sysfs.c

// SPDX-License-Identifier: GPL-2.0
/*
 * bcache sysfs interfaces
 *
 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
 * Copyright 2012 Google, Inc.
 */

#include "bcache.h"
#include "sysfs.h"
#include "btree.h"
#include "request.h"
#include "writeback.h"

#include <linux/blkdev.h>
#include <linux/sort.h>
#include <linux/sched/clock.h>

/* Default is -1; we skip past it for struct cached_dev's cache mode */
static const char * const bch_cache_modes[] = {
	"default",
	"writethrough",
	"writeback",
	"writearound",
	"none",
	NULL
};

/* Default is -1; we skip past it for stop_when_cache_set_failed */
static const char * const bch_stop_on_failure_modes[] = {
	"default",
	"auto",
	"always",
	NULL
};

static const char * const cache_replacement_policies[] = {
	"lru",
	"fifo",
	"random",
	NULL
};

static const char * const error_actions[] = {
	"unregister",
	"panic",
	NULL
};

write_attribute(attach);
write_attribute(detach);
write_attribute(unregister);
write_attribute(stop);
write_attribute(clear_stats);
write_attribute(trigger_gc);
write_attribute(prune_cache);
write_attribute(flash_vol_create);

read_attribute(bucket_size);
read_attribute(block_size);
read_attribute(nbuckets);
read_attribute(tree_depth);
read_attribute(root_usage_percent);
read_attribute(priority_stats);
read_attribute(btree_cache_size);
read_attribute(btree_cache_max_chain);
read_attribute(cache_available_percent);
read_attribute(written);
read_attribute(btree_written);
read_attribute(metadata_written);
read_attribute(active_journal_entries);

sysfs_time_stats_attribute(btree_gc,	sec, ms);
sysfs_time_stats_attribute(btree_split, sec, us);
sysfs_time_stats_attribute(btree_sort,	ms,  us);
sysfs_time_stats_attribute(btree_read,	ms,  us);

read_attribute(btree_nodes);
read_attribute(btree_used_percent);
read_attribute(average_key_size);
read_attribute(dirty_data);
read_attribute(bset_tree_stats);

read_attribute(state);
read_attribute(cache_read_races);
read_attribute(reclaim);
read_attribute(flush_write);
read_attribute(retry_flush_write);
read_attribute(writeback_keys_done);
read_attribute(writeback_keys_failed);
read_attribute(io_errors);
read_attribute(congested);
rw_attribute(congested_read_threshold_us);
rw_attribute(congested_write_threshold_us);

rw_attribute(sequential_cutoff);
rw_attribute(data_csum);
rw_attribute(cache_mode);
rw_attribute(stop_when_cache_set_failed);
rw_attribute(writeback_metadata);
rw_attribute(writeback_running);
rw_attribute(writeback_percent);
rw_attribute(writeback_delay);
rw_attribute(writeback_rate);

rw_attribute(writeback_rate_update_seconds);
rw_attribute(writeