2 * Copyright (C) 2017 Facebook
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.
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.
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/>.
17 #include <linux/kernel.h>
18 #include <linux/blkdev.h>
19 #include <linux/debugfs.h>
21 #include <linux/blk-mq.h>
24 #include "blk-mq-tag.h"
26 struct blk_mq_debugfs_attr {
29 int (*show)(void *, struct seq_file *);
30 ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
31 /* Set either .show or .seq_ops. */
32 const struct seq_operations *seq_ops;
35 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
36 const char *const *flag_name, int flag_name_count)
41 for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
42 if (!(flags & BIT(i)))
47 if (i < flag_name_count && flag_name[i])
48 seq_puts(m, flag_name[i]);
50 seq_printf(m, "%d", i);
55 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
56 static const char *const blk_queue_flag_name[] = {
57 QUEUE_FLAG_NAME(QUEUED),
58 QUEUE_FLAG_NAME(STOPPED),
59 QUEUE_FLAG_NAME(SYNCFULL),
60 QUEUE_FLAG_NAME(ASYNCFULL),
61 QUEUE_FLAG_NAME(DYING),
62 QUEUE_FLAG_NAME(BYPASS),
63 QUEUE_FLAG_NAME(BIDI),
64 QUEUE_FLAG_NAME(NOMERGES),
65 QUEUE_FLAG_NAME(SAME_COMP),
66 QUEUE_FLAG_NAME(FAIL_IO),
67 QUEUE_FLAG_NAME(STACKABLE),
68 QUEUE_FLAG_NAME(NONROT),
69 QUEUE_FLAG_NAME(IO_STAT),
70 QUEUE_FLAG_NAME(DISCARD),
71 QUEUE_FLAG_NAME(NOXMERGES),
72 QUEUE_FLAG_NAME(ADD_RANDOM),
73 QUEUE_FLAG_NAME(SECERASE),
74 QUEUE_FLAG_NAME(SAME_FORCE),
75 QUEUE_FLAG_NAME(DEAD),
76 QUEUE_FLAG_NAME(INIT_DONE),
77 QUEUE_FLAG_NAME(NO_SG_MERGE),
78 QUEUE_FLAG_NAME(POLL),
81 QUEUE_FLAG_NAME(FLUSH_NQ),
83 QUEUE_FLAG_NAME(STATS),
84 QUEUE_FLAG_NAME(POLL_STATS),
85 QUEUE_FLAG_NAME(REGISTERED),
87 #undef QUEUE_FLAG_NAME
89 static int queue_state_show(void *data, struct seq_file *m)
91 struct request_queue *q = data;
93 blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
94 ARRAY_SIZE(blk_queue_flag_name));
99 static ssize_t queue_state_write(void *data, const char __user *buf,
100 size_t count, loff_t *ppos)
102 struct request_queue *q = data;
103 char opbuf[16] = { }, *op;
106 * The "state" attribute is removed after blk_cleanup_queue() has called
107 * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
108 * triggering a use-after-free.
110 if (blk_queue_dead(q))
113 if (count >= sizeof(opbuf)) {
114 pr_err("%s: operation too long\n", __func__);
118 if (copy_from_user(opbuf, buf, count))
120 op = strstrip(opbuf);
121 if (strcmp(op, "run") == 0) {
122 blk_mq_run_hw_queues(q, true);
123 } else if (strcmp(op, "start") == 0) {
124 blk_mq_start_stopped_hw_queues(q, true);
126 pr_err("%s: unsupported operation '%s'\n", __func__, op);
128 pr_err("%s: use either 'run' or 'start'\n", __func__);
134 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
136 if (stat->nr_samples) {
137 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
138 stat->nr_samples, stat->mean, stat->min, stat->max);
140 seq_puts(m, "samples=0");
144 static int queue_poll_stat_show(void *data, struct seq_file *m)
146 struct request_queue *q = data;
149 for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
150 seq_printf(m, "read (%d Bytes): ", 1 << (9+bucket));
151 print_stat(m, &q->poll_stat[2*bucket]);
154 seq_printf(m, "write (%d Bytes): ", 1 << (9+bucket));
155 print_stat(m, &q->poll_stat[2*bucket+1]);
161 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
162 static const char *const hctx_state_name[] = {
163 HCTX_STATE_NAME(STOPPED),
164 HCTX_STATE_NAME(TAG_ACTIVE),
165 HCTX_STATE_NAME(SCHED_RESTART),
166 HCTX_STATE_NAME(TAG_WAITING),
167 HCTX_STATE_NAME(START_ON_RUN),
169 #undef HCTX_STATE_NAME
171 static int hctx_state_show(void *data, struct seq_file *m)
173 struct blk_mq_hw_ctx *hctx = data;
175 blk_flags_show(m, hctx->state, hctx_state_name,
176 ARRAY_SIZE(hctx_state_name));
181 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
182 static const char *const alloc_policy_name[] = {
183 BLK_TAG_ALLOC_NAME(FIFO),
184 BLK_TAG_ALLOC_NAME(RR),
186 #undef BLK_TAG_ALLOC_NAME
188 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
189 static const char *const hctx_flag_name[] = {
190 HCTX_FLAG_NAME(SHOULD_MERGE),
191 HCTX_FLAG_NAME(TAG_SHARED),
192 HCTX_FLAG_NAME(SG_MERGE),
193 HCTX_FLAG_NAME(BLOCKING),
194 HCTX_FLAG_NAME(NO_SCHED),
196 #undef HCTX_FLAG_NAME
198 static int hctx_flags_show(void *data, struct seq_file *m)
200 struct blk_mq_hw_ctx *hctx = data;
201 const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
203 seq_puts(m, "alloc_policy=");
204 if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
205 alloc_policy_name[alloc_policy])
206 seq_puts(m, alloc_policy_name[alloc_policy]);
208 seq_printf(m, "%d", alloc_policy);
211 hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
212 hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
217 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
218 static const char *const op_name[] = {
222 REQ_OP_NAME(DISCARD),
223 REQ_OP_NAME(ZONE_REPORT),
224 REQ_OP_NAME(SECURE_ERASE),
225 REQ_OP_NAME(ZONE_RESET),
226 REQ_OP_NAME(WRITE_SAME),
227 REQ_OP_NAME(WRITE_ZEROES),
228 REQ_OP_NAME(SCSI_IN),
229 REQ_OP_NAME(SCSI_OUT),
231 REQ_OP_NAME(DRV_OUT),
235 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
236 static const char *const cmd_flag_name[] = {
237 CMD_FLAG_NAME(FAILFAST_DEV),
238 CMD_FLAG_NAME(FAILFAST_TRANSPORT),
239 CMD_FLAG_NAME(FAILFAST_DRIVER),
243 CMD_FLAG_NAME(NOMERGE),
245 CMD_FLAG_NAME(INTEGRITY),
247 CMD_FLAG_NAME(PREFLUSH),
248 CMD_FLAG_NAME(RAHEAD),
249 CMD_FLAG_NAME(BACKGROUND),
250 CMD_FLAG_NAME(NOUNMAP),
254 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
255 static const char *const rqf_name[] = {
259 RQF_NAME(SOFTBARRIER),
261 RQF_NAME(MIXED_MERGE),
262 RQF_NAME(MQ_INFLIGHT),
274 RQF_NAME(SPECIAL_PAYLOAD),
278 static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
280 struct request *rq = list_entry_rq(v);
281 const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
282 const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
284 seq_printf(m, "%p {.op=", rq);
285 if (op < ARRAY_SIZE(op_name) && op_name[op])
286 seq_printf(m, "%s", op_name[op]);
288 seq_printf(m, "%d", op);
289 seq_puts(m, ", .cmd_flags=");
290 blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
291 ARRAY_SIZE(cmd_flag_name));
292 seq_puts(m, ", .rq_flags=");
293 blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
294 ARRAY_SIZE(rqf_name));
295 seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
298 mq_ops->show_rq(m, rq);
303 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
304 __acquires(&hctx->lock)
306 struct blk_mq_hw_ctx *hctx = m->private;
308 spin_lock(&hctx->lock);
309 return seq_list_start(&hctx->dispatch, *pos);
312 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
314 struct blk_mq_hw_ctx *hctx = m->private;
316 return seq_list_next(v, &hctx->dispatch, pos);
319 static void hctx_dispatch_stop(struct seq_file *m, void *v)
320 __releases(&hctx->lock)
322 struct blk_mq_hw_ctx *hctx = m->private;
324 spin_unlock(&hctx->lock);
327 static const struct seq_operations hctx_dispatch_seq_ops = {
328 .start = hctx_dispatch_start,
329 .next = hctx_dispatch_next,
330 .stop = hctx_dispatch_stop,
331 .show = blk_mq_debugfs_rq_show,
334 static int hctx_ctx_map_show(void *data, struct seq_file *m)
336 struct blk_mq_hw_ctx *hctx = data;
338 sbitmap_bitmap_show(&hctx->ctx_map, m);
342 static void blk_mq_debugfs_tags_show(struct seq_file *m,
343 struct blk_mq_tags *tags)
345 seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
346 seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
347 seq_printf(m, "active_queues=%d\n",
348 atomic_read(&tags->active_queues));
350 seq_puts(m, "\nbitmap_tags:\n");
351 sbitmap_queue_show(&tags->bitmap_tags, m);
353 if (tags->nr_reserved_tags) {
354 seq_puts(m, "\nbreserved_tags:\n");
355 sbitmap_queue_show(&tags->breserved_tags, m);
359 static int hctx_tags_show(void *data, struct seq_file *m)
361 struct blk_mq_hw_ctx *hctx = data;
362 struct request_queue *q = hctx->queue;
365 res = mutex_lock_interruptible(&q->sysfs_lock);
369 blk_mq_debugfs_tags_show(m, hctx->tags);
370 mutex_unlock(&q->sysfs_lock);
376 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
378 struct blk_mq_hw_ctx *hctx = data;
379 struct request_queue *q = hctx->queue;
382 res = mutex_lock_interruptible(&q->sysfs_lock);
386 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
