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 blk_flags_show(struct seq_file *m, const unsigned long flags,
  47                           const char *const *flag_name, int flag_name_count)
  48 {
  49         bool sep = false;
  50         int i;
  51
  52         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  53                 if (!(flags & BIT(i)))
  54                         continue;
  55                 if (sep)
  56                         seq_puts(m, "|");
  57                 sep = true;
  58                 if (i < flag_name_count && flag_name[i])
  59                         seq_puts(m, flag_name[i]);
  60                 else
  61                         seq_printf(m, "%d", i);
  62         }
  63         return 0;
  64 }
  65
  66 static const char *const blk_queue_flag_name[] = {
  67         [QUEUE_FLAG_QUEUED]      = "QUEUED",
  68         [QUEUE_FLAG_STOPPED]     = "STOPPED",
  69         [QUEUE_FLAG_SYNCFULL]    = "SYNCFULL",
  70         [QUEUE_FLAG_ASYNCFULL]   = "ASYNCFULL",
  71         [QUEUE_FLAG_DYING]       = "DYING",
  72         [QUEUE_FLAG_BYPASS]      = "BYPASS",
  73         [QUEUE_FLAG_BIDI]        = "BIDI",
  74         [QUEUE_FLAG_NOMERGES]    = "NOMERGES",
  75         [QUEUE_FLAG_SAME_COMP]   = "SAME_COMP",
  76         [QUEUE_FLAG_FAIL_IO]     = "FAIL_IO",
  77         [QUEUE_FLAG_STACKABLE]   = "STACKABLE",
  78         [QUEUE_FLAG_NONROT]      = "NONROT",
  79         [QUEUE_FLAG_IO_STAT]     = "IO_STAT",
  80         [QUEUE_FLAG_DISCARD]     = "DISCARD",
  81         [QUEUE_FLAG_NOXMERGES]   = "NOXMERGES",
  82         [QUEUE_FLAG_ADD_RANDOM]  = "ADD_RANDOM",
  83         [QUEUE_FLAG_SECERASE]    = "SECERASE",
  84         [QUEUE_FLAG_SAME_FORCE]  = "SAME_FORCE",
  85         [QUEUE_FLAG_DEAD]        = "DEAD",
  86         [QUEUE_FLAG_INIT_DONE]   = "INIT_DONE",
  87         [QUEUE_FLAG_NO_SG_MERGE] = "NO_SG_MERGE",
  88         [QUEUE_FLAG_POLL]        = "POLL",
  89         [QUEUE_FLAG_WC]          = "WC",
  90         [QUEUE_FLAG_FUA]         = "FUA",
  91         [QUEUE_FLAG_FLUSH_NQ]    = "FLUSH_NQ",
  92         [QUEUE_FLAG_DAX]         = "DAX",
  93         [QUEUE_FLAG_STATS]       = "STATS",
  94         [QUEUE_FLAG_POLL_STATS]  = "POLL_STATS",
  95         [QUEUE_FLAG_REGISTERED]  = "REGISTERED",
  96 };
  97
  98 static int blk_queue_flags_show(struct seq_file *m, void *v)
  99 {
 100         struct request_queue *q = m->private;
 101
 102         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 103                        ARRAY_SIZE(blk_queue_flag_name));
 104         seq_puts(m, "\n");
 105         return 0;
 106 }
 107
 108 static ssize_t blk_queue_flags_store(struct file *file, const char __user *ubuf,
 109                                      size_t len, loff_t *offp)
 110 {
 111         struct request_queue *q = file_inode(file)->i_private;
 112         char op[16] = { }, *s;
 113
 114         len = min(len, sizeof(op) - 1);
 115         if (copy_from_user(op, ubuf, len))
 116                 return -EFAULT;
 117         s = op;
 118         strsep(&s, " \t\n"); /* strip trailing whitespace */
 119         if (strcmp(op, "run") == 0) {
 120                 blk_mq_run_hw_queues(q, true);
 121         } else if (strcmp(op, "start") == 0) {
 122                 blk_mq_start_stopped_hw_queues(q, true);
 123         } else {
 124                 pr_err("%s: unsupported operation %s. Use either 'run' or 'start'\n",
 125                        __func__, op);
 126                 return -EINVAL;
 127         }
 128         return len;
 129 }
 130
 131 static int blk_queue_flags_open(struct inode *inode, struct file *file)
 132 {
 133         return single_open(file, blk_queue_flags_show, inode->i_private);
 134 }
 135
 136 static const struct file_operations blk_queue_flags_fops = {
 137         .open           = blk_queue_flags_open,
 138         .read           = seq_read,
 139         .llseek         = seq_lseek,
 140         .release        = single_release,
 141         .write          = blk_queue_flags_store,
 142 };
 143
 144 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
 145 {
 146         if (stat->nr_samples) {
 147                 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
 148                            stat->nr_samples, stat->mean, stat->min, stat->max);
 149         } else {
 150                 seq_puts(m, "samples=0");
 151         }
 152 }
 153
 154 static int queue_poll_stat_show(struct seq_file *m, void *v)
 155 {
 156         struct request_queue *q = m->private;
 157         int bucket;
 158
 159         for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
 160                 seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
 161                 print_stat(m, &q->poll_stat[2*bucket]);
 162                 seq_puts(m, "\n");
 163
 164                 seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
 165                 print_stat(m, &q->poll_stat[2*bucket+1]);
 166                 seq_puts(m, "\n");
 167         }
 168         return 0;
 169 }
 170
 171 static int queue_poll_stat_open(struct inode *inode, struct file *file)
 172 {
 173         return single_open(file, queue_poll_stat_show, inode->i_private);
 174 }
 175
 176 static const struct file_operations queue_poll_stat_fops = {
 177         .open           = queue_poll_stat_open,
 178         .read           = seq_read,
 179         .llseek         = seq_lseek,
 180         .release        = single_release,
 181 };
 182
 183 static const char *const hctx_state_name[] = {
 184         [BLK_MQ_S_STOPPED]       = "STOPPED",
 185         [BLK_MQ_S_TAG_ACTIVE]    = "TAG_ACTIVE",
 186         [BLK_MQ_S_SCHED_RESTART] = "SCHED_RESTART",
 187         [BLK_MQ_S_TAG_WAITING]   = "TAG_WAITING",
 188
 189 };
 190 static int hctx_state_show(struct seq_file *m, void *v)
 191 {
 192         struct blk_mq_hw_ctx *hctx = m->private;
 193
 194         blk_flags_show(m, hctx->state, hctx_state_name,
 195                        ARRAY_SIZE(hctx_state_name));
 196         seq_puts(m, "\n");
 197         return 0;
 198 }
 199
 200 static int hctx_state_open(struct inode *inode, struct file *file)
 201 {
 202         return single_open(file, hctx_state_show, inode->i_private);
 203 }
 204
 205 static const struct file_operations hctx_state_fops = {
 206         .open           = hctx_state_open,
 207         .read           = seq_read,
 208         .llseek         = seq_lseek,
 209         .release        = single_release,
 210 };
 211
 212 static const char *const alloc_policy_name[] = {
 213         [BLK_TAG_ALLOC_FIFO]    = "fifo",
 214         [BLK_TAG_ALLOC_RR]      = "rr",
 215 };
 216
 217 static const char *const hctx_flag_name[] = {
 218         [ilog2(BLK_MQ_F_SHOULD_MERGE)]  = "SHOULD_MERGE",
 219         [ilog2(BLK_MQ_F_TAG_SHARED)]    = "TAG_SHARED",
 220         [ilog2(BLK_MQ_F_SG_MERGE)]      = "SG_MERGE",
 221         [ilog2(BLK_MQ_F_BLOCKING)]      = "BLOCKING",
 222         [ilog2(BLK_MQ_F_NO_SCHED)]      = "NO_SCHED",
 223 };
 224
 225 static int hctx_flags_show(struct seq_file *m, void *v)
 226 {
 227         struct blk_mq_hw_ctx *hctx = m->private;
 228         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 229
 230         seq_puts(m, "alloc_policy=");
 231         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 232             alloc_policy_name[alloc_policy])
 233                 seq_puts(m, alloc_policy_name[alloc_policy]);
 234         else
 235                 seq_printf(m, "%d", alloc_policy);
 236         seq_puts(m, " ");
 237         blk_flags_show(m,
 238                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 239                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 240         seq_puts(m, "\n");
 241         return 0;
 242 }
 243
 244 static int hctx_flags_open(struct inode *inode, struct file *file)
 245 {
 246         return single_open(file, hctx_flags_show, inode->i_private);
 247 }
 248
 249 static const struct file_operations hctx_flags_fops = {
 250         .open           = hctx_flags_open,
 251         .read           = seq_read,
 252         .llseek         = seq_lseek,
 253         .release        = single_release,
 254 };
 255
 256 static const char *const op_name[] = {
 257         [REQ_OP_READ]           = "READ",
 258         [REQ_OP_WRITE]          = "WRITE",
 259         [REQ_OP_FLUSH]          = "FLUSH",
 260         [REQ_OP_DISCARD]        = "DISCARD",
 261         [REQ_OP_ZONE_REPORT]    = "ZONE_REPORT",
 262         [REQ_OP_SECURE_ERASE]   = "SECURE_ERASE",
 263         [REQ_OP_ZONE_RESET]     = "ZONE_RESET",
 264         [REQ_OP_WRITE_SAME]     = "WRITE_SAME",
 265         [REQ_OP_WRITE_ZEROES]   = "WRITE_ZEROES",
 266         [REQ_OP_SCSI_IN]        = "SCSI_IN",
 267         [REQ_OP_SCSI_OUT]       = "SCSI_OUT",
 268         [REQ_OP_DRV_IN]         = "DRV_IN",
 269         [REQ_OP_DRV_OUT]        = "DRV_OUT",
 270 };
 271
 272 static const char *const cmd_flag_name[] = {
 273         [__REQ_FAILFAST_DEV]            = "FAILFAST_DEV",
 274         [__REQ_FAILFAST_TRANSPORT]      = "FAILFAST_TRANSPORT",
 275         [__REQ_FAILFAST_DRIVER]         = "FAILFAST_DRIVER",
 276         [__REQ_SYNC]                    = "SYNC",
 277         [__REQ_META]                    = "META",
 278         [__REQ_PRIO]                    = "PRIO",
 279         [__REQ_NOMERGE]                 = "NOMERGE",
 280         [__REQ_IDLE]                    = "IDLE",
 281         [__REQ_INTEGRITY]               = "INTEGRITY",
 282         [__REQ_FUA]                     = "FUA",
 283         [__REQ_PREFLUSH]                = "PREFLUSH",
 284         [__REQ_RAHEAD]                  = "RAHEAD",
 285         [__REQ_BACKGROUND]              = "BACKGROUND",
 286         [__REQ_NR_BITS]                 = "NR_BITS",
 287 };
 288
 289 static const char *const rqf_name[] = {
 290         [ilog2((__force u32)RQF_SORTED)]                = "SORTED",
 291         [ilog2((__force u32)RQF_STARTED)]               = "STARTED",
 292         [ilog2((__force u32)RQF_QUEUED)]                = "QUEUED",
 293         [ilog2((__force u32)RQF_SOFTBARRIER)]           = "SOFTBARRIER",
 294         [ilog2((__force u32)RQF_FLUSH_SEQ)]             = "FLUSH_SEQ",
 295         [ilog2((__force u32)RQF_MIXED_MERGE)]           = "MIXED_MERGE",
 296         [ilog2((__force u32)RQF_MQ_INFLIGHT)]           = "MQ_INFLIGHT",
 297         [ilog2((__force u32)RQF_DONTPREP)]              = "DONTPREP",
 298         [ilog2((__force u32)RQF_PREEMPT)]               = "PREEMPT",
 299         [ilog2((__force u32)RQF_COPY_USER)]             = "COPY_USER",
 300         [ilog2((__force u32)RQF_FAILED)]                = "FAILED",
 301         [ilog2((__force u32)RQF_QUIET)]                 = "QUIET",
 302         [ilog2((__force u32)RQF_ELVPRIV)]               = "ELVPRIV",
 303         [ilog2((__force u32)RQF_IO_STAT)]               = "IO_STAT",
 304         [ilog2((__force u32)RQF_ALLOCED)]               = "ALLOCED",
 305         [ilog2((__force u32)RQF_PM)]                    = "PM",
 306         [ilog2((__force u32)RQF_HASHED)]                = "HASHED",
 307         [ilog2((__force u32)RQF_STATS)]                 = "STATS",
 308         [ilog2((__force u32)RQF_SPECIAL_PAYLOAD)]       = "SPECIAL_PAYLOAD",
 309 };
 310
 311 static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 312 {
 313         struct request *rq = list_entry_rq(v);
 314         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 315         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 316
 317         seq_printf(m, "%p {.op=", rq);
 318         if (op < ARRAY_SIZE(op_name) && op_name[op])
 319                 seq_printf(m, "%s", op_name[op]);
 320         else
 321                 seq_printf(m, "%d", op);
 322         seq_puts(m, ", .cmd_flags=");
 323         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 324                        ARRAY_SIZE(cmd_flag_name));
 325         seq_puts(m, ", .rq_flags=");
 326         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 327                        ARRAY_SIZE(rqf_name));
 328         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 329                    rq->internal_tag);
 330         if (mq_ops->show_rq)
 331                 mq_ops->show_rq(m, rq);
 332         seq_puts(m, "}\n");
 333         return 0;
 334 }
 335
 336 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 337         __acquires(&hctx->lock)
 338 {
 339         struct blk_mq_hw_ctx *hctx = m->private;
 340
 341         spin_lock(&hctx->lock);
