blk-mq-debugfs.c 22.0 KB
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/*
 * Copyright (C) 2017 Facebook
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/debugfs.h>

#include <linux/blk-mq.h>
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#include "blk.h"
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#include "blk-mq.h"
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#include "blk-mq-debugfs.h"
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#include "blk-mq-tag.h"
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static int blk_flags_show(struct seq_file *m, const unsigned long flags,
			  const char *const *flag_name, int flag_name_count)
{
	bool sep = false;
	int i;

	for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
		if (!(flags & BIT(i)))
			continue;
		if (sep)
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			seq_puts(m, "|");
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		sep = true;
		if (i < flag_name_count && flag_name[i])
			seq_puts(m, flag_name[i]);
		else
			seq_printf(m, "%d", i);
	}
	return 0;
}

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#define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
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static const char *const blk_queue_flag_name[] = {
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	QUEUE_FLAG_NAME(QUEUED),
	QUEUE_FLAG_NAME(STOPPED),
	QUEUE_FLAG_NAME(SYNCFULL),
	QUEUE_FLAG_NAME(ASYNCFULL),
	QUEUE_FLAG_NAME(DYING),
	QUEUE_FLAG_NAME(BYPASS),
	QUEUE_FLAG_NAME(BIDI),
	QUEUE_FLAG_NAME(NOMERGES),
	QUEUE_FLAG_NAME(SAME_COMP),
	QUEUE_FLAG_NAME(FAIL_IO),
	QUEUE_FLAG_NAME(STACKABLE),
	QUEUE_FLAG_NAME(NONROT),
	QUEUE_FLAG_NAME(IO_STAT),
	QUEUE_FLAG_NAME(DISCARD),
	QUEUE_FLAG_NAME(NOXMERGES),
	QUEUE_FLAG_NAME(ADD_RANDOM),
	QUEUE_FLAG_NAME(SECERASE),
	QUEUE_FLAG_NAME(SAME_FORCE),
	QUEUE_FLAG_NAME(DEAD),
	QUEUE_FLAG_NAME(INIT_DONE),
	QUEUE_FLAG_NAME(NO_SG_MERGE),
	QUEUE_FLAG_NAME(POLL),
	QUEUE_FLAG_NAME(WC),
	QUEUE_FLAG_NAME(FUA),
	QUEUE_FLAG_NAME(FLUSH_NQ),
	QUEUE_FLAG_NAME(DAX),
	QUEUE_FLAG_NAME(STATS),
	QUEUE_FLAG_NAME(POLL_STATS),
	QUEUE_FLAG_NAME(REGISTERED),
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};
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#undef QUEUE_FLAG_NAME
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static int queue_state_show(void *data, struct seq_file *m)
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{
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	struct request_queue *q = data;
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	blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
		       ARRAY_SIZE(blk_queue_flag_name));
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	seq_puts(m, "\n");
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	return 0;
}

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static ssize_t queue_state_write(void *data, const char __user *buf,
				 size_t count, loff_t *ppos)
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{
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	struct request_queue *q = data;
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	char opbuf[16] = { }, *op;
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	/*
	 * The "state" attribute is removed after blk_cleanup_queue() has called
	 * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
	 * triggering a use-after-free.
	 */
	if (blk_queue_dead(q))
		return -ENOENT;

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	if (count >= sizeof(opbuf)) {
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		pr_err("%s: operation too long\n", __func__);
		goto inval;
	}

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	if (copy_from_user(opbuf, buf, count))
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		return -EFAULT;
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	op = strstrip(opbuf);
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	if (strcmp(op, "run") == 0) {
		blk_mq_run_hw_queues(q, true);
	} else if (strcmp(op, "start") == 0) {
		blk_mq_start_stopped_hw_queues(q, true);
	} else {
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		pr_err("%s: unsupported operation '%s'\n", __func__, op);
inval:
		pr_err("%s: use either 'run' or 'start'\n", __func__);
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		return -EINVAL;
	}
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	return count;
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}

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static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
{
	if (stat->nr_samples) {
		seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
			   stat->nr_samples, stat->mean, stat->min, stat->max);
	} else {
		seq_puts(m, "samples=0");
	}
}

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static int queue_poll_stat_show(void *data, struct seq_file *m)
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{
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	struct request_queue *q = data;
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	int bucket;
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	for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
		seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
		print_stat(m, &q->poll_stat[2*bucket]);
		seq_puts(m, "\n");
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		seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
		print_stat(m, &q->poll_stat[2*bucket+1]);
		seq_puts(m, "\n");
	}
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	return 0;
}

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#define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
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static const char *const hctx_state_name[] = {
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	HCTX_STATE_NAME(STOPPED),
	HCTX_STATE_NAME(TAG_ACTIVE),
	HCTX_STATE_NAME(SCHED_RESTART),
	HCTX_STATE_NAME(TAG_WAITING),
	HCTX_STATE_NAME(START_ON_RUN),
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};
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#undef HCTX_STATE_NAME

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static int hctx_state_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	blk_flags_show(m, hctx->state, hctx_state_name,
		       ARRAY_SIZE(hctx_state_name));
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	seq_puts(m, "\n");
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	return 0;
}

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#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
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static const char *const alloc_policy_name[] = {
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	BLK_TAG_ALLOC_NAME(FIFO),
	BLK_TAG_ALLOC_NAME(RR),
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};
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#undef BLK_TAG_ALLOC_NAME
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#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
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static const char *const hctx_flag_name[] = {
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	HCTX_FLAG_NAME(SHOULD_MERGE),
	HCTX_FLAG_NAME(TAG_SHARED),
	HCTX_FLAG_NAME(SG_MERGE),
	HCTX_FLAG_NAME(BLOCKING),
	HCTX_FLAG_NAME(NO_SCHED),
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};
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#undef HCTX_FLAG_NAME
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static int hctx_flags_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
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	seq_puts(m, "alloc_policy=");
	if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
	    alloc_policy_name[alloc_policy])
		seq_puts(m, alloc_policy_name[alloc_policy]);
	else
		seq_printf(m, "%d", alloc_policy);
	seq_puts(m, " ");
	blk_flags_show(m,
		       hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
		       hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
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	seq_puts(m, "\n");
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	return 0;
}

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#define REQ_OP_NAME(name) [REQ_OP_##name] = #name
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static const char *const op_name[] = {
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	REQ_OP_NAME(READ),
	REQ_OP_NAME(WRITE),
	REQ_OP_NAME(FLUSH),
	REQ_OP_NAME(DISCARD),
	REQ_OP_NAME(ZONE_REPORT),
	REQ_OP_NAME(SECURE_ERASE),
	REQ_OP_NAME(ZONE_RESET),
	REQ_OP_NAME(WRITE_SAME),
	REQ_OP_NAME(WRITE_ZEROES),
	REQ_OP_NAME(SCSI_IN),
	REQ_OP_NAME(SCSI_OUT),
	REQ_OP_NAME(DRV_IN),
	REQ_OP_NAME(DRV_OUT),
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};
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#undef REQ_OP_NAME
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#define CMD_FLAG_NAME(name) [__REQ_##name] = #name
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static const char *const cmd_flag_name[] = {
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	CMD_FLAG_NAME(FAILFAST_DEV),
	CMD_FLAG_NAME(FAILFAST_TRANSPORT),
	CMD_FLAG_NAME(FAILFAST_DRIVER),
	CMD_FLAG_NAME(SYNC),
	CMD_FLAG_NAME(META),
	CMD_FLAG_NAME(PRIO),
	CMD_FLAG_NAME(NOMERGE),
	CMD_FLAG_NAME(IDLE),
	CMD_FLAG_NAME(INTEGRITY),
	CMD_FLAG_NAME(FUA),
	CMD_FLAG_NAME(PREFLUSH),
	CMD_FLAG_NAME(RAHEAD),
	CMD_FLAG_NAME(BACKGROUND),
	CMD_FLAG_NAME(NOUNMAP),
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};
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#undef CMD_FLAG_NAME
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#define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
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static const char *const rqf_name[] = {
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	RQF_NAME(SORTED),
	RQF_NAME(STARTED),
	RQF_NAME(QUEUED),
	RQF_NAME(SOFTBARRIER),
	RQF_NAME(FLUSH_SEQ),
	RQF_NAME(MIXED_MERGE),
	RQF_NAME(MQ_INFLIGHT),
	RQF_NAME(DONTPREP),
	RQF_NAME(PREEMPT),
	RQF_NAME(COPY_USER),
	RQF_NAME(FAILED),
	RQF_NAME(QUIET),
	RQF_NAME(ELVPRIV),
	RQF_NAME(IO_STAT),
	RQF_NAME(ALLOCED),
	RQF_NAME(PM),
	RQF_NAME(HASHED),
	RQF_NAME(STATS),
	RQF_NAME(SPECIAL_PAYLOAD),
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};
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#undef RQF_NAME
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#define RQAF_NAME(name) [REQ_ATOM_##name] = #name
static const char *const rqaf_name[] = {
	RQAF_NAME(COMPLETE),
	RQAF_NAME(STARTED),
	RQAF_NAME(POLL_SLEPT),
};
#undef RQAF_NAME

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int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
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{
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	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
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	const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
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	seq_printf(m, "%p {.op=", rq);
	if (op < ARRAY_SIZE(op_name) && op_name[op])
		seq_printf(m, "%s", op_name[op]);
	else
		seq_printf(m, "%d", op);
	seq_puts(m, ", .cmd_flags=");
	blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
		       ARRAY_SIZE(cmd_flag_name));
	seq_puts(m, ", .rq_flags=");
	blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
		       ARRAY_SIZE(rqf_name));
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	seq_puts(m, ", .atomic_flags=");
	blk_flags_show(m, rq->atomic_flags, rqaf_name, ARRAY_SIZE(rqaf_name));
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	seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
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		   rq->internal_tag);
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	if (mq_ops->show_rq)
		mq_ops->show_rq(m, rq);
	seq_puts(m, "}\n");
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	return 0;
}
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EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);

int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
{
	return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
}
O
Omar Sandoval 已提交
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EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
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static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
	__acquires(&q->requeue_lock)
{
	struct request_queue *q = m->private;

	spin_lock_irq(&q->requeue_lock);
	return seq_list_start(&q->requeue_list, *pos);
}

static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct request_queue *q = m->private;

	return seq_list_next(v, &q->requeue_list, pos);
}

static void queue_requeue_list_stop(struct seq_file *m, void *v)
	__releases(&q->requeue_lock)
{
	struct request_queue *q = m->private;

	spin_unlock_irq(&q->requeue_lock);
}

static const struct seq_operations queue_requeue_list_seq_ops = {
	.start	= queue_requeue_list_start,
	.next	= queue_requeue_list_next,
	.stop	= queue_requeue_list_stop,
	.show	= blk_mq_debugfs_rq_show,
};

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static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
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	__acquires(&hctx->lock)
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{
	struct blk_mq_hw_ctx *hctx = m->private;

	spin_lock(&hctx->lock);
	return seq_list_start(&hctx->dispatch, *pos);
}

static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct blk_mq_hw_ctx *hctx = m->private;

	return seq_list_next(v, &hctx->dispatch, pos);
}

static void hctx_dispatch_stop(struct seq_file *m, void *v)
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	__releases(&hctx->lock)
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{
	struct blk_mq_hw_ctx *hctx = m->private;

	spin_unlock(&hctx->lock);
}

static const struct seq_operations hctx_dispatch_seq_ops = {
	.start	= hctx_dispatch_start,
	.next	= hctx_dispatch_next,
	.stop	= hctx_dispatch_stop,
	.show	= blk_mq_debugfs_rq_show,
};

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static int hctx_ctx_map_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	sbitmap_bitmap_show(&hctx->ctx_map, m);
	return 0;
}

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static void blk_mq_debugfs_tags_show(struct seq_file *m,
				     struct blk_mq_tags *tags)
{
	seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
	seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
	seq_printf(m, "active_queues=%d\n",
		   atomic_read(&tags->active_queues));

	seq_puts(m, "\nbitmap_tags:\n");
	sbitmap_queue_show(&tags->bitmap_tags, m);

	if (tags->nr_reserved_tags) {
		seq_puts(m, "\nbreserved_tags:\n");
		sbitmap_queue_show(&tags->breserved_tags, m);
	}
}

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static int hctx_tags_show(void *data, struct seq_file *m)
399
{
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	struct blk_mq_hw_ctx *hctx = data;
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	struct request_queue *q = hctx->queue;
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	int res;
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	res = mutex_lock_interruptible(&q->sysfs_lock);
	if (res)
		goto out;
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	if (hctx->tags)
		blk_mq_debugfs_tags_show(m, hctx->tags);
	mutex_unlock(&q->sysfs_lock);