387 mutex_unlock(&q->sysfs_lock);
393 static int hctx_sched_tags_show(void *data, struct seq_file *m)
395 struct blk_mq_hw_ctx *hctx = data;
396 struct request_queue *q = hctx->queue;
399 res = mutex_lock_interruptible(&q->sysfs_lock);
402 if (hctx->sched_tags)
403 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
404 mutex_unlock(&q->sysfs_lock);
410 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
412 struct blk_mq_hw_ctx *hctx = data;
413 struct request_queue *q = hctx->queue;
416 res = mutex_lock_interruptible(&q->sysfs_lock);
419 if (hctx->sched_tags)
420 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
421 mutex_unlock(&q->sysfs_lock);
427 static int hctx_io_poll_show(void *data, struct seq_file *m)
429 struct blk_mq_hw_ctx *hctx = data;
431 seq_printf(m, "considered=%lu\n", hctx->poll_considered);
432 seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
433 seq_printf(m, "success=%lu\n", hctx->poll_success);
437 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
438 size_t count, loff_t *ppos)
440 struct blk_mq_hw_ctx *hctx = data;
442 hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
446 static int hctx_dispatched_show(void *data, struct seq_file *m)
448 struct blk_mq_hw_ctx *hctx = data;
451 seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
453 for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
454 unsigned int d = 1U << (i - 1);
456 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
459 seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
463 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
464 size_t count, loff_t *ppos)
466 struct blk_mq_hw_ctx *hctx = data;
469 for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
470 hctx->dispatched[i] = 0;
474 static int hctx_queued_show(void *data, struct seq_file *m)
476 struct blk_mq_hw_ctx *hctx = data;
478 seq_printf(m, "%lu\n", hctx->queued);
482 static ssize_t hctx_queued_write(void *data, const char __user *buf,
483 size_t count, loff_t *ppos)
485 struct blk_mq_hw_ctx *hctx = data;
491 static int hctx_run_show(void *data, struct seq_file *m)
493 struct blk_mq_hw_ctx *hctx = data;
495 seq_printf(m, "%lu\n", hctx->run);
499 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
502 struct blk_mq_hw_ctx *hctx = data;
508 static int hctx_active_show(void *data, struct seq_file *m)
510 struct blk_mq_hw_ctx *hctx = data;
512 seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
516 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
517 __acquires(&ctx->lock)
519 struct blk_mq_ctx *ctx = m->private;
521 spin_lock(&ctx->lock);
522 return seq_list_start(&ctx->rq_list, *pos);
525 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
527 struct blk_mq_ctx *ctx = m->private;
529 return seq_list_next(v, &ctx->rq_list, pos);
532 static void ctx_rq_list_stop(struct seq_file *m, void *v)
533 __releases(&ctx->lock)
535 struct blk_mq_ctx *ctx = m->private;
537 spin_unlock(&ctx->lock);
540 static const struct seq_operations ctx_rq_list_seq_ops = {
541 .start = ctx_rq_list_start,
542 .next = ctx_rq_list_next,
543 .stop = ctx_rq_list_stop,
544 .show = blk_mq_debugfs_rq_show,
546 static int ctx_dispatched_show(void *data, struct seq_file *m)
548 struct blk_mq_ctx *ctx = data;
550 seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
554 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
555 size_t count, loff_t *ppos)
557 struct blk_mq_ctx *ctx = data;
559 ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
563 static int ctx_merged_show(void *data, struct seq_file *m)
565 struct blk_mq_ctx *ctx = data;
567 seq_printf(m, "%lu\n", ctx->rq_merged);
571 static ssize_t ctx_merged_write(void *data, const char __user *buf,
572 size_t count, loff_t *ppos)
574 struct blk_mq_ctx *ctx = data;
580 static int ctx_completed_show(void *data, struct seq_file *m)
582 struct blk_mq_ctx *ctx = data;
584 seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
588 static ssize_t ctx_completed_write(void *data, const char __user *buf,
589 size_t count, loff_t *ppos)
591 struct blk_mq_ctx *ctx = data;
593 ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
597 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
599 const struct blk_mq_debugfs_attr *attr = m->private;
600 void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
602 return attr->show(data, m);
605 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
606 size_t count, loff_t *ppos)
608 struct seq_file *m = file->private_data;
609 const struct blk_mq_debugfs_attr *attr = m->private;
610 void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
615 return attr->write(data, buf, count, ppos);
618 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
620 const struct blk_mq_debugfs_attr *attr = inode->i_private;
621 void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
626 ret = seq_open(file, attr->seq_ops);
628 m = file->private_data;
634 if (WARN_ON_ONCE(!attr->show))
637 return single_open(file, blk_mq_debugfs_show, inode->i_private);
640 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
642 const struct blk_mq_debugfs_attr *attr = inode->i_private;
645 return single_release(inode, file);
647 return seq_release(inode, file);
650 const struct file_operations blk_mq_debugfs_fops = {
651 .open = blk_mq_debugfs_open,
653 .write = blk_mq_debugfs_write,
655 .release = blk_mq_debugfs_release,
658 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
659 {"poll_stat", 0400, queue_poll_stat_show},
660 {"state", 0600, queue_state_show, queue_state_write},
664 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
665 {"state", 0400, hctx_state_show},
666 {"flags", 0400, hctx_flags_show},
667 {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
668 {"ctx_map", 0400, hctx_ctx_map_show},
669 {"tags", 0400, hctx_tags_show},
670 {"tags_bitmap", 0400, hctx_tags_bitmap_show},
671 {"sched_tags", 0400, hctx_sched_tags_show},
672 {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
673 {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
674 {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
675 {"queued", 0600, hctx_queued_show, hctx_queued_write},
676 {"run", 0600, hctx_run_show, hctx_run_write},
677 {"active", 0400, hctx_active_show},
681 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
682 {"rq_list", 0400, .seq_ops = &ctx_rq_list_seq_ops},
683 {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
684 {"merged", 0600, ctx_merged_show, ctx_merged_write},
685 {"completed", 0600, ctx_completed_show, ctx_completed_write},
689 int blk_mq_debugfs_register(struct request_queue *q)
691 if (!blk_debugfs_root)
694 q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
699 if (blk_mq_debugfs_register_mq(q))
705 blk_mq_debugfs_unregister(q);
709 void blk_mq_debugfs_unregister(struct request_queue *q)
711 debugfs_remove_recursive(q->debugfs_dir);
712 q->mq_debugfs_dir = NULL;
713 q->debugfs_dir = NULL;
716 static bool debugfs_create_files(struct dentry *parent, void *data,
717 const struct blk_mq_debugfs_attr *attr)
719 d_inode(parent)->i_private = data;
721 for (; attr->name; attr++) {
722 if (!debugfs_create_file(attr->name, attr->mode, parent,
723 (void *)attr, &blk_mq_debugfs_fops))
729 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
730 struct blk_mq_ctx *ctx,
731 struct dentry *hctx_dir)
733 struct dentry *ctx_dir;
736 snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
737 ctx_dir = debugfs_create_dir(name, hctx_dir);
741 if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
747 static int blk_mq_debugfs_register_hctx(struct request_queue *q,
748 struct blk_mq_hw_ctx *hctx)
750 struct blk_mq_ctx *ctx;
751 struct dentry *hctx_dir;
755 snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
756 hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
760 if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
763 hctx_for_each_ctx(hctx, ctx, i) {
764 if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
771 int blk_mq_debugfs_register_mq(struct request_queue *q)
773 struct blk_mq_hw_ctx *hctx;
779 q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
780 if (!q->mq_debugfs_dir)
783 if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs))
786 queue_for_each_hw_ctx(q, hctx, i) {
787 if (blk_mq_debugfs_register_hctx(q, hctx))
794 blk_mq_debugfs_unregister_mq(q);
798 void blk_mq_debugfs_unregister_mq(struct request_queue *q)
800 debugfs_remove_recursive(q->mq_debugfs_dir);
801 q->mq_debugfs_dir = NULL;