block/blk-mq-debugfs.c

   1 /*
   2  * Copyright (C) 2017 Facebook
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/debugfs.h>
  20
  21 #include <linux/blk-mq.h>
  22 #include "blk.h"
  23 #include "blk-mq.h"
  24 #include "blk-mq-tag.h"
  25
  26 struct blk_mq_debugfs_attr {
  27         const char *name;
  28         umode_t mode;
  29         const struct file_operations *fops;
  30 };
  31
  32 static int blk_mq_debugfs_seq_open(struct inode *inode, struct file *file,
  33                                    const struct seq_operations *ops)
  34 {
  35         struct seq_file *m;
  36         int ret;
  37
  38         ret = seq_open(file, ops);
  39         if (!ret) {
  40                 m = file->private_data;
  41                 m->private = inode->i_private;
  42         }
  43         return ret;
  44 }
  45
  46 static int hctx_state_show(struct seq_file *m, void *v)
  47 {
  48         struct blk_mq_hw_ctx *hctx = m->private;
  49
  50         seq_printf(m, "0x%lx\n", hctx->state);
  51         return 0;
  52 }
  53
  54 static int hctx_state_open(struct inode *inode, struct file *file)
  55 {
  56         return single_open(file, hctx_state_show, inode->i_private);
  57 }
  58
  59 static const struct file_operations hctx_state_fops = {
  60         .open           = hctx_state_open,
  61         .read           = seq_read,
  62         .llseek         = seq_lseek,
  63         .release        = single_release,
  64 };
  65
  66 static int hctx_flags_show(struct seq_file *m, void *v)
  67 {
  68         struct blk_mq_hw_ctx *hctx = m->private;
  69
  70         seq_printf(m, "0x%lx\n", hctx->flags);
  71         return 0;
  72 }
  73
  74 static int hctx_flags_open(struct inode *inode, struct file *file)
  75 {
  76         return single_open(file, hctx_flags_show, inode->i_private);
  77 }
  78
  79 static const struct file_operations hctx_flags_fops = {
  80         .open           = hctx_flags_open,
  81         .read           = seq_read,
  82         .llseek         = seq_lseek,
  83         .release        = single_release,
  84 };
  85
  86 static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
  87 {
  88         struct request *rq = list_entry_rq(v);
  89
  90         seq_printf(m, "%p {.cmd_flags=0x%x, .rq_flags=0x%x, .tag=%d, .internal_tag=%d}\n",
  91                    rq, rq->cmd_flags, (__force unsigned int)rq->rq_flags,
  92                    rq->tag, rq->internal_tag);
  93         return 0;
  94 }
  95
  96 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
  97         __acquires(&hctx->lock)
  98 {
  99         struct blk_mq_hw_ctx *hctx = m->private;
 100
 101         spin_lock(&hctx->lock);
 102         return seq_list_start(&hctx->dispatch, *pos);
 103 }
 104
 105 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 106 {
 107         struct blk_mq_hw_ctx *hctx = m->private;
 108
 109         return seq_list_next(v, &hctx->dispatch, pos);
 110 }
 111
 112 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 113         __releases(&hctx->lock)
 114 {
 115         struct blk_mq_hw_ctx *hctx = m->private;
 116
 117         spin_unlock(&hctx->lock);
 118 }
 119
 120 static const struct seq_operations hctx_dispatch_seq_ops = {
 121         .start  = hctx_dispatch_start,
 122         .next   = hctx_dispatch_next,
 123         .stop   = hctx_dispatch_stop,
 124         .show   = blk_mq_debugfs_rq_show,
 125 };
 126
 127 static int hctx_dispatch_open(struct inode *inode, struct file *file)
 128 {
 129         return blk_mq_debugfs_seq_open(inode, file, &hctx_dispatch_seq_ops);
 130 }
 131
 132 static const struct file_operations hctx_dispatch_fops = {
 133         .open           = hctx_dispatch_open,
 134         .read           = seq_read,
 135         .llseek         = seq_lseek,
 136         .release        = seq_release,
 137 };
 138
 139 static int hctx_ctx_map_show(struct seq_file *m, void *v)
 140 {
 141         struct blk_mq_hw_ctx *hctx = m->private;
 142
 143         sbitmap_bitmap_show(&hctx->ctx_map, m);
 144         return 0;
 145 }
 146
 147 static int hctx_ctx_map_open(struct inode *inode, struct file *file)
 148 {
 149         return single_open(file, hctx_ctx_map_show, inode->i_private);
