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 unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 315
 316         seq_printf(m, "%p {.op=", rq);
 317         if (op < ARRAY_SIZE(op_name) && op_name[op])
 318                 seq_printf(m, "%s", op_name[op]);
 319         else
 320                 seq_printf(m, "%d", op);
 321         seq_puts(m, ", .cmd_flags=");
 322         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 323                        ARRAY_SIZE(cmd_flag_name));
 324         seq_puts(m, ", .rq_flags=");
 325         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 326                        ARRAY_SIZE(rqf_name));
 327         seq_printf(m, ", .tag=%d, .internal_tag=%d}\n", rq->tag,
 328                    rq->internal_tag);
 329         return 0;
 330 }
 331
 332 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 333         __acquires(&hctx->lock)
 334 {
 335         struct blk_mq_hw_ctx *hctx = m->private;
 336
 337         spin_lock(&hctx->lock);
 338         return seq_list_start(&hctx->dispatch, *pos);
 339 }
 340
 341 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 342 {
 343         struct blk_mq_hw_ctx *hctx = m->private;
 344
 345         return seq_list_next(v, &hctx->dispatch, pos);
 346 }
 347
 348 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 349         __releases(&hctx->lock)
 350 {
 351         struct blk_mq_hw_ctx *hctx = m->private;
 352
 353         spin_unlock(&hctx->lock);
 354 }
 355
 356 static const struct seq_operations hctx_dispatch_seq_ops = {
 357         .start  = hctx_dispatch_start,
 358         .next   = hctx_dispatch_next,
 359         .stop   = hctx_dispatch_stop,
 360         .show   = blk_mq_debugfs_rq_show,
 361 };
 362
 363 static int hctx_dispatch_open(struct inode *inode, struct file *file)
 364 {
 365         return blk_mq_debugfs_seq_open(inode, file, &hctx_dispatch_seq_ops);
 366 }
 367
 368 static const struct file_operations hctx_dispatch_fops = {
 369         .open           = hctx_dispatch_open,
 370         .read           = seq_read,
 371         .llseek         = seq_lseek,
 372         .release        = seq_release,
 373 };
 374
 375 static int hctx_ctx_map_show(struct seq_file *m, void *v)
 376 {
 377         struct blk_mq_hw_ctx *hctx = m->private;
 378
 379         sbitmap_bitmap_show(&hctx->ctx_map, m);
 380         return 0;
 381 }
 382
 383 static int hctx_ctx_map_open(struct inode *inode, struct file *file)
 384 {
 385         return single_open(file, hctx_ctx_map_show, inode->i_private);
 386 }
 387
 388 static const struct file_operations hctx_ctx_map_fops = {
 389         .open           = hctx_ctx_map_open,
 390         .read           = seq_read,
 391         .llseek         = seq_lseek,
 392         .release        = single_release,
 393 };
 394
 395 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 396                                      struct blk_mq_tags *tags)
 397 {
 398         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 399         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 400         seq_printf(m, "active_queues=%d\n",
 401                    atomic_read(&tags->active_queues));
 402
 403         seq_puts(m, "\nbitmap_tags:\n");
 404         sbitmap_queue_show(&tags->bitmap_tags, m);
 405
 406         if (tags->nr_reserved_tags) {
 407                 seq_puts(m, "\nbreserved_tags:\n");
 408                 sbitmap_queue_show(&tags->breserved_tags, m);
 409         }
 410 }
 411
 412 static int hctx_tags_show(struct seq_file *m, void *v)
 413 {
 414         struct blk_mq_hw_ctx *hctx = m->private;
 415         struct request_queue *q = hctx->queue;
 416         int res;
 417
 418         res = mutex_lock_interruptible(&q->sysfs_lock);
 419         if (res)
 420                 goto out;
 421         if (hctx->tags)
 422                 blk_mq_debugfs_tags_show(m, hctx->tags);
 423         mutex_unlock(&q->sysfs_lock);
 424
 425 out:
 426         return res;
 427 }
 428
 429 static int hctx_tags_open(struct inode *inode, struct file *file)
 430 {
 431         return single_open(file, hctx_tags_show, inode->i_private);
 432 }
 433
 434 static const struct file_operations hctx_tags_fops = {
 435         .open           = hctx_tags_open,
 436         .read           = seq_read,
 437         .llseek         = seq_lseek,
 438         .release        = single_release,
 439 };
 440
 441 static int hctx_tags_bitmap_show(struct seq_file *m, void *v)
 442 {
 443         struct blk_mq_hw_ctx *hctx = m->private;
 444         struct request_queue *q = hctx->queue;
 445         int res;
 446
 447         res = mutex_lock_interruptible(&q->sysfs_lock);
 448         if (res)
 449                 goto out;
 450         if (hctx->tags)
 451                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 452         mutex_unlock(&q->sysfs_lock);
 453
 454 out:
 455         return res;
 456 }
 457
 458 static int hctx_tags_bitmap_open(struct inode *inode, struct file *file)
 459 {
 460         return single_open(file, hctx_tags_bitmap_show, inode->i_private);
 461 }
 462
 463 static const struct file_operations hctx_tags_bitmap_fops = {
 464         .open           = hctx_tags_bitmap_open,
 465         .read           = seq_read,
 466         .llseek         = seq_lseek,
 467         .release        = single_release,
 468 };
 469
 470 static int hctx_sched_tags_show(struct seq_file *m, void *v)
 471 {
 472         struct blk_mq_hw_ctx *hctx = m->private;
 473         struct request_queue *q = hctx->queue;
 474         int res;
 475
 476         res = mutex_lock_interruptible(&q->sysfs_lock);
 477         if (res)
 478                 goto out;
 479         if (hctx->sched_tags)
 480                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 481         mutex_unlock(&q->sysfs_lock);
 482
 483 out:
 484         return res;
 485 }
 486
 487 static int hctx_sched_tags_open(struct inode *inode, struct file *file)
 488 {
 489         return single_open(file, hctx_sched_tags_show, inode->i_private);
 490 }
 491
 492 static const struct file_operations hctx_sched_tags_fops = {
 493         .open           = hctx_sched_tags_open,
 494         .read           = seq_read,
 495         .llseek         = seq_lseek,
 496         .release        = single_release,
 497 };
 498
 499 static int hctx_sched_tags_bitmap_show(struct seq_file *m, void *v)
 500 {
 501         struct blk_mq_hw_ctx *hctx = m->private;
 502         struct request_queue *q = hctx->queue;
 503         int res;
 504
 505         res = mutex_lock_interruptible(&q->sysfs_lock);
 506         if (res)
 507                 goto out;
 508         if (hctx->sched_tags)
 509                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 510         mutex_unlock(&q->sysfs_lock);
 511
 512 out:
 513         return res;
 514 }
 515
 516 static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file)
 517 {
 518         return single_open(file, hctx_sched_tags_bitmap_show, inode->i_private);
 519 }
 520
 521 static const struct file_operations hctx_sched_tags_bitmap_fops = {
 522         .open           = hctx_sched_tags_bitmap_open,
 523         .read           = seq_read,
 524         .llseek         = seq_lseek,
 525         .release        = single_release,
 526 };
 527
 528 static int hctx_io_poll_show(struct seq_file *m, void *v)
 529 {
 530         struct blk_mq_hw_ctx *hctx = m->private;
 531
 532         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 533         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 534         seq_printf(m, "success=%lu\n", hctx->poll_success);
 535         return 0;
 536 }
 537
 538 static int hctx_io_poll_open(struct inode *inode, struct file *file)
 539 {
 540         return single_open(file, hctx_io_poll_show, inode->i_private);
 541 }
 542
 543 static ssize_t hctx_io_poll_write(struct file *file, const char __user *buf,
 544                                   size_t count, loff_t *ppos)
 545 {
 546         struct seq_file *m = file->private_data;
 547         struct blk_mq_hw_ctx *hctx = m->private;
 548
 549         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 550         return count;
 551 }
 552
 553 static const struct file_operations hctx_io_poll_fops = {
 554         .open           = hctx_io_poll_open,
 555         .read           = seq_read,
 556         .write          = hctx_io_poll_write,
 557         .llseek         = seq_lseek,
 558         .release        = single_release,
 559 };
 560
 561 static int hctx_dispatched_show(struct seq_file *m, void *v)
 562 {
 563         struct blk_mq_hw_ctx *hctx = m->private;
 564         int i;
 565
 566         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 567
 568         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 569                 unsigned int d = 1U << (i - 1);
