block/blk-mq-sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kernel.h>
   3 #include <linux/module.h>
   4 #include <linux/backing-dev.h>
   5 #include <linux/bio.h>
   6 #include <linux/blkdev.h>
   7 #include <linux/mm.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/smp.h>
  12
  13 #include <linux/blk-mq.h>
  14 #include "blk.h"
  15 #include "blk-mq.h"
  16 #include "blk-mq-tag.h"
  17
  18 static void blk_mq_sysfs_release(struct kobject *kobj)
  19 {
  20         struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
  21
  22         free_percpu(ctxs->queue_ctx);
  23         kfree(ctxs);
  24 }
  25
  26 static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
  27 {
  28         struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
  29
  30         /* ctx->ctxs won't be released until all ctx are freed */
  31         kobject_put(&ctx->ctxs->kobj);
  32 }
  33
  34 static void blk_mq_hw_sysfs_release(struct kobject *kobj)
  35 {
  36         struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
  37                                                   kobj);
  38
  39         cancel_delayed_work_sync(&hctx->run_work);
  40
  41         if (hctx->flags & BLK_MQ_F_BLOCKING)
  42                 cleanup_srcu_struct(hctx->srcu);
  43         blk_free_flush_queue(hctx->fq);
  44         sbitmap_free(&hctx->ctx_map);
  45         free_cpumask_var(hctx->cpumask);
  46         kfree(hctx->ctxs);
  47         kfree(hctx);
  48 }
  49
  50 struct blk_mq_ctx_sysfs_entry {
  51         struct attribute attr;
  52         ssize_t (*show)(struct blk_mq_ctx *, char *);
  53         ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
  54 };
  55
  56 struct blk_mq_hw_ctx_sysfs_entry {
  57         struct attribute attr;
  58         ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
  59         ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
  60 };
  61
  62 static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
  63                                  char *page)
  64 {
  65         struct blk_mq_ctx_sysfs_entry *entry;
  66         struct blk_mq_ctx *ctx;
  67         struct request_queue *q;
  68         ssize_t res;
  69
  70         entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
  71         ctx = container_of(kobj, struct blk_mq_ctx, kobj);
  72         q = ctx->queue;
  73
  74         if (!entry->show)
  75                 return -EIO;
  76
  77         res = -ENOENT;
  78         mutex_lock(&q->sysfs_lock);
  79         if (!blk_queue_dying(q))
  80                 res = entry->show(ctx, page);
  81         mutex_unlock(&q->sysfs_lock);
  82         return res;
  83 }
  84
  85 static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
  86                                   const char *page, size_t length)
  87 {
  88         struct blk_mq_ctx_sysfs_entry *entry;
  89         struct blk_mq_ctx *ctx;
  90         struct request_queue *q;
  91         ssize_t res;
  92
  93         entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
  94         ctx = container_of(kobj, struct blk_mq_ctx, kobj);
  95         q = ctx->queue;
  96
  97         if (!entry->store)
  98                 return -EIO;
  99
 100         res = -ENOENT;
 101         mutex_lock(&q->sysfs_lock);
 102         if (!blk_queue_dying(q))
 103                 res = entry->store(ctx, page, length);
 104         mutex_unlock(&q->sysfs_lock);
 105         return res;
 106 }
 107
 108 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
 109                                     struct attribute *attr, char *page)
 110 {
 111         struct blk_mq_hw_ctx_sysfs_entry *entry;
 112         struct blk_mq_hw_ctx *hctx;
 113         struct request_queue *q;
 114         ssize_t res;
 115
 116         entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
 117         hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
 118         q = hctx->queue;
 119
 120         if (!entry->show)
 121                 return -EIO;
 122
 123         res = -ENOENT;
 124         mutex_lock(&q->sysfs_lock);
 125         if (!blk_queue_dying(q))