 150 }
 151
 152 static const struct file_operations hctx_ctx_map_fops = {
 153         .open           = hctx_ctx_map_open,
 154         .read           = seq_read,
 155         .llseek         = seq_lseek,
 156         .release        = single_release,
 157 };
 158
 159 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 160                                      struct blk_mq_tags *tags)
 161 {
 162         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 163         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 164         seq_printf(m, "active_queues=%d\n",
 165                    atomic_read(&tags->active_queues));
 166
 167         seq_puts(m, "\nbitmap_tags:\n");
 168         sbitmap_queue_show(&tags->bitmap_tags, m);
 169
 170         if (tags->nr_reserved_tags) {
 171                 seq_puts(m, "\nbreserved_tags:\n");
 172                 sbitmap_queue_show(&tags->breserved_tags, m);
 173         }
 174 }
 175
 176 static int hctx_tags_show(struct seq_file *m, void *v)
 177 {
 178         struct blk_mq_hw_ctx *hctx = m->private;
 179         struct request_queue *q = hctx->queue;
 180         int res;
 181
 182         res = mutex_lock_interruptible(&q->sysfs_lock);
 183         if (res)
 184                 goto out;
 185         if (hctx->tags)
 186                 blk_mq_debugfs_tags_show(m, hctx->tags);
 187         mutex_unlock(&q->sysfs_lock);
 188
 189 out:
 190         return res;
 191 }
 192
 193 static int hctx_tags_open(struct inode *inode, struct file *file)
 194 {
 195         return single_open(file, hctx_tags_show, inode->i_private);
 196 }
 197
 198 static const struct file_operations hctx_tags_fops = {
 199         .open           = hctx_tags_open,
 200         .read           = seq_read,
 201         .llseek         = seq_lseek,
 202         .release        = single_release,
 203 };
 204
 205 static int hctx_tags_bitmap_show(struct seq_file *m, void *v)
 206 {
 207         struct blk_mq_hw_ctx *hctx = m->private;
 208         struct request_queue *q = hctx->queue;
 209         int res;
 210
 211         res = mutex_lock_interruptible(&q->sysfs_lock);
 212         if (res)
 213                 goto out;
 214         if (hctx->tags)
 215                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 216         mutex_unlock(&q->sysfs_lock);
 217
 218 out:
 219         return res;
 220 }
 221
 222 static int hctx_tags_bitmap_open(struct inode *inode, struct file *file)
 223 {
 224         return single_open(file, hctx_tags_bitmap_show, inode->i_private);
 225 }
 226
 227 static const struct file_operations hctx_tags_bitmap_fops = {
 228         .open           = hctx_tags_bitmap_open,
 229         .read           = seq_read,
 230         .llseek         = seq_lseek,
 231         .release        = single_release,
 232 };
 233
 234 static int hctx_sched_tags_show(struct seq_file *m, void *v)
 235 {
 236         struct blk_mq_hw_ctx *hctx = m->private;
 237         struct request_queue *q = hctx->queue;
 238         int res;
 239
 240         res = mutex_lock_interruptible(&q->sysfs_lock);
 241         if (res)
 242                 goto out;
 243         if (hctx->sched_tags)
 244                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 245         mutex_unlock(&q->sysfs_lock);
 246
 247 out:
 248         return res;
 249 }
 250
 251 static int hctx_sched_tags_open(struct inode *inode, struct file *file)
 252 {
 253         return single_open(file, hctx_sched_tags_show, inode->i_private);
 254 }
 255
 256 static const struct file_operations hctx_sched_tags_fops = {
 257         .open           = hctx_sched_tags_open,
 258         .read           = seq_read,
 259         .llseek         = seq_lseek,
 260         .release        = single_release,
 261 };
 262
 263 static int hctx_sched_tags_bitmap_show(struct seq_file *m, void *v)
 264 {
 265         struct blk_mq_hw_ctx *hctx = m->private;
 266         struct request_queue *q = hctx->queue;
 267         int res;
 268
 269         res = mutex_lock_interruptible(&q->sysfs_lock);
 270         if (res)
 271                 goto out;
 272         if (hctx->sched_tags)
 273                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 274         mutex_unlock(&q->sysfs_lock);
 275
 276 out:
 277         return res;
 278 }
 279
 280 static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file)
 281 {
 282         return single_open(file, hctx_sched_tags_bitmap_show, inode->i_private);
 283 }
 284
 285 static const struct file_operations hctx_sched_tags_bitmap_fops = {
 286         .open           = hctx_sched_tags_bitmap_open,
 287         .read           = seq_read,
 288         .llseek         = seq_lseek,
 289         .release        = single_release,
 290 };
 291
 292 static int hctx_io_poll_show(struct seq_file *m, void *v)
 293 {
 294         struct blk_mq_hw_ctx *hctx = m->private;
 295
 296         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 297         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 298         seq_printf(m, "success=%lu\n", hctx->poll_success);
 299         return 0;
 300 }
 301
 302 static int hctx_io_poll_open(struct inode *inode, struct file *file)
 303 {
 304         return single_open(file, hctx_io_poll_show, inode->i_private);
 305 }
 306
 307 static ssize_t hctx_io_poll_write(struct file *file, const char __user *buf,
 308                                   size_t count, loff_t *ppos)
 309 {
 310         struct seq_file *m = file->private_data;
 311         struct blk_mq_hw_ctx *hctx = m->private;
 312
 313         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 314         return count;
 315 }
 316
 317 static const struct file_operations hctx_io_poll_fops = {
 318         .open           = hctx_io_poll_open,
 319         .read           = seq_read,
 320         .write          = hctx_io_poll_write,
 321         .llseek         = seq_lseek,
 322         .release        = single_release,
 323 };
 324
 325 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
 326 {
 327         seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
 328                    stat->nr_samples, stat->mean, stat->min, stat->max);
 329 }
 330
 331 static int hctx_stats_show(struct seq_file *m, void *v)
 332 {
 333         struct blk_mq_hw_ctx *hctx = m->private;
 334         struct blk_rq_stat stat[2];
 335
 336         blk_stat_init(&stat[BLK_STAT_READ]);
 337         blk_stat_init(&stat[BLK_STAT_WRITE]);
 338
 339         blk_hctx_stat_get(hctx, stat);
 340
 341         seq_puts(m, "read: ");
 342         print_stat(m, &stat[BLK_STAT_READ]);
 343         seq_puts(m, "\n");
 344
 345         seq_puts(m, "write: ");
 346         print_stat(m, &stat[BLK_STAT_WRITE]);
 347         seq_puts(m, "\n");
 348         return 0;
 349 }
 350
 351 static int hctx_stats_open(struct inode *inode, struct file *file)
 352 {
 353         return single_open(file, hctx_stats_show, inode->i_private);
 354 }
 355
 356 static ssize_t hctx_stats_write(struct file *file, const char __user *buf,
 357                                 size_t count, loff_t *ppos)
 358 {
 359         struct seq_file *m = file->private_data;
 360         struct blk_mq_hw_ctx *hctx = m->private;
 361         struct blk_mq_ctx *ctx;
 362         int i;
 363
 364         hctx_for_each_ctx(hctx, ctx, i) {
 365                 blk_stat_init(&ctx->stat[BLK_STAT_READ]);
 366                 blk_stat_init(&ctx->stat[BLK_STAT_WRITE]);
 367         }
 368         return count;
 369 }
 370
 371 static const struct file_operations hctx_stats_fops = {
 372         .open           = hctx_stats_open,
 373         .read           = seq_read,
 374         .write          = hctx_stats_write,
 375         .llseek         = seq_lseek,
 376         .release        = single_release,
 377 };
 378
 379 static int hctx_dispatched_show(struct seq_file *m, void *v)
 380 {
 381         struct blk_mq_hw_ctx *hctx = m->private;
 382         int i;
 383
 384         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 385
 386         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 387                 unsigned int d = 1U << (i - 1);
 388
 389                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 390         }
 391
 392         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 393         return 0;
 394 }
 395
 396 static int hctx_dispatched_open(struct inode *inode, struct file *file)
 397 {
 398         return single_open(file, hctx_dispatched_show, inode->i_private);
 399 }
 400
 401 static ssize_t hctx_dispatched_write(struct file *file, const char __user *buf,
 402                                      size_t count, loff_t *ppos)
 403 {
 404         struct seq_file *m = file->private_data;
 405         struct blk_mq_hw_ctx *hctx = m->private;
 406         int i;
 407
 408         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 409                 hctx->dispatched[i] = 0;
 410         return count;
 411 }
 412
 413 static const struct file_operations hctx_dispatched_fops = {
 414         .open           = hctx_dispatched_open,
 415         .read           = seq_read,
 416         .write          = hctx_dispatched_write,
 417         .llseek         = seq_lseek,
 418         .release        = single_release,
 419 };
 420
 421 static int hctx_queued_show(struct seq_file *m, void *v)
 422 {
 423         struct blk_mq_hw_ctx *hctx = m->private;
 424
 425         seq_printf(m, "%lu\n", hctx->queued);
 426         return 0;
 427 }
 428
 429 static int hctx_queued_open(struct inode *inode, struct file *file)
 430 {
 431         return single_open(file, hctx_queued_show, inode->i_private);
 432 }
 433
 434 static ssize_t hctx_queued_write(struct file *file, const char __user *buf,
 435                                  size_t count, loff_t *ppos)
 436 {
 437         struct seq_file *m = file->private_data;
 438         struct blk_mq_hw_ctx *hctx = m->private;
 439
 440         hctx->queued = 0;
 441         return count;
 442 }
 443
 444 static const struct file_operations hctx_queued_fops = {
 445         .open           = hctx_queued_open,
 446         .read           = seq_read,
 447         .write          = hctx_queued_write,
 448         .llseek         = seq_lseek,
 449         .release        = single_release,
 450 };
 451
 452 static int hctx_run_show(struct seq_file *m, void *v)
 453 {
 454         struct blk_mq_hw_ctx *hctx = m->private;
 455
 456         seq_printf(m, "%lu\n", hctx->run);
 457         return 0;
 458 }
 459
 460 static int hctx_run_open(struct inode *inode, struct file *file)
 461 {
 462         return single_open(file, hctx_run_show, inode->i_private);
 463 }
 464
 465 static ssize_t hctx_run_write(struct file *file, const char __user *buf,
 466                                  size_t count, loff_t *ppos)
 467 {
 468         struct seq_file *m = file->private_data;
 469         struct blk_mq_hw_ctx *hctx = m->private;
 470
 471         hctx->run = 0;
 472         return count;
 473 }
 474
 475 static const struct file_operations hctx_run_fops = {
 476         .open           = hctx_run_open,
 477         .read           = seq_read,
 478         .write          = hctx_run_write,
 479         .llseek         = seq_lseek,
 480         .release        = single_release,
 481 };
 482
 483 static int hctx_active_show(struct seq_file *m, void *v)
 484 {
 485         struct blk_mq_hw_ctx *hctx = m->private;
 486
 487         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 488         return 0;
 489 }
 490
 491 static int hctx_active_open(struct inode *inode, struct file *file)
 492 {
 493         return single_open(file, hctx_active_show, inode->i_private);
 494 }
 495
 496 static const struct file_operations hctx_active_fops = {
 497         .open           = hctx_active_open,
 498         .read           = seq_read,
 499         .llseek         = seq_lseek,
 500         .release        = single_release,
 501 };
 502
 503 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 504         __acquires(&ctx->lock)
 505 {
 506         struct blk_mq_ctx *ctx = m->private;
 507
 508         spin_lock(&ctx->lock);
 509         return seq_list_start(&ctx->rq_list, *pos);
 510 }
 511
 512 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
 513 {
 514         struct blk_mq_ctx *ctx = m->private;
 515
 516         return seq_list_next(v, &ctx->rq_list, pos);
 517 }
 518
 519 static void ctx_rq_list_stop(struct seq_file *m, void *v)
 520         __releases(&ctx->lock)
 521 {
 522         struct blk_mq_ctx *ctx = m->private;
 523
 524         spin_unlock(&ctx->lock);