 570
 571                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 572         }
 573
 574         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 575         return 0;
 576 }
 577
 578 static int hctx_dispatched_open(struct inode *inode, struct file *file)
 579 {
 580         return single_open(file, hctx_dispatched_show, inode->i_private);
 581 }
 582
 583 static ssize_t hctx_dispatched_write(struct file *file, const char __user *buf,
 584                                      size_t count, loff_t *ppos)
 585 {
 586         struct seq_file *m = file->private_data;
 587         struct blk_mq_hw_ctx *hctx = m->private;
 588         int i;
 589
 590         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 591                 hctx->dispatched[i] = 0;
 592         return count;
 593 }
 594
 595 static const struct file_operations hctx_dispatched_fops = {
 596         .open           = hctx_dispatched_open,
 597         .read           = seq_read,
 598         .write          = hctx_dispatched_write,
 599         .llseek         = seq_lseek,
 600         .release        = single_release,
 601 };
 602
 603 static int hctx_queued_show(struct seq_file *m, void *v)
 604 {
 605         struct blk_mq_hw_ctx *hctx = m->private;
 606
 607         seq_printf(m, "%lu\n", hctx->queued);
 608         return 0;
 609 }
 610
 611 static int hctx_queued_open(struct inode *inode, struct file *file)
 612 {
 613         return single_open(file, hctx_queued_show, inode->i_private);
 614 }
 615
 616 static ssize_t hctx_queued_write(struct file *file, const char __user *buf,
 617                                  size_t count, loff_t *ppos)
 618 {
 619         struct seq_file *m = file->private_data;
 620         struct blk_mq_hw_ctx *hctx = m->private;
 621
 622         hctx->queued = 0;
 623         return count;
 624 }
 625
 626 static const struct file_operations hctx_queued_fops = {
 627         .open           = hctx_queued_open,
 628         .read           = seq_read,
 629         .write          = hctx_queued_write,
 630         .llseek         = seq_lseek,
 631         .release        = single_release,
 632 };
 633
 634 static int hctx_run_show(struct seq_file *m, void *v)
 635 {
 636         struct blk_mq_hw_ctx *hctx = m->private;
 637
 638         seq_printf(m, "%lu\n", hctx->run);
 639         return 0;
 640 }
 641
 642 static int hctx_run_open(struct inode *inode, struct file *file)
 643 {
 644         return single_open(file, hctx_run_show, inode->i_private);
 645 }
 646
 647 static ssize_t hctx_run_write(struct file *file, const char __user *buf,
 648                                  size_t count, loff_t *ppos)
 649 {
 650         struct seq_file *m = file->private_data;
 651         struct blk_mq_hw_ctx *hctx = m->private;
 652
 653         hctx->run = 0;
 654         return count;
 655 }
 656
 657 static const struct file_operations hctx_run_fops = {
 658         .open           = hctx_run_open,
 659         .read           = seq_read,
 660         .write          = hctx_run_write,
 661         .llseek         = seq_lseek,
 662         .release        = single_release,
 663 };
 664
 665 static int hctx_active_show(struct seq_file *m, void *v)
 666 {
 667         struct blk_mq_hw_ctx *hctx = m->private;
 668
 669         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 670         return 0;
 671 }
 672
 673 static int hctx_active_open(struct inode *inode, struct file *file)
 674 {
 675         return single_open(file, hctx_active_show, inode->i_private);
 676 }
 677
 678 static const struct file_operations hctx_active_fops = {
 679         .open           = hctx_active_open,
 680         .read           = seq_read,
 681         .llseek         = seq_lseek,
 682         .release        = single_release,
 683 };
 684
 685 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 686         __acquires(&ctx->lock)
 687 {
 688         struct blk_mq_ctx *ctx = m->private;
 689
 690         spin_lock(&ctx->lock);
 691         return seq_list_start(&ctx->rq_list, *pos);
 692 }
 693
 694 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
 695 {
 696         struct blk_mq_ctx *ctx = m->private;
 697
 698         return seq_list_next(v, &ctx->rq_list, pos);
 699 }
 700
 701 static void ctx_rq_list_stop(struct seq_file *m, void *v)
 702         __releases(&ctx->lock)