 342         return seq_list_start(&hctx->dispatch, *pos);
 343 }
 344
 345 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 346 {
 347         struct blk_mq_hw_ctx *hctx = m->private;
 348
 349         return seq_list_next(v, &hctx->dispatch, pos);
 350 }
 351
 352 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 353         __releases(&hctx->lock)
 354 {
 355         struct blk_mq_hw_ctx *hctx = m->private;
 356
 357         spin_unlock(&hctx->lock);
 358 }
 359
 360 static const struct seq_operations hctx_dispatch_seq_ops = {
 361         .start  = hctx_dispatch_start,
 362         .next   = hctx_dispatch_next,
 363         .stop   = hctx_dispatch_stop,
 364         .show   = blk_mq_debugfs_rq_show,
 365 };
 366
 367 static int hctx_dispatch_open(struct inode *inode, struct file *file)
 368 {
 369         return blk_mq_debugfs_seq_open(inode, file, &hctx_dispatch_seq_ops);
 370 }
 371
 372 static const struct file_operations hctx_dispatch_fops = {
 373         .open           = hctx_dispatch_open,
 374         .read           = seq_read,
 375         .llseek         = seq_lseek,
 376         .release        = seq_release,
 377 };
 378
 379 static int hctx_ctx_map_show(struct seq_file *m, void *v)
 380 {
 381         struct blk_mq_hw_ctx *hctx = m->private;
 382
 383         sbitmap_bitmap_show(&hctx->ctx_map, m);
 384         return 0;
 385 }
 386
 387 static int hctx_ctx_map_open(struct inode *inode, struct file *file)
 388 {
 389         return single_open(file, hctx_ctx_map_show, inode->i_private);
 390 }
 391
 392 static const struct file_operations hctx_ctx_map_fops = {
 393         .open           = hctx_ctx_map_open,
 394         .read           = seq_read,
 395         .llseek         = seq_lseek,
 396         .release        = single_release,
 397 };
 398
 399 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 400                                      struct blk_mq_tags *tags)
 401 {
 402         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 403         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 404         seq_printf(m, "active_queues=%d\n",
 405                    atomic_read(&tags->active_queues));
 406
 407         seq_puts(m, "\nbitmap_tags:\n");
 408         sbitmap_queue_show(&tags->bitmap_tags, m);
 409
 410         if (tags->nr_reserved_tags) {
 411                 seq_puts(m, "\nbreserved_tags:\n");
 412                 sbitmap_queue_show(&tags->breserved_tags, m);
 413         }
 414 }
 415
 416 static int hctx_tags_show(struct seq_file *m, void *v)
 417 {
 418         struct blk_mq_hw_ctx *hctx = m->private;
 419         struct request_queue *q = hctx->queue;
 420         int res;
 421
 422         res = mutex_lock_interruptible(&q->sysfs_lock);
 423         if (res)
 424                 goto out;
 425         if (hctx->tags)
 426                 blk_mq_debugfs_tags_show(m, hctx->tags);
 427         mutex_unlock(&q->sysfs_lock);
 428
 429 out:
 430         return res;
 431 }
 432
 433 static int hctx_tags_open(struct inode *inode, struct file *file)
 434 {
 435         return single_open(file, hctx_tags_show, inode->i_private);
 436 }
 437
 438 static const struct file_operations hctx_tags_fops = {
 439         .open           = hctx_tags_open,
 440         .read           = seq_read,
 441         .llseek         = seq_lseek,
 442         .release        = single_release,
 443 };
 444
 445 static int hctx_tags_bitmap_show(struct seq_file *m, void *v)
 446 {
 447         struct blk_mq_hw_ctx *hctx = m->private;
 448         struct request_queue *q = hctx->queue;
 449         int res;
 450
 451         res = mutex_lock_interruptible(&q->sysfs_lock);
 452         if (res)
 453                 goto out;
 454         if (hctx->tags)
 455                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 456         mutex_unlock(&q->sysfs_lock);
 457
 458 out:
 459         return res;
 460 }
 461
 462 static int hctx_tags_bitmap_open(struct inode *inode, struct file *file)
 463 {
 464         return single_open(file, hctx_tags_bitmap_show, inode->i_private);
 465 }
 466
 467 static const struct file_operations hctx_tags_bitmap_fops = {
 468         .open           = hctx_tags_bitmap_open,