 525 }
 526
 527 static const struct seq_operations ctx_rq_list_seq_ops = {
 528         .start  = ctx_rq_list_start,
 529         .next   = ctx_rq_list_next,
 530         .stop   = ctx_rq_list_stop,
 531         .show   = blk_mq_debugfs_rq_show,
 532 };
 533
 534 static int ctx_rq_list_open(struct inode *inode, struct file *file)
 535 {
 536         return blk_mq_debugfs_seq_open(inode, file, &ctx_rq_list_seq_ops);
 537 }
 538
 539 static const struct file_operations ctx_rq_list_fops = {
 540         .open           = ctx_rq_list_open,
 541         .read           = seq_read,
 542         .llseek         = seq_lseek,
 543         .release        = seq_release,
 544 };
 545
 546 static int ctx_dispatched_show(struct seq_file *m, void *v)
 547 {
 548         struct blk_mq_ctx *ctx = m->private;
 549
 550         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 551         return 0;
 552 }
 553
 554 static int ctx_dispatched_open(struct inode *inode, struct file *file)
 555 {
 556         return single_open(file, ctx_dispatched_show, inode->i_private);
 557 }
 558
 559 static ssize_t ctx_dispatched_write(struct file *file, const char __user *buf,
 560                                     size_t count, loff_t *ppos)
 561 {
 562         struct seq_file *m = file->private_data;
 563         struct blk_mq_ctx *ctx = m->private;
 564
 565         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 566         return count;
 567 }
 568
 569 static const struct file_operations ctx_dispatched_fops = {
 570         .open           = ctx_dispatched_open,
 571         .read           = seq_read,
 572         .write          = ctx_dispatched_write,
 573         .llseek         = seq_lseek,
 574         .release        = single_release,
 575 };
 576
 577 static int ctx_merged_show(struct seq_file *m, void *v)
 578 {
 579         struct blk_mq_ctx *ctx = m->private;
 580
 581         seq_printf(m, "%lu\n", ctx->rq_merged);
 582         return 0;
 583 }
 584
 585 static int ctx_merged_open(struct inode *inode, struct file *file)
 586 {
 587         return single_open(file, ctx_merged_show, inode->i_private);
 588 }
 589
 590 static ssize_t ctx_merged_write(struct file *file, const char __user *buf,
 591                                     size_t count, loff_t *ppos)
 592 {
 593         struct seq_file *m = file->private_data;
 594         struct blk_mq_ctx *ctx = m->private;
 595
 596         ctx->rq_merged = 0;
 597         return count;
 598 }
 599
 600 static const struct file_operations ctx_merged_fops = {
 601         .open           = ctx_merged_open,
 602         .read           = seq_read,
 603         .write          = ctx_merged_write,
 604         .llseek         = seq_lseek,
 605         .release        = single_release,
 606 };
 607
 608 static int ctx_completed_show(struct seq_file *m, void *v)
 609 {
 610         struct blk_mq_ctx *ctx = m->private;
 611
 612         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 613         return 0;
 614 }
 615
 616 static int ctx_completed_open(struct inode *inode, struct file *file)
 617 {
 618         return single_open(file, ctx_completed_show, inode->i_private);
 619 }
 620
 621 static ssize_t ctx_completed_write(struct file *file, const char __user *buf,
 622                                    size_t count, loff_t *ppos)
 623 {
 624         struct seq_file *m = file->private_data;
 625         struct blk_mq_ctx *ctx = m->private;
 626
 627         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 628         return count;
 629 }
 630
 631 static const struct file_operations ctx_completed_fops = {
 632         .open           = ctx_completed_open,
 633         .read           = seq_read,
 634         .write          = ctx_completed_write,
 635         .llseek         = seq_lseek,
 636         .release        = single_release,
 637 };
 638
 639 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 640         {"state", 0400, &hctx_state_fops},
 641         {"flags", 0400, &hctx_flags_fops},
 642         {"dispatch", 0400, &hctx_dispatch_fops},
 643         {"ctx_map", 0400, &hctx_ctx_map_fops},
 644         {"tags", 0400, &hctx_tags_fops},
