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         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 = S_IRUGO },
 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 = S_IRUGO },
 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 = S_IRUGO },
 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 static 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_unregister_dev(struct device *dev, struct request_queue *q)
 280 {
 281         mutex_lock(&q->sysfs_lock);
 282         __blk_mq_unregister_dev(dev, q);
 283         mutex_unlock(&q->sysfs_lock);
 284 }
 285
 286 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 287 {
 288         kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 289 }
 290
 291 void blk_mq_sysfs_deinit(struct request_queue *q)
 292 {
 293         struct blk_mq_ctx *ctx;
 294         int cpu;
 295
 296         for_each_possible_cpu(cpu) {
 297                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 298                 kobject_put(&ctx->kobj);
 299         }
 300         kobject_put(&q->mq_kobj);
 301 }
 302
 303 void blk_mq_sysfs_init(struct request_queue *q)
 304 {
 305         struct blk_mq_ctx *ctx;
 306         int cpu;
 307
 308         kobject_init(&q->mq_kobj, &blk_mq_ktype);
 309
 310         for_each_possible_cpu(cpu) {
 311                 ctx = per_cpu_ptr(q->queue_ctx, cpu);
 312                 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 313         }
 314 }
 315
 316 int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 317 {
 318         struct blk_mq_hw_ctx *hctx;
 319         int ret, i;
 320
 321         WARN_ON_ONCE(!q->kobj.parent);
 322         lockdep_assert_held(&q->sysfs_lock);
 323
 324         ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 325         if (ret < 0)
 326                 goto out;
 327
 328         kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 329
 330         queue_for_each_hw_ctx(q, hctx, i) {
 331                 ret = blk_mq_register_hctx(hctx);
 332                 if (ret)
 333                         goto unreg;
 334         }
 335
 336         q->mq_sysfs_init_done = true;
 337
 338 out:
 339         return ret;
 340
 341 unreg:
 342         while (--i >= 0)
 343                 blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
 344
 345         kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
 346         kobject_del(&q->mq_kobj);
 347         kobject_put(&dev->kobj);
 348         return ret;
 349 }
 350
 351 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
 352 {
 353         int ret;
 354
 355         mutex_lock(&q->sysfs_lock);
 356         ret = __blk_mq_register_dev(dev, q);
 357         mutex_unlock(&q->sysfs_lock);
 358
 359         return ret;
 360 }
 361 EXPORT_SYMBOL_GPL(blk_mq_register_dev);
 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 }