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