 645         {"tags_bitmap", 0400, &hctx_tags_bitmap_fops},
 646         {"sched_tags", 0400, &hctx_sched_tags_fops},
 647         {"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops},
 648         {"io_poll", 0600, &hctx_io_poll_fops},
 649         {"stats", 0600, &hctx_stats_fops},
 650         {"dispatched", 0600, &hctx_dispatched_fops},
 651         {"queued", 0600, &hctx_queued_fops},
 652         {"run", 0600, &hctx_run_fops},
 653         {"active", 0400, &hctx_active_fops},
 654         {},
 655 };
 656
 657 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 658         {"rq_list", 0400, &ctx_rq_list_fops},
 659         {"dispatched", 0600, &ctx_dispatched_fops},
 660         {"merged", 0600, &ctx_merged_fops},
 661         {"completed", 0600, &ctx_completed_fops},
 662         {},
 663 };
 664
 665 int blk_mq_debugfs_register(struct request_queue *q, const char *name)
 666 {
 667         if (!blk_debugfs_root)
 668                 return -ENOENT;
 669
 670         q->debugfs_dir = debugfs_create_dir(name, blk_debugfs_root);
 671         if (!q->debugfs_dir)
 672                 goto err;
 673
 674         if (blk_mq_debugfs_register_hctxs(q))
 675                 goto err;
 676
 677         return 0;
 678
 679 err:
 680         blk_mq_debugfs_unregister(q);
 681         return -ENOMEM;
 682 }
 683
 684 void blk_mq_debugfs_unregister(struct request_queue *q)
 685 {
 686         debugfs_remove_recursive(q->debugfs_dir);
 687         q->mq_debugfs_dir = NULL;
 688         q->debugfs_dir = NULL;
 689 }
 690
 691 static bool debugfs_create_files(struct dentry *parent, void *data,
 692                                 const struct blk_mq_debugfs_attr *attr)
 693 {
 694         for (; attr->name; attr++) {
 695                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 696                                          data, attr->fops))
 697                         return false;
 698         }
 699         return true;
 700 }
 701
 702 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
 703                                        struct blk_mq_ctx *ctx,
 704                                        struct dentry *hctx_dir)
 705 {
 706         struct dentry *ctx_dir;
 707         char name[20];
 708
 709         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 710         ctx_dir = debugfs_create_dir(name, hctx_dir);
 711         if (!ctx_dir)
 712                 return -ENOMEM;
 713
 714         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 715                 return -ENOMEM;
 716
 717         return 0;
 718 }
 719
 720 static int blk_mq_debugfs_register_hctx(struct request_queue *q,
 721                                         struct blk_mq_hw_ctx *hctx)
 722 {
 723         struct blk_mq_ctx *ctx;
 724         struct dentry *hctx_dir;
 725         char name[20];
 726         int i;
 727
 728         snprintf(name, sizeof(name), "%u", hctx->queue_num);
 729         hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
 730         if (!hctx_dir)
 731                 return -ENOMEM;
 732
 733         if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
 734                 return -ENOMEM;
 735
 736         hctx_for_each_ctx(hctx, ctx, i) {
 737                 if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
 738                         return -ENOMEM;
 739         }
 740
 741         return 0;
 742 }
 743
 744 int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 745 {
 746         struct blk_mq_hw_ctx *hctx;
 747         int i;
 748
 749         if (!q->debugfs_dir)
 750                 return -ENOENT;
 751
 752         q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
 753         if (!q->mq_debugfs_dir)
 754                 goto err;
 755
 756         queue_for_each_hw_ctx(q, hctx, i) {
 757                 if (blk_mq_debugfs_register_hctx(q, hctx))
 758                         goto err;
 759         }
 760
 761         return 0;
 762
 763 err:
 764         blk_mq_debugfs_unregister_hctxs(q);
 765         return -ENOMEM;
 766 }
 767
 768 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 769 {
 770         debugfs_remove_recursive(q->mq_debugfs_dir);
 771         q->mq_debugfs_dir = NULL;
 772 }