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out:
	return res;
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}

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static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	struct request_queue *q = hctx->queue;
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	int res;
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	res = mutex_lock_interruptible(&q->sysfs_lock);
	if (res)
		goto out;
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	if (hctx->tags)
		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
	mutex_unlock(&q->sysfs_lock);
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out:
	return res;
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}

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static int hctx_sched_tags_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	struct request_queue *q = hctx->queue;
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	int res;
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	res = mutex_lock_interruptible(&q->sysfs_lock);
	if (res)
		goto out;
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	if (hctx->sched_tags)
		blk_mq_debugfs_tags_show(m, hctx->sched_tags);
	mutex_unlock(&q->sysfs_lock);

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out:
	return res;
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}

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static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	struct request_queue *q = hctx->queue;
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	int res;
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	res = mutex_lock_interruptible(&q->sysfs_lock);
	if (res)
		goto out;
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	if (hctx->sched_tags)
		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
	mutex_unlock(&q->sysfs_lock);
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out:
	return res;
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}

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static int hctx_io_poll_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	seq_printf(m, "considered=%lu\n", hctx->poll_considered);
	seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
	seq_printf(m, "success=%lu\n", hctx->poll_success);
	return 0;
}

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static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
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				  size_t count, loff_t *ppos)
{
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	struct blk_mq_hw_ctx *hctx = data;
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	hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
	return count;
}

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static int hctx_dispatched_show(void *data, struct seq_file *m)
486
{
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	struct blk_mq_hw_ctx *hctx = data;
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	int i;

	seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);

	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
		unsigned int d = 1U << (i - 1);

		seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
	}

	seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
	return 0;
}

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static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
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				     size_t count, loff_t *ppos)
{
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	struct blk_mq_hw_ctx *hctx = data;
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	int i;

	for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
		hctx->dispatched[i] = 0;
	return count;
}

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static int hctx_queued_show(void *data, struct seq_file *m)
514
{
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	struct blk_mq_hw_ctx *hctx = data;
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	seq_printf(m, "%lu\n", hctx->queued);
	return 0;
}

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static ssize_t hctx_queued_write(void *data, const char __user *buf,
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				 size_t count, loff_t *ppos)
{
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	struct blk_mq_hw_ctx *hctx = data;
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	hctx->queued = 0;
	return count;
}

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static int hctx_run_show(void *data, struct seq_file *m)
531
{
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	struct blk_mq_hw_ctx *hctx = data;
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	seq_printf(m, "%lu\n", hctx->run);
	return 0;
}

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static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
			      loff_t *ppos)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	hctx->run = 0;
	return count;
}

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static int hctx_active_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_hw_ctx *hctx = data;
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	seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
	return 0;
}

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static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
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	__acquires(&ctx->lock)
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{
	struct blk_mq_ctx *ctx = m->private;

	spin_lock(&ctx->lock);
	return seq_list_start(&ctx->rq_list, *pos);
}

static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct blk_mq_ctx *ctx = m->private;

	return seq_list_next(v, &ctx->rq_list, pos);
}

static void ctx_rq_list_stop(struct seq_file *m, void *v)
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	__releases(&ctx->lock)
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{
	struct blk_mq_ctx *ctx = m->private;

	spin_unlock(&ctx->lock);
}

static const struct seq_operations ctx_rq_list_seq_ops = {
	.start	= ctx_rq_list_start,
	.next	= ctx_rq_list_next,
	.stop	= ctx_rq_list_stop,
	.show	= blk_mq_debugfs_rq_show,
};
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static int ctx_dispatched_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_ctx *ctx = data;
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	seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
	return 0;
}

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static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
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				    size_t count, loff_t *ppos)
{
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	struct blk_mq_ctx *ctx = data;
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	ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
	return count;
}

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static int ctx_merged_show(void *data, struct seq_file *m)
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{
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	struct blk_mq_ctx *ctx = data;
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	seq_printf(m, "%lu\n", ctx->rq_merged);
	return 0;
}

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static ssize_t ctx_merged_write(void *data, const char __user *buf,
				size_t count, loff_t *ppos)
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{
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	struct blk_mq_ctx *ctx = data;
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	ctx->rq_merged = 0;
	return count;
}

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static int ctx_completed_show(void *data, struct seq_file *m)
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{
621
	struct blk_mq_ctx *ctx = data;
622 623 624 625 626

	seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
	return 0;
}

627 628
static ssize_t ctx_completed_write(void *data, const char __user *buf,
				   size_t count, loff_t *ppos)
629
{
630 631 632 633
	struct blk_mq_ctx *ctx = data;

	ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
	return count;
634 635
}

636 637 638 639 640 641 642 643 644 645
static int blk_mq_debugfs_show(struct seq_file *m, void *v)
{
	const struct blk_mq_debugfs_attr *attr = m->private;
	void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;

	return attr->show(data, m);
}

static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
				    size_t count, loff_t *ppos)
646 647
{
	struct seq_file *m = file->private_data;
648 649
	const struct blk_mq_debugfs_attr *attr = m->private;
	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
650

651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676
	if (!attr->write)
		return -EPERM;

	return attr->write(data, buf, count, ppos);
}

static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
{
	const struct blk_mq_debugfs_attr *attr = inode->i_private;
	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
	struct seq_file *m;
	int ret;

	if (attr->seq_ops) {
		ret = seq_open(file, attr->seq_ops);
		if (!ret) {
			m = file->private_data;
			m->private = data;
		}
		return ret;
	}

	if (WARN_ON_ONCE(!attr->show))
		return -EPERM;

	return single_open(file, blk_mq_debugfs_show, inode->i_private);
677 678
}

679 680 681 682 683 684 685 686 687 688 689 690
static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
{
	const struct blk_mq_debugfs_attr *attr = inode->i_private;

	if (attr->show)
		return single_release(inode, file);
	else
		return seq_release(inode, file);
}

const struct file_operations blk_mq_debugfs_fops = {
	.open		= blk_mq_debugfs_open,
691
	.read		= seq_read,
692
	.write		= blk_mq_debugfs_write,
693
	.llseek		= seq_lseek,
694
	.release	= blk_mq_debugfs_release,
695 696
};

697
static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
698
	{"poll_stat", 0400, queue_poll_stat_show},
699
	{"requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops},
700
	{"state", 0600, queue_state_show, queue_state_write},
701 702 703
	{},
};

704
static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
705 706 707 708 709 710 711 712 713 714 715 716 717
	{"state", 0400, hctx_state_show},
	{"flags", 0400, hctx_flags_show},
	{"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
	{"ctx_map", 0400, hctx_ctx_map_show},
	{"tags", 0400, hctx_tags_show},
	{"tags_bitmap", 0400, hctx_tags_bitmap_show},
	{"sched_tags", 0400, hctx_sched_tags_show},
	{"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
	{"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
	{"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
	{"queued", 0600, hctx_queued_show, hctx_queued_write},
	{"run", 0600, hctx_run_show, hctx_run_write},
	{"active", 0400, hctx_active_show},
718
	{},
719 720 721
};

static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
722 723 724 725
	{"rq_list", 0400, .seq_ops = &ctx_rq_list_seq_ops},
	{"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
	{"merged", 0600, ctx_merged_show, ctx_merged_write},
	{"completed", 0600, ctx_completed_show, ctx_completed_write},
726
	{},
727 728
};

729 730 731 732 733 734 735 736 737 738 739 740 741
static bool debugfs_create_files(struct dentry *parent, void *data,
				 const struct blk_mq_debugfs_attr *attr)
{
	d_inode(parent)->i_private = data;

	for (; attr->name; attr++) {
		if (!debugfs_create_file(attr->name, attr->mode, parent,
					 (void *)attr, &blk_mq_debugfs_fops))
			return false;
	}
	return true;
}

742
int blk_mq_debugfs_register(struct request_queue *q)
743
{
744 745 746
	struct blk_mq_hw_ctx *hctx;
	int i;

747
	if (!blk_debugfs_root)
748 749
		return -ENOENT;

750 751
	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
					    blk_debugfs_root);
752
	if (!q->debugfs_dir)
753
		return -ENOMEM;
754

755 756
	if (!debugfs_create_files(q->debugfs_dir, q,
				  blk_mq_debugfs_queue_attrs))
757 758
		goto err;