 126                 res = entry->show(hctx, page);
 127         mutex_unlock(&q->sysfs_lock);
 128         return res;
 129 }
 130
 131 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
 132                                      struct attribute *attr, const char *page,
 133                                      size_t length)
 134 {
 135         struct blk_mq_hw_ctx_sysfs_entry *entry;
 136         struct blk_mq_hw_ctx *hctx;
 137         struct request_queue *q;
 138         ssize_t res;
 139
 140         entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
 141         hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
 142         q = hctx->queue;
 143
 144         if (!entry->store)
 145                 return -EIO;
 146
 147         res = -ENOENT;
 148         mutex_lock(&q->sysfs_lock);
 149         if (!blk_queue_dying(q))
 150                 res = entry->store(hctx, page, length);
 151         mutex_unlock(&q->sysfs_lock);
 152         return res;
 153 }
 154
 155 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
 156                                             char *page)
 157 {
 158         return sprintf(page, "%u\n", hctx->tags->nr_tags);
 159 }
 160
 161 static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
 162                                                      char *page)
 163 {
 164         return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
 165 }
 166
 167 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
 168 {
 169         unsigned int i, first = 1;
 170         ssize_t ret = 0;
 171
 172         for_each_cpu(i, hctx->cpumask) {
 173                 if (first)
 174                         ret += sprintf(ret + page, "%u", i);
 175                 else
 176                         ret += sprintf(ret + page, ", %u", i);
 177
 178                 first = 0;
 179         }
 180
 181         ret += sprintf(ret + page, "\n");
 182         return ret;
 183 }
 184
 185 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
 186         .attr = {.name = "nr_tags", .mode = 0444 },
 187         .show = blk_mq_hw_sysfs_nr_tags_show,
 188 };
 189 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
 190         .attr = {.name = "nr_reserved_tags", .mode = 0444 },
 191         .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
 192 };
 193 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 194         .attr = {.name = "cpu_list", .mode = 0444 },
 195         .show = blk_mq_hw_sysfs_cpus_show,
 196 };
 197
 198 static struct attribute *default_hw_ctx_attrs[] = {
 199         &blk_mq_hw_sysfs_nr_tags.attr,
 200         &blk_mq_hw_sysfs_nr_reserved_tags.attr,
 201         &blk_mq_hw_sysfs_cpus.attr,
 202         NULL,
 203 };
 204 ATTRIBUTE_GROUPS(default_hw_ctx);
 205
 206 static const struct sysfs_ops blk_mq_sysfs_ops = {
 207         .show   = blk_mq_sysfs_show,
 208         .store  = blk_mq_sysfs_store,
 209 };
 210
 211 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 212         .show   = blk_mq_hw_sysfs_show,
 213         .store  = blk_mq_hw_sysfs_store,
 214 };
 215
 216 static struct kobj_type blk_mq_ktype = {
 217         .sysfs_ops      = &blk_mq_sysfs_ops,
 218         .release        = blk_mq_sysfs_release,
 219 };
 220
 221 static struct kobj_type blk_mq_ctx_ktype = {
 222         .sysfs_ops      = &blk_mq_sysfs_ops,
 223         .release        = blk_mq_ctx_sysfs_release,
 224 };
 225
 226 static struct kobj_type blk_mq_hw_ktype = {
 227         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 228         .default_groups = default_hw_ctx_groups,
 229         .release        = blk_mq_hw_sysfs_release,
 230 };
 231
 232 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 233 {
 234         struct blk_mq_ctx *ctx;
 235         int i;
 236
 237         if (!hctx->nr_ctx)
 238                 return;
 239
 240         hctx_for_each_ctx(hctx, ctx, i)
 241                 kobject_del(&ctx->kobj);
 242
 243         kobject_del(&hctx->kobj);
 244 }
 245
 246 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 247 {
 248         struct request_queue *q = hctx->queue;
 249         struct blk_mq_ctx *ctx;
 250         int i, ret;
