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;
105 if (count >= sizeof(opbuf)) {
106 pr_err("%s: operation too long\n", __func__);
110 if (copy_from_user(opbuf, buf, count))
112 op = strstrip(opbuf);
113 if (strcmp(op, "run") == 0) {
114 blk_mq_run_hw_queues(q, true);
115 } else if (strcmp(op, "start") == 0) {
116 blk_mq_start_stopped_hw_queues(q, true);
118 pr_err("%s: unsupported operation '%s'\n", __func__, op);
120 pr_err("%s: use either 'run' or 'start'\n", __func__);
126 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
128 if (stat->nr_samples) {
129 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
130 stat->nr_samples, stat->mean, stat->min, stat->max);
132 seq_puts(m, "samples=0");
136 static int queue_poll_stat_show(void *data, struct seq_file *m)
138 struct request_queue *q = data;
141 for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
142 seq_printf(m, "read (%d Bytes): ", 1 << (9+bucket));
143 print_stat(m, &q->poll_stat[2*bucket]);
146 seq_printf(m, "write (%d Bytes): ", 1 << (9+bucket));
147 print_stat(m, &q->poll_stat[2*bucket+1]);
153 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
154 static const char *const hctx_state_name[] = {
155 HCTX_STATE_NAME(STOPPED),
156 HCTX_STATE_NAME(TAG_ACTIVE),
157 HCTX_STATE_NAME(SCHED_RESTART),
158 HCTX_STATE_NAME(TAG_WAITING),
159 HCTX_STATE_NAME(START_ON_RUN),
161 #undef HCTX_STATE_NAME
163 static int hctx_state_show(void *data, struct seq_file *m)
165 struct blk_mq_hw_ctx *hctx = data;
167 blk_flags_show(m, hctx->state, hctx_state_name,
168 ARRAY_SIZE(hctx_state_name));
173 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
174 static const char *const alloc_policy_name[] = {
175 BLK_TAG_ALLOC_NAME(FIFO),
176 BLK_TAG_ALLOC_NAME(RR),
178 #undef BLK_TAG_ALLOC_NAME
180 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
181 static const char *const hctx_flag_name[] = {
182 HCTX_FLAG_NAME(SHOULD_MERGE),
183 HCTX_FLAG_NAME(TAG_SHARED),
184 HCTX_FLAG_NAME(SG_MERGE),
185 HCTX_FLAG_NAME(BLOCKING),
186 HCTX_FLAG_NAME(NO_SCHED),
188 #undef HCTX_FLAG_NAME
190 static int hctx_flags_show(void *data, struct seq_file *m)
192 struct blk_mq_hw_ctx *hctx = data;
193 const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
195 seq_puts(m, "alloc_policy=");
196 if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
197 alloc_policy_name[alloc_policy])
198 seq_puts(m, alloc_policy_name[alloc_policy]);
200 seq_printf(m, "%d", alloc_policy);
203 hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
204 hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
209 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
210 static const char *const op_name[] = {
214 REQ_OP_NAME(DISCARD),
215 REQ_OP_NAME(ZONE_REPORT),
216 REQ_OP_NAME(SECURE_ERASE),
217 REQ_OP_NAME(ZONE_RESET),
218 REQ_OP_NAME(WRITE_SAME),
219 REQ_OP_NAME(WRITE_ZEROES),
220 REQ_OP_NAME(SCSI_IN),
221 REQ_OP_NAME(SCSI_OUT),
223 REQ_OP_NAME(DRV_OUT),
227 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
228 static const char *const cmd_flag_name[] = {
229 CMD_FLAG_NAME(FAILFAST_DEV),
230 CMD_FLAG_NAME(FAILFAST_TRANSPORT),
231 CMD_FLAG_NAME(FAILFAST_DRIVER),
235 CMD_FLAG_NAME(NOMERGE),
237 CMD_FLAG_NAME(INTEGRITY),
239 CMD_FLAG_NAME(PREFLUSH),
240 CMD_FLAG_NAME(RAHEAD),
241 CMD_FLAG_NAME(BACKGROUND),
242 CMD_FLAG_NAME(NOUNMAP),
246 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
247 static const char *const rqf_name[] = {
251 RQF_NAME(SOFTBARRIER),
253 RQF_NAME(MIXED_MERGE),
254 RQF_NAME(MQ_INFLIGHT),
266 RQF_NAME(SPECIAL_PAYLOAD),
270 static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
272 struct request *rq = list_entry_rq(v);
273 const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
274 const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
276 seq_printf(m, "%p {.op=", rq);
277 if (op < ARRAY_SIZE(op_name) && op_name[op])
278 seq_printf(m, "%s", op_name[op]);
280 seq_printf(m, "%d", op);
281 seq_puts(m, ", .cmd_flags=");
282 blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
283 ARRAY_SIZE(cmd_flag_name));
284 seq_puts(m, ", .rq_flags=");
285 blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
286 ARRAY_SIZE(rqf_name));
287 seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
290 mq_ops->show_rq(m, rq);
295 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
296 __acquires(&hctx->lock)
298 struct blk_mq_hw_ctx *hctx = m->private;
300 spin_lock(&hctx->lock);
301 return seq_list_start(&hctx->dispatch, *pos);
304 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
306 struct blk_mq_hw_ctx *hctx = m->private;
308 return seq_list_next(v, &hctx->dispatch, pos);
311 static void hctx_dispatch_stop(struct seq_file *m, void *v)
312 __releases(&hctx->lock)
314 struct blk_mq_hw_ctx *hctx = m->private;
316 spin_unlock(&hctx->lock);
319 static const struct seq_operations hctx_dispatch_seq_ops = {
320 .start = hctx_dispatch_start,
321 .next = hctx_dispatch_next,
322 .stop = hctx_dispatch_stop,
323 .show = blk_mq_debugfs_rq_show,
326 static int hctx_ctx_map_show(void *data, struct seq_file *m)
328 struct blk_mq_hw_ctx *hctx = data;
330 sbitmap_bitmap_show(&hctx->ctx_map, m);
334 static void blk_mq_debugfs_tags_show(struct seq_file *m,
335 struct blk_mq_tags *tags)
337 seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
338 seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
339 seq_printf(m, "active_queues=%d\n",
340 atomic_read(&tags->active_queues));
342 seq_puts(m, "\nbitmap_tags:\n");
343 sbitmap_queue_show(&tags->bitmap_tags, m);
345 if (tags->nr_reserved_tags) {
346 seq_puts(m, "\nbreserved_tags:\n");
347 sbitmap_queue_show(&tags->breserved_tags, m);
351 static int hctx_tags_show(void *data, struct seq_file *m)
353 struct blk_mq_hw_ctx *hctx = data;
354 struct request_queue *q = hctx->queue;
357 res = mutex_lock_interruptible(&q->sysfs_lock);
361 blk_mq_debugfs_tags_show(m, hctx->tags);
362 mutex_unlock(&q->sysfs_lock);
368 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
370 struct blk_mq_hw_ctx *hctx = data;
371 struct request_queue *q = hctx->queue;
374 res = mutex_lock_interruptible(&q->sysfs_lock);
378 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
379 mutex_unlock(&q->sysfs_lock);
385 static int hctx_sched_tags_show(void *data, struct seq_file *m)
387 struct blk_mq_hw_ctx *hctx = data;
388 struct request_queue *q = hctx->queue;
391 res = mutex_lock_interruptible(&q->sysfs_lock);
394 if (hctx->sched_tags)
395 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
396 mutex_unlock(&q->sysfs_lock);
402 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
404 struct blk_mq_hw_ctx *hctx = data;
405 struct request_queue *q = hctx->queue;
408 res = mutex_lock_interruptible(&q->sysfs_lock);
411 if (hctx->sched_tags)
412 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
413 mutex_unlock(&q->sysfs_lock);
419 static int hctx_io_poll_show(void *data, struct seq_file *m)
421 struct blk_mq_hw_ctx *hctx = data;
423 seq_printf(m, "considered=%lu\n", hctx->poll_considered);
424 seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
425 seq_printf(m, "success=%lu\n", hctx->poll_success);
429 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
430 size_t count, loff_t *ppos)
432 struct blk_mq_hw_ctx *hctx = data;
434 hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
438 static int hctx_dispatched_show(void *data, struct seq_file *m)
440 struct blk_mq_hw_ctx *hctx = data;
443 seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
445 for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
446 unsigned int d = 1U << (i - 1);
448 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
451 seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
455 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
456 size_t count, loff_t *ppos)
458 struct blk_mq_hw_ctx *hctx = data;
461 for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
462 hctx->dispatched[i] = 0;
466 static int hctx_queued_show(void *data, struct seq_file *m)
468 struct blk_mq_hw_ctx *hctx = data;
470 seq_printf(m, "%lu\n", hctx->queued);
474 static ssize_t hctx_queued_write(void *data, const char __user *buf,
475 size_t count, loff_t *ppos)
477 struct blk_mq_hw_ctx *hctx = data;
483 static int hctx_run_show(void *data, struct seq_file *m)
485 struct blk_mq_hw_ctx *hctx = data;
487 seq_printf(m, "%lu\n", hctx->run);
491 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
494 struct blk_mq_hw_ctx *hctx = data;
500 static int hctx_active_show(void *data, struct seq_file *m)
502 struct blk_mq_hw_ctx *hctx = data;
504 seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
508 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
509 __acquires(&ctx->lock)
511 struct blk_mq_ctx *ctx = m->private;
513 spin_lock(&ctx->lock);
514 return seq_list_start(&ctx->rq_list, *pos);
517 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
519 struct blk_mq_ctx *ctx = m->private;
521 return seq_list_next(v, &ctx->rq_list, pos);
524 static void ctx_rq_list_stop(struct seq_file *m, void *v)
525 __releases(&ctx->lock)
527 struct blk_mq_ctx *ctx = m->private;
529 spin_unlock(&ctx->lock);
532 static const struct seq_operations ctx_rq_list_seq_ops = {
533 .start = ctx_rq_list_start,
534 .next = ctx_rq_list_next,
535 .stop = ctx_rq_list_stop,
536 .show = blk_mq_debugfs_rq_show,
538 static int ctx_dispatched_show(void *data, struct seq_file *m)
540 struct blk_mq_ctx *ctx = data;
542 seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
546 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
547 size_t count, loff_t *ppos)
549 struct blk_mq_ctx *ctx = data;
551 ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
555 static int ctx_merged_show(void *data, struct seq_file *m)
557 struct blk_mq_ctx *ctx = data;