759 760 761 762 763 764 765 766
	/*
	 * blk_mq_init_hctx() attempted to do this already, but q->debugfs_dir
	 * didn't exist yet (because we don't know what to name the directory
	 * until the queue is registered to a gendisk).
	 */
	queue_for_each_hw_ctx(q, hctx, i) {
		if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
			goto err;
767 768 769
		if (q->elevator && !hctx->sched_debugfs_dir &&
		    blk_mq_debugfs_register_sched_hctx(q, hctx))
			goto err;
770 771
	}

772 773 774 775 776 777 778 779 780 781
	return 0;

err:
	blk_mq_debugfs_unregister(q);
	return -ENOMEM;
}

void blk_mq_debugfs_unregister(struct request_queue *q)
{
	debugfs_remove_recursive(q->debugfs_dir);
782
	q->sched_debugfs_dir = NULL;
783 784 785
	q->debugfs_dir = NULL;
}

786 787
static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
				       struct blk_mq_ctx *ctx)
788 789 790 791 792
{
	struct dentry *ctx_dir;
	char name[20];

	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
793
	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
794 795 796
	if (!ctx_dir)
		return -ENOMEM;

797 798
	if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
		return -ENOMEM;
799 800 801 802

	return 0;
}

803 804
int blk_mq_debugfs_register_hctx(struct request_queue *q,
				 struct blk_mq_hw_ctx *hctx)
805 806 807 808 809
{
	struct blk_mq_ctx *ctx;
	char name[20];
	int i;

810 811 812
	if (!q->debugfs_dir)
		return -ENOENT;

813
	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
814 815
	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
	if (!hctx->debugfs_dir)
816 817
		return -ENOMEM;

818 819 820
	if (!debugfs_create_files(hctx->debugfs_dir, hctx,
				  blk_mq_debugfs_hctx_attrs))
		goto err;
821 822

	hctx_for_each_ctx(hctx, ctx, i) {
823 824
		if (blk_mq_debugfs_register_ctx(hctx, ctx))
			goto err;
825 826 827
	}

	return 0;
828 829 830 831 832 833 834 835 836

err:
	blk_mq_debugfs_unregister_hctx(hctx);
	return -ENOMEM;
}

void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
	debugfs_remove_recursive(hctx->debugfs_dir);
837
	hctx->sched_debugfs_dir = NULL;
838
	hctx->debugfs_dir = NULL;
839 840
}

841
int blk_mq_debugfs_register_hctxs(struct request_queue *q)
842 843 844 845 846 847
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i) {
		if (blk_mq_debugfs_register_hctx(q, hctx))
848
			return -ENOMEM;
849 850 851 852 853
	}

	return 0;
}

854
void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
855
{
856 857 858 859 860
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_debugfs_unregister_hctx(hctx);
861
}
862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921

int blk_mq_debugfs_register_sched(struct request_queue *q)
{
	struct elevator_type *e = q->elevator->type;

	if (!q->debugfs_dir)
		return -ENOENT;

	if (!e->queue_debugfs_attrs)
		return 0;

	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
	if (!q->sched_debugfs_dir)
		return -ENOMEM;

	if (!debugfs_create_files(q->sched_debugfs_dir, q,
				  e->queue_debugfs_attrs))
		goto err;

	return 0;

err:
	blk_mq_debugfs_unregister_sched(q);
	return -ENOMEM;
}

void blk_mq_debugfs_unregister_sched(struct request_queue *q)
{
	debugfs_remove_recursive(q->sched_debugfs_dir);
	q->sched_debugfs_dir = NULL;
}

int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
				       struct blk_mq_hw_ctx *hctx)
{
	struct elevator_type *e = q->elevator->type;

	if (!hctx->debugfs_dir)
		return -ENOENT;

	if (!e->hctx_debugfs_attrs)
		return 0;

	hctx->sched_debugfs_dir = debugfs_create_dir("sched",
						     hctx->debugfs_dir);
	if (!hctx->sched_debugfs_dir)
		return -ENOMEM;

	if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
				  e->hctx_debugfs_attrs))
		return -ENOMEM;

	return 0;
}

void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
{
	debugfs_remove_recursive(hctx->sched_debugfs_dir);
	hctx->sched_debugfs_dir = NULL;
}