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->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         const size_t size = PAGE_SIZE - 1;
 155         unsigned int i, first = 1;
 156         int ret = 0, pos = 0;
 157
 158         for_each_cpu(i, hctx->cpumask) {
 159                 if (first)
 160                         ret = snprintf(pos + page, size - pos, "%u", i);
 161                 else
 162                         ret = snprintf(pos + page, size - pos, ", %u", i);
 163
 164                 if (ret >= size - pos)
 165                         break;
 166
 167                 first = 0;
 168                 pos += ret;
 169         }
 170
 171         ret = snprintf(pos + page, size + 1 - pos, "\n");
 172         return pos + ret;
 173 }
 174
 175 static struct attribute *default_ctx_attrs[] = {
 176         NULL,
 177 };
 178
 179 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
 180         .attr = {.name = "nr_tags", .mode = 0444 },
 181         .show = blk_mq_hw_sysfs_nr_tags_show,
 182 };
 183 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
 184         .attr = {.name = "nr_reserved_tags", .mode = 0444 },
 185         .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
 186 };
 187 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 188         .attr = {.name = "cpu_list", .mode = 0444 },
 189         .show = blk_mq_hw_sysfs_cpus_show,
 190 };
 191
 192 static struct attribute *default_hw_ctx_attrs[] = {
 193         &blk_mq_hw_sysfs_nr_tags.attr,
 194         &blk_mq_hw_sysfs_nr_reserved_tags.attr,
 195         &blk_mq_hw_sysfs_cpus.attr,
 196         NULL,
 197 };
 198
 199 static const struct sysfs_ops blk_mq_sysfs_ops = {
 200         .show   = blk_mq_sysfs_show,
 201         .store  = blk_mq_sysfs_store,
 202 };
 203
 204 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 205         .show   = blk_mq_hw_sysfs_show,
 206         .store  = blk_mq_hw_sysfs_store,
 207 };
 208
 209 static struct kobj_type blk_mq_ktype = {
 210         .sysfs_ops      = &blk_mq_sysfs_ops,
 211         .release        = blk_mq_sysfs_release,
 212 };
 213
 214 static struct kobj_type blk_mq_ctx_ktype = {
 215         .sysfs_ops      = &blk_mq_sysfs_ops,
 216         .default_attrs  = default_ctx_attrs,
 217         .release        = blk_mq_sysfs_release,
 218 };
 219
 220 static struct kobj_type blk_mq_hw_ktype = {
 221         .sysfs_ops      = &blk_mq_hw_sysfs_ops,
 222         .default_attrs  = default_hw_ctx_attrs,
 223         .release        = blk_mq_hw_sysfs_release,
 224 };
 225
 226 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 227 {
 228         struct blk_mq_ctx *ctx;
 229         int i;
 230
 231         if (!hctx->nr_ctx)
 232                 return;
 233
 234         hctx_for_each_ctx(hctx, ctx, i)
 235                 kobject_del(&ctx->kobj);
 236
 237         kobject_del(&hctx->kobj);
 238 }
 239
 240 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 241 {
 242         struct request_queue *q = hctx->queue;
 243         struct blk_mq_ctx *ctx;
 244         int i, ret;
 245
 246         if (!hctx->nr_ctx)
 247                 return 0;
 248
 249         ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
 250         if (ret)
 251                 return ret;
 252
 253         hctx_for_each_ctx(hctx, ctx, i) {
 254                 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
 255                 if (ret)
 256                         break;
 257         }
 258
 259         return ret;
 260 }
 261
 262 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
 263 {
 264         struct blk_mq_hw_ctx *hctx;
 265         int i;
 266
 267         lockdep_assert_held(&q->sysfs_lock);
 268
 269         queue_for_each_hw_ctx(q, hctx, i)
 270                 blk_mq_unregister_hctx(hctx);
 271
 272         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 273         kobject_del(&q->mq_kobj);
 274         kobject_put(&dev->kobj);
 275
 276         q->mq_sysfs_init_done = false;
 277 }
 278
 279 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 280 {
 281         kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 282 }
 283
 284 void blk_mq_sysfs_deinit(struct request_queue *q)
 285 {
 286         struct blk_mq_ctx *ctx;
 287         int cpu;
 288
 289         for_each_possible_cpu(cpu) {
 290                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 291                 kobject_put(&ctx->kobj);
 292         }
 293         kobject_put(&q->mq_kobj);
 294 }
 295
 296 void blk_mq_sysfs_init(struct request_queue *q)
 297 {
 298         struct blk_mq_ctx *ctx;
 299         int cpu;
 300
 301         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 302
 303         for_each_possible_cpu(cpu) {
 304                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 305                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 306         }
 307 }
 308
 309 int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 310 {
 311         struct blk_mq_hw_ctx *hctx;
 312         int ret, i;
 313
 314         WARN_ON_ONCE(!q->kobj.parent);
 315         lockdep_assert_held(&q->sysfs_lock);
 316
 317         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 318         if (ret < 0)
 319                 goto out;
 320
 321         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 322
 323         queue_for_each_hw_ctx(q, hctx, i) {
 324                 ret = blk_mq_register_hctx(hctx);
 325                 if (ret)
 326                         goto unreg;
 327         }
 328
 329         q->mq_sysfs_init_done = true;
 330
 331 out:
 332         return ret;
 333
 334 unreg:
 335         while (--i >= 0)
 336                 blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
 337
 338         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 339         kobject_del(&q->mq_kobj);
 340         kobject_put(&dev->kobj);
 341         return ret;
 342 }
 343
 344 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
 345 {
 346         int ret;
 347
 348         mutex_lock(&q->sysfs_lock);
 349         ret = __blk_mq_register_dev(dev, q);
 350         mutex_unlock(&q->sysfs_lock);
 351
 352         return ret;
 353 }
 354 EXPORT_SYMBOL_GPL(blk_mq_register_dev);
 355
 356 void blk_mq_sysfs_unregister(struct request_queue *q)
 357 {
 358         struct blk_mq_hw_ctx *hctx;
 359         int i;
 360
 361         mutex_lock(&q->sysfs_lock);
 362         if (!q->mq_sysfs_init_done)
 363                 goto unlock;
 364
 365         queue_for_each_hw_ctx(q, hctx, i)
 366                 blk_mq_unregister_hctx(hctx);
 367
 368 unlock:
 369         mutex_unlock(&q->sysfs_lock);
 370 }
 371
 372 int blk_mq_sysfs_register(struct request_queue *q)
 373 {
 374         struct blk_mq_hw_ctx *hctx;
 375         int i, ret = 0;
 376
 377         mutex_lock(&q->sysfs_lock);
 378         if (!q->mq_sysfs_init_done)
 379                 goto unlock;
 380
 381         queue_for_each_hw_ctx(q, hctx, i) {
 382                 ret = blk_mq_register_hctx(hctx);
 383                 if (ret)
 384                         break;
 385         }
 386
 387 unlock:
 388         mutex_unlock(&q->sysfs_lock);
 389
 390         return ret;
 391 }