559 seq_printf(m, "%lu\n", ctx->rq_merged);
563 static ssize_t ctx_merged_write(void *data, const char __user *buf,
564 size_t count, loff_t *ppos)
566 struct blk_mq_ctx *ctx = data;
572 static int ctx_completed_show(void *data, struct seq_file *m)
574 struct blk_mq_ctx *ctx = data;
576 seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
580 static ssize_t ctx_completed_write(void *data, const char __user *buf,
581 size_t count, loff_t *ppos)
583 struct blk_mq_ctx *ctx = data;
585 ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
589 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
591 const struct blk_mq_debugfs_attr *attr = m->private;
592 void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
594 return attr->show(data, m);
597 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
598 size_t count, loff_t *ppos)
600 struct seq_file *m = file->private_data;
601 const struct blk_mq_debugfs_attr *attr = m->private;
602 void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
607 return attr->write(data, buf, count, ppos);
610 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
612 const struct blk_mq_debugfs_attr *attr = inode->i_private;
613 void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
618 ret = seq_open(file, attr->seq_ops);
620 m = file->private_data;
626 if (WARN_ON_ONCE(!attr->show))
629 return single_open(file, blk_mq_debugfs_show, inode->i_private);
632 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
634 const struct blk_mq_debugfs_attr *attr = inode->i_private;
637 return single_release(inode, file);
639 return seq_release(inode, file);
642 const struct file_operations blk_mq_debugfs_fops = {
643 .open = blk_mq_debugfs_open,
645 .write = blk_mq_debugfs_write,
647 .release = blk_mq_debugfs_release,
650 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
651 {"poll_stat", 0400, queue_poll_stat_show},
652 {"state", 0600, queue_state_show, queue_state_write},
656 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
657 {"state", 0400, hctx_state_show},
658 {"flags", 0400, hctx_flags_show},
659 {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
660 {"ctx_map", 0400, hctx_ctx_map_show},
661 {"tags", 0400, hctx_tags_show},
662 {"tags_bitmap", 0400, hctx_tags_bitmap_show},
663 {"sched_tags", 0400, hctx_sched_tags_show},
664 {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
665 {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
666 {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
667 {"queued", 0600, hctx_queued_show, hctx_queued_write},
668 {"run", 0600, hctx_run_show, hctx_run_write},
669 {"active", 0400, hctx_active_show},
673 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
674 {"rq_list", 0400, .seq_ops = &ctx_rq_list_seq_ops},
675 {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
676 {"merged", 0600, ctx_merged_show, ctx_merged_write},
677 {"completed", 0600, ctx_completed_show, ctx_completed_write},
681 int blk_mq_debugfs_register(struct request_queue *q)
683 if (!blk_debugfs_root)
686 q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
691 if (blk_mq_debugfs_register_mq(q))
697 blk_mq_debugfs_unregister(q);
701 void blk_mq_debugfs_unregister(struct request_queue *q)
703 debugfs_remove_recursive(q->debugfs_dir);
704 q->mq_debugfs_dir = NULL;
705 q->debugfs_dir = NULL;
708 static bool debugfs_create_files(struct dentry *parent, void *data,
709 const struct blk_mq_debugfs_attr *attr)
711 d_inode(parent)->i_private = data;
713 for (; attr->name; attr++) {
714 if (!debugfs_create_file(attr->name, attr->mode, parent,
715 (void *)attr, &blk_mq_debugfs_fops))
721 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
722 struct blk_mq_ctx *ctx,
723 struct dentry *hctx_dir)
725 struct dentry *ctx_dir;
728 snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
729 ctx_dir = debugfs_create_dir(name, hctx_dir);
733 if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
739 static int blk_mq_debugfs_register_hctx(struct request_queue *q,
740 struct blk_mq_hw_ctx *hctx)
742 struct blk_mq_ctx *ctx;
743 struct dentry *hctx_dir;
747 snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
748 hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
752 if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
755 hctx_for_each_ctx(hctx, ctx, i) {
756 if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
763 int blk_mq_debugfs_register_mq(struct request_queue *q)
765 struct blk_mq_hw_ctx *hctx;
771 q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
772 if (!q->mq_debugfs_dir)
775 if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs))
778 queue_for_each_hw_ctx(q, hctx, i) {
779 if (blk_mq_debugfs_register_hctx(q, hctx))
786 blk_mq_debugfs_unregister_mq(q);
790 void blk_mq_debugfs_unregister_mq(struct request_queue *q)
792 debugfs_remove_recursive(q->mq_debugfs_dir);
793 q->mq_debugfs_dir = NULL;