
 430         }
 431
 432         if (ret) {
 433                 blk_mq_unregister_disk(disk);
 434                 return ret;
 435         }
 436
 437         return 0;
 438 }
 439
 440 void blk_mq_sysfs_unregister(struct request_queue *q)
 441 {
 442         struct blk_mq_hw_ctx *hctx;
 443         int i;
 444
 445         queue_for_each_hw_ctx(q, hctx, i)
 446                 blk_mq_unregister_hctx(hctx);
 447 }
 448
 449 int blk_mq_sysfs_register(struct request_queue *q)
 450 {
 451         struct blk_mq_hw_ctx *hctx;
 452         int i, ret = 0;
 453
 454         queue_for_each_hw_ctx(q, hctx, i) {
 455                 ret = blk_mq_register_hctx(hctx);
 456                 if (ret)
 457                         break;
 458         }
 459
 460         return ret;
 461 }