 469         .read           = seq_read,
 470         .llseek         = seq_lseek,
 471         .release        = single_release,
 472 };
 473
 474 static int hctx_sched_tags_show(struct seq_file *m, void *v)
 475 {
 476         struct blk_mq_hw_ctx *hctx = m->private;
 477         struct request_queue *q = hctx->queue;
 478         int res;
 479
 480         res = mutex_lock_interruptible(&q->sysfs_lock);
 481         if (res)
 482                 goto out;
 483         if (hctx->sched_tags)
 484                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 485         mutex_unlock(&q->sysfs_lock);
 486
 487 out:
 488         return res;
 489 }
 490
 491 static int hctx_sched_tags_open(struct inode *inode, struct file *file)
 492 {
 493         return single_open(file, hctx_sched_tags_show, inode->i_private);
 494 }
 495
 496 static const struct file_operations hctx_sched_tags_fops = {
 497         .open           = hctx_sched_tags_open,
 498         .read           = seq_read,
 499         .llseek         = seq_lseek,
 500         .release        = single_release,
 501 };
 502
 503 static int hctx_sched_tags_bitmap_show(struct seq_file *m, void *v)
 504 {
 505         struct blk_mq_hw_ctx *hctx = m->private;
 506         struct request_queue *q = hctx->queue;
 507         int res;
 508
 509         res = mutex_lock_interruptible(&q->sysfs_lock);
 510         if (res)
 511                 goto out;
 512         if (hctx->sched_tags)
 513                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 514         mutex_unlock(&q->sysfs_lock);
 515
 516 out:
 517         return res;
 518 }
 519
 520 static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file)
 521 {
 522         return single_open(file, hctx_sched_tags_bitmap_show, inode->i_private);
 523 }
 524
 525 static const struct file_operations hctx_sched_tags_bitmap_fops = {
 526         .open           = hctx_sched_tags_bitmap_open,
 527         .read           = seq_read,
 528         .llseek         = seq_lseek,
 529         .release        = single_release,
 530 };
 531
 532 static int hctx_io_poll_show(struct seq_file *m, void *v)
 533 {
 534         struct blk_mq_hw_ctx *hctx = m->private;
 535
 536         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 537         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 538         seq_printf(m, "success=%lu\n", hctx->poll_success);
 539         return 0;
 540 }
 541
 542 static int hctx_io_poll_open(struct inode *inode, struct file *file)
 543 {
 544         return single_open(file, hctx_io_poll_show, inode->i_private);
 545 }
 546
 547 static ssize_t hctx_io_poll_write(struct file *file, const char __user *buf,
 548                                   size_t count, loff_t *ppos)
 549 {
 550         struct seq_file *m = file->private_data;
 551         struct blk_mq_hw_ctx *hctx = m->private;
 552
 553         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 554         return count;
 555 }
 556
 557 static const struct file_operations hctx_io_poll_fops = {
 558         .open           = hctx_io_poll_open,
 559         .read           = seq_read,
 560         .write          = hctx_io_poll_write,
 561         .llseek         = seq_lseek,
 562         .release        = single_release,
 563 };
 564
 565 static int hctx_dispatched_show(struct seq_file *m, void *v)
 566 {
 567         struct blk_mq_hw_ctx *hctx = m->private;
 568         int i;
 569
 570         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 571
 572         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 573                 unsigned int d = 1U << (i - 1);
 574
 575                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 576         }
 577
 578         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 579         return 0;
 580 }
 581
 582 static int hctx_dispatched_open(struct inode *inode, struct file *file)
 583 {
 584         return single_open(file, hctx_dispatched_show, inode->i_private);
 585 }
 586
 587 static ssize_t hctx_dispatched_write(struct file *file, const char __user *buf,
 588                                      size_t count, loff_t *ppos)
 589 {