 703 {
 704         struct blk_mq_ctx *ctx = m->private;
 705
 706         spin_unlock(&ctx->lock);
 707 }
 708
 709 static const struct seq_operations ctx_rq_list_seq_ops = {
 710         .start  = ctx_rq_list_start,
 711         .next   = ctx_rq_list_next,
 712         .stop   = ctx_rq_list_stop,
 713         .show   = blk_mq_debugfs_rq_show,
 714 };
 715
 716 static int ctx_rq_list_open(struct inode *inode, struct file *file)
 717 {
 718         return blk_mq_debugfs_seq_open(inode, file, &ctx_rq_list_seq_ops);
 719 }
 720
 721 static const struct file_operations ctx_rq_list_fops = {
 722         .open           = ctx_rq_list_open,
 723         .read           = seq_read,
 724         .llseek         = seq_lseek,
 725         .release        = seq_release,
 726 };
 727
 728 static int ctx_dispatched_show(struct seq_file *m, void *v)
 729 {
 730         struct blk_mq_ctx *ctx = m->private;
 731
 732         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 733         return 0;
 734 }
 735
 736 static int ctx_dispatched_open(struct inode *inode, struct file *file)
 737 {
 738         return single_open(file, ctx_dispatched_show, inode->i_private);
 739 }
 740
 741 static ssize_t ctx_dispatched_write(struct file *file, const char __user *buf,
 742                                     size_t count, loff_t *ppos)
 743 {
 744         struct seq_file *m = file->private_data;
 745         struct blk_mq_ctx *ctx = m->private;
 746
 747         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 748         return count;
 749 }
 750
 751 static const struct file_operations ctx_dispatched_fops = {
 752         .open           = ctx_dispatched_open,
 753         .read           = seq_read,
 754         .write          = ctx_dispatched_write,
 755         .llseek         = seq_lseek,
 756         .release        = single_release,
 757 };
 758
 759 static int ctx_merged_show(struct seq_file *m, void *v)
 760 {
 761         struct blk_mq_ctx *ctx = m->private;
 762
 763         seq_printf(m, "%lu\n", ctx->rq_merged);
 764         return 0;
 765 }
 766
 767 static int ctx_merged_open(struct inode *inode, struct file *file)
 768 {
 769         return single_open(file, ctx_merged_show, inode->i_private);
 770 }
 771
 772 static ssize_t ctx_merged_write(struct file *file, const char __user *buf,
 773                                     size_t count, loff_t *ppos)
 774 {
 775         struct seq_file *m = file->private_data;
 776         struct blk_mq_ctx *ctx = m->private;
 777
 778         ctx->rq_merged = 0;
 779         return count;
 780 }
 781
 782 static const struct file_operations ctx_merged_fops = {
 783         .open           = ctx_merged_open,
 784         .read           = seq_read,
 785         .write          = ctx_merged_write,
 786         .llseek         = seq_lseek,
 787         .release        = single_release,
 788 };
 789
 790 static int ctx_completed_show(struct seq_file *m, void *v)
 791 {
 792         struct blk_mq_ctx *ctx = m->private;
 793
 794         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 795         return 0;
 796 }
 797
 798 static int ctx_completed_open(struct inode *inode, struct file *file)
 799 {
 800         return single_open(file, ctx_completed_show, inode->i_private);
 801 }
 802
 803 static ssize_t ctx_completed_write(struct file *file, const char __user *buf,
 804                                    size_t count, loff_t *ppos)
 805 {
 806         struct seq_file *m = file->private_data;
 807         struct blk_mq_ctx *ctx = m->private;
 808
 809         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 810         return count;
 811 }
 812
 813 static const struct file_operations ctx_completed_fops = {
 814         .open           = ctx_completed_open,
 815         .read           = seq_read,
 816         .write          = ctx_completed_write,
 817         .llseek         = seq_lseek,
 818         .release        = single_release,
 819 };
 820
 821 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 822         {"poll_stat", 0400, &queue_poll_stat_fops},
 823         {"state", 0600, &blk_queue_flags_fops},
 824         {},
 825 };
 826
 827 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 828         {"state", 0400, &hctx_state_fops},
 829         {"flags", 0400, &hctx_flags_fops},
 830         {"dispatch", 0400, &hctx_dispatch_fops},