 251
 252         if (!hctx->nr_ctx)
 253                 return 0;
 254
 255         ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
 256         if (ret)
 257                 return ret;
 258
 259         hctx_for_each_ctx(hctx, ctx, i) {
 260                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 261                 if (ret)
 262                         break;
 263         }
 264
 265         return ret;
 266 }
 267
 268 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 269 {
 270         struct blk_mq_hw_ctx *hctx;
 271         int i;
 272
 273         lockdep_assert_held(&q->sysfs_lock);
 274
 275         queue_for_each_hw_ctx(q, hctx, i)
 276                 blk_mq_unregister_hctx(hctx);
 277
 278         kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
 279         kobject_del(q->mq_kobj);
 280         kobject_put(&dev->kobj);
 281
 282         q->mq_sysfs_init_done = false;
 283 }
 284
 285 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 286 {
 287         kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 288 }
 289
 290 void blk_mq_sysfs_deinit(struct request_queue *q)
 291 {
 292         struct blk_mq_ctx *ctx;
 293         int cpu;
 294
 295         for_each_possible_cpu(cpu) {
 296                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 297                 kobject_put(&ctx->kobj);
 298         }
 299         kobject_put(q->mq_kobj);
 300 }
 301
 302 void blk_mq_sysfs_init(struct request_queue *q)
 303 {
 304         struct blk_mq_ctx *ctx;
 305         int cpu;
 306
 307         kobject_init(q->mq_kobj, &blk_mq_ktype);
 308
 309         for_each_possible_cpu(cpu) {
 310                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 311
 312                 kobject_get(q->mq_kobj);
 313                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 314         }
 315 }
 316
 317 int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 318 {
 319         struct blk_mq_hw_ctx *hctx;
 320         int ret, i;
 321
 322         WARN_ON_ONCE(!q->kobj.parent);
 323         lockdep_assert_held(&q->sysfs_lock);
 324
 325         ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 326         if (ret < 0)
 327                 goto out;
 328
 329         kobject_uevent(q->mq_kobj, KOBJ_ADD);
 330
 331         queue_for_each_hw_ctx(q, hctx, i) {
 332                 ret = blk_mq_register_hctx(hctx);
 333                 if (ret)
 334                         goto unreg;
 335         }
 336
 337         q->mq_sysfs_init_done = true;
 338
 339 out:
 340         return ret;
 341
 342 unreg:
 343         while (--i >= 0)
 344                 blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
 345
 346         kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
 347         kobject_del(q->mq_kobj);
 348         kobject_put(&dev->kobj);
 349         return ret;
 350 }
 351
 352 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
 353 {
 354         int ret;
 355
 356         mutex_lock(&q->sysfs_lock);
 357         ret = __blk_mq_register_dev(dev, q);
 358         mutex_unlock(&q->sysfs_lock);
 359
 360         return ret;
 361 }
 362
 363 void blk_mq_sysfs_unregister(struct request_queue *q)
 364 {
 365         struct blk_mq_hw_ctx *hctx;
 366         int i;
 367
 368         mutex_lock(&q->sysfs_lock);
 369         if (!q->mq_sysfs_init_done)
 370                 goto unlock;
 371
 372         queue_for_each_hw_ctx(q, hctx, i)
 373                 blk_mq_unregister_hctx(hctx);
 374
 375 unlock:
 376         mutex_unlock(&q->sysfs_lock);
 377 }
 378
 379 int blk_mq_sysfs_register(struct request_queue *q)
 380 {
 381         struct blk_mq_hw_ctx *hctx;
 382         int i, ret = 0;
 383
 384         mutex_lock(&q->sysfs_lock);
 385         if (!q->mq_sysfs_init_done)
 386                 goto unlock;
 387
 388         queue_for_each_hw_ctx(q, hctx, i) {
 389                 ret = blk_mq_register_hctx(hctx);
 390                 if (ret)
 391                         break;
 392         }
 393
 394 unlock:
 395         mutex_unlock(&q->sysfs_lock);
 396
 397         return ret;
 398 }