 590         struct seq_file *m = file->private_data;
 591         struct blk_mq_hw_ctx *hctx = m->private;
 592         int i;
 593
 594         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 595                 hctx->dispatched[i] = 0;
 596         return count;
 597 }
 598
 599 static const struct file_operations hctx_dispatched_fops = {
 600         .open           = hctx_dispatched_open,
 601         .read           = seq_read,
 602         .write          = hctx_dispatched_write,
 603         .llseek         = seq_lseek,
 604         .release        = single_release,
 605 };
 606
 607 static int hctx_queued_show(struct seq_file *m, void *v)
 608 {
 609         struct blk_mq_hw_ctx *hctx = m->private;
 610
 611         seq_printf(m, "%lu\n", hctx->queued);
 612         return 0;
 613 }
 614
 615 static int hctx_queued_open(struct inode *inode, struct file *file)
 616 {
 617         return single_open(file, hctx_queued_show, inode->i_private);
 618 }
 619
 620 static ssize_t hctx_queued_write(struct file *file, const char __user *buf,
 621                                  size_t count, loff_t *ppos)
 622 {
 623         struct seq_file *m = file->private_data;
 624         struct blk_mq_hw_ctx *hctx = m->private;
 625
 626         hctx->queued = 0;
 627         return count;
 628 }
 629
 630 static const struct file_operations hctx_queued_fops = {
 631         .open           = hctx_queued_open,
 632         .read           = seq_read,
 633         .write          = hctx_queued_write,
 634         .llseek         = seq_lseek,
 635         .release        = single_release,
 636 };
 637
 638 static int hctx_run_show(struct seq_file *m, void *v)
 639 {
 640         struct blk_mq_hw_ctx *hctx = m->private;
 641
 642         seq_printf(m, "%lu\n", hctx->run);
 643         return 0;
 644 }
 645
 646 static int hctx_run_open(struct inode *inode, struct file *file)
 647 {
 648         return single_open(file, hctx_run_show, inode->i_private);
 649 }
 650
 651 static ssize_t hctx_run_write(struct file *file, const char __user *buf,
 652                                  size_t count, loff_t *ppos)
 653 {
 654         struct seq_file *m = file->private_data;
 655         struct blk_mq_hw_ctx *hctx = m->private;
 656
 657         hctx->run = 0;
 658         return count;
 659 }
 660
 661 static const struct file_operations hctx_run_fops = {
 662         .open           = hctx_run_open,
 663         .read           = seq_read,
 664         .write          = hctx_run_write,
 665         .llseek         = seq_lseek,
 666         .release        = single_release,
 667 };
 668
 669 static int hctx_active_show(struct seq_file *m, void *v)
 670 {
 671         struct blk_mq_hw_ctx *hctx = m->private;
 672
 673         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 674         return 0;
 675 }
 676
 677 static int hctx_active_open(struct inode *inode, struct file *file)
 678 {
 679         return single_open(file, hctx_active_show, inode->i_private);
 680 }
 681
 682 static const struct file_operations hctx_active_fops = {
 683         .open           = hctx_active_open,
 684         .read           = seq_read,
 685         .llseek         = seq_lseek,
 686         .release        = single_release,
 687 };
 688
 689 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 690         __acquires(&ctx->lock)
 691 {
 692         struct blk_mq_ctx *ctx = m->private;
 693
 694         spin_lock(&ctx->lock);
 695         return seq_list_start(&ctx->rq_list, *pos);
 696 }
 697
 698 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
 699 {
 700         struct blk_mq_ctx *ctx = m->private;
 701
 702         return seq_list_next(v, &ctx->rq_list, pos);
 703 }
 704
 705 static void ctx_rq_list_stop(struct seq_file *m, void *v)
 706         __releases(&ctx->lock)
 707 {
 708         struct blk_mq_ctx *ctx = m->private;
 709
 710         spin_unlock(&ctx->lock);
 711 }
 712
 713 static const struct seq_operations ctx_rq_list_seq_ops = {
 714         .start  = ctx_rq_list_start,
 715         .next   = ctx_rq_list_next,
 716         .stop   = ctx_rq_list_stop,
 717         .show   = blk_mq_debugfs_rq_show,
 718 };
 719
 720 static int ctx_rq_list_open(struct inode *inode, struct file *file)