 831         {"ctx_map", 0400, &hctx_ctx_map_fops},
 832         {"tags", 0400, &hctx_tags_fops},
 833         {"tags_bitmap", 0400, &hctx_tags_bitmap_fops},
 834         {"sched_tags", 0400, &hctx_sched_tags_fops},
 835         {"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops},
 836         {"io_poll", 0600, &hctx_io_poll_fops},
 837         {"dispatched", 0600, &hctx_dispatched_fops},
 838         {"queued", 0600, &hctx_queued_fops},
 839         {"run", 0600, &hctx_run_fops},
 840         {"active", 0400, &hctx_active_fops},
 841         {},
 842 };
 843
 844 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 845         {"rq_list", 0400, &ctx_rq_list_fops},
 846         {"dispatched", 0600, &ctx_dispatched_fops},
 847         {"merged", 0600, &ctx_merged_fops},
 848         {"completed", 0600, &ctx_completed_fops},
 849         {},
 850 };
 851
 852 int blk_mq_debugfs_register(struct request_queue *q)
 853 {
 854         if (!blk_debugfs_root)
 855                 return -ENOENT;
 856
 857         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 858                                             blk_debugfs_root);
 859         if (!q->debugfs_dir)
 860                 goto err;
 861
 862         if (blk_mq_debugfs_register_mq(q))
 863                 goto err;
 864
 865         return 0;
 866
 867 err:
 868         blk_mq_debugfs_unregister(q);
 869         return -ENOMEM;
 870 }
 871
 872 void blk_mq_debugfs_unregister(struct request_queue *q)
 873 {
 874         debugfs_remove_recursive(q->debugfs_dir);
 875         q->mq_debugfs_dir = NULL;
 876         q->debugfs_dir = NULL;
 877 }
 878
 879 static bool debugfs_create_files(struct dentry *parent, void *data,
 880                                 const struct blk_mq_debugfs_attr *attr)
 881 {
 882         for (; attr->name; attr++) {
 883                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 884                                          data, attr->fops))
 885                         return false;
 886         }
 887         return true;
 888 }
 889
 890 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
 891                                        struct blk_mq_ctx *ctx,
 892                                        struct dentry *hctx_dir)
 893 {
 894         struct dentry *ctx_dir;
 895         char name[20];
 896
 897         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 898         ctx_dir = debugfs_create_dir(name, hctx_dir);
 899         if (!ctx_dir)
 900                 return -ENOMEM;
 901
 902         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 903                 return -ENOMEM;
 904
 905         return 0;
 906 }
 907
 908 static int blk_mq_debugfs_register_hctx(struct request_queue *q,
 909                                         struct blk_mq_hw_ctx *hctx)
 910 {
 911         struct blk_mq_ctx *ctx;
 912         struct dentry *hctx_dir;
 913         char name[20];
 914         int i;
 915
 916         snprintf(name, sizeof(name), "%u", hctx->queue_num);
 917         hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
 918         if (!hctx_dir)
 919                 return -ENOMEM;
 920
 921         if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
 922                 return -ENOMEM;
 923
 924         hctx_for_each_ctx(hctx, ctx, i) {
 925                 if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
 926                         return -ENOMEM;
 927         }
 928
 929         return 0;
 930 }
 931
 932 int blk_mq_debugfs_register_mq(struct request_queue *q)
 933 {
 934         struct blk_mq_hw_ctx *hctx;
 935         int i;
 936
 937         if (!q->debugfs_dir)
 938                 return -ENOENT;
 939
 940         q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
 941         if (!q->mq_debugfs_dir)
 942                 goto err;
 943
 944         if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs))
 945                 goto err;
 946
 947         queue_for_each_hw_ctx(q, hctx, i) {
 948                 if (blk_mq_debugfs_register_hctx(q, hctx))
 949                         goto err;
 950         }
 951
 952         return 0;
 953
 954 err:
 955         blk_mq_debugfs_unregister_mq(q);
 956         return -ENOMEM;
 957 }
 958
 959 void blk_mq_debugfs_unregister_mq(struct request_queue *q)
 960 {
 961         debugfs_remove_recursive(q->mq_debugfs_dir);
 962         q->mq_debugfs_dir = NULL;
 963 }