 721 {
 722         return blk_mq_debugfs_seq_open(inode, file, &ctx_rq_list_seq_ops);
 723 }
 724
 725 static const struct file_operations ctx_rq_list_fops = {
 726         .open           = ctx_rq_list_open,
 727         .read           = seq_read,
 728         .llseek         = seq_lseek,
 729         .release        = seq_release,
 730 };
 731
 732 static int ctx_dispatched_show(struct seq_file *m, void *v)
 733 {
 734         struct blk_mq_ctx *ctx = m->private;
 735
 736         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 737         return 0;
 738 }
 739
 740 static int ctx_dispatched_open(struct inode *inode, struct file *file)
 741 {
 742         return single_open(file, ctx_dispatched_show, inode->i_private);
 743 }
 744
 745 static ssize_t ctx_dispatched_write(struct file *file, const char __user *buf,
 746                                     size_t count, loff_t *ppos)
 747 {
 748         struct seq_file *m = file->private_data;
 749         struct blk_mq_ctx *ctx = m->private;
 750
 751         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 752         return count;
 753 }
 754
 755 static const struct file_operations ctx_dispatched_fops = {
 756         .open           = ctx_dispatched_open,
 757         .read           = seq_read,
 758         .write          = ctx_dispatched_write,
 759         .llseek         = seq_lseek,
 760         .release        = single_release,
 761 };
 762
 763 static int ctx_merged_show(struct seq_file *m, void *v)
 764 {
 765         struct blk_mq_ctx *ctx = m->private;
 766
 767         seq_printf(m, "%lu\n", ctx->rq_merged);
 768         return 0;
 769 }
 770
 771 static int ctx_merged_open(struct inode *inode, struct file *file)
 772 {
 773         return single_open(file, ctx_merged_show, inode->i_private);
 774 }
 775
 776 static ssize_t ctx_merged_write(struct file *file, const char __user *buf,
 777                                     size_t count, loff_t *ppos)
 778 {
 779         struct seq_file *m = file->private_data;
 780         struct blk_mq_ctx *ctx = m->private;
 781
 782         ctx->rq_merged = 0;
 783         return count;
 784 }
 785
 786 static const struct file_operations ctx_merged_fops = {
 787         .open           = ctx_merged_open,
 788         .read           = seq_read,
 789         .write          = ctx_merged_write,
 790         .llseek         = seq_lseek,
 791         .release        = single_release,
 792 };
 793
 794 static int ctx_completed_show(struct seq_file *m, void *v)
 795 {
 796         struct blk_mq_ctx *ctx = m->private;
 797
 798         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 799         return 0;
 800 }
 801
 802 static int ctx_completed_open(struct inode *inode, struct file *file)
 803 {
 804         return single_open(file, ctx_completed_show, inode->i_private);
 805 }
 806
 807 static ssize_t ctx_completed_write(struct file *file, const char __user *buf,
 808                                    size_t count, loff_t *ppos)
 809 {
 810         struct seq_file *m = file->private_data;
 811         struct blk_mq_ctx *ctx = m->private;
 812
 813         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 814         return count;
 815 }
 816
 817 static const struct file_operations ctx_completed_fops = {
 818         .open           = ctx_completed_open,
 819         .read           = seq_read,
 820         .write          = ctx_completed_write,
 821         .llseek         = seq_lseek,
 822         .release        = single_release,
 823 };
 824
 825 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 826         {"poll_stat", 0400, &queue_poll_stat_fops},
 827         {"state", 0600, &blk_queue_flags_fops},
 828         {},
 829 };
 830
 831 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 832         {"state", 0400, &hctx_state_fops},
 833         {"flags", 0400, &hctx_flags_fops},
 834         {"dispatch", 0400, &hctx_dispatch_fops},
 835         {"ctx_map", 0400, &hctx_ctx_map_fops},
 836         {"tags", 0400, &hctx_tags_fops},
 837         {"tags_bitmap", 0400, &hctx_tags_bitmap_fops},
 838         {"sched_tags", 0400, &hctx_sched_tags_fops},
 839         {"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops},
 840         {"io_poll", 0600, &hctx_io_poll_fops},
 841         {"dispatched", 0600, &hctx_dispatched_fops},
 842         {"queued", 0600, &hctx_queued_fops},
 843         {"run", 0600, &hctx_run_fops},
 844         {"active", 0400, &hctx_active_fops},
 845         {},
 846 };
 847
 848 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 849         {"rq_list", 0400, &ctx_rq_list_fops},
 850         {"dispatched", 0600, &ctx_dispatched_fops},
 851         {"merged", 0600, &ctx_merged_fops},
 852         {"completed", 0600, &ctx_completed_fops},
 853         {},
 854 };
 855
 856 int blk_mq_debugfs_register(struct request_queue *q)
 857 {
 858         if (!blk_debugfs_root)
 859                 return -ENOENT;
 860
 861         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 862                                             blk_debugfs_root);
 863         if (!q->debugfs_dir)
 864                 goto err;
 865
 866         if (blk_mq_debugfs_register_mq(q))
 867                 goto err;
 868
 869         return 0;
 870
 871 err:
 872         blk_mq_debugfs_unregister(q);
 873         return -ENOMEM;
 874 }
 875
 876 void blk_mq_debugfs_unregister(struct request_queue *q)
 877 {
 878         debugfs_remove_recursive(q->debugfs_dir);
 879         q->mq_debugfs_dir = NULL;
 880         q->debugfs_dir = NULL;
 881 }
 882
 883 static bool debugfs_create_files(struct dentry *parent, void *data,
 884                                 const struct blk_mq_debugfs_attr *attr)
 885 {
 886         for (; attr->name; attr++) {
 887                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 888                                          data, attr->fops))
 889                         return false;
 890         }
 891         return true;
 892 }
 893
 894 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
 895                                        struct blk_mq_ctx *ctx,
 896                                        struct dentry *hctx_dir)
 897 {
 898         struct dentry *ctx_dir;
 899         char name[20];
 900
 901         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 902         ctx_dir = debugfs_create_dir(name, hctx_dir);
 903         if (!ctx_dir)
 904                 return -ENOMEM;
 905
 906         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 907                 return -ENOMEM;
 908
 909         return 0;
 910 }
 911
 912 static int blk_mq_debugfs_register_hctx(struct request_queue *q,
 913                                         struct blk_mq_hw_ctx *hctx)
 914 {
 915         struct blk_mq_ctx *ctx;
 916         struct dentry *hctx_dir;
 917         char name[20];
 918         int i;
 919
 920         snprintf(name, sizeof(name), "%u", hctx->queue_num);
 921         hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
 922         if (!hctx_dir)
 923                 return -ENOMEM;
 924
 925         if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
 926                 return -ENOMEM;
 927
 928         hctx_for_each_ctx(hctx, ctx, i) {
 929                 if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
 930                         return -ENOMEM;
 931         }
 932
 933         return 0;
 934 }
 935
 936 int blk_mq_debugfs_register_mq(struct request_queue *q)
 937 {
 938         struct blk_mq_hw_ctx *hctx;
 939         int i;
 940
 941         if (!q->debugfs_dir)
 942                 return -ENOENT;
 943
 944         q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
 945         if (!q->mq_debugfs_dir)
 946                 goto err;
 947
 948         if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs))
 949                 goto err;
 950
 951         queue_for_each_hw_ctx(q, hctx, i) {
 952                 if (blk_mq_debugfs_register_hctx(q, hctx))
 953                         goto err;
 954         }
 955
 956         return 0;
 957
 958 err:
 959         blk_mq_debugfs_unregister_mq(q);
 960         return -ENOMEM;
 961 }
 962
 963 void blk_mq_debugfs_unregister_mq(struct request_queue *q)
 964 {
 965         debugfs_remove_recursive(q->mq_debugfs_dir);
 966         q->mq_debugfs_dir = NULL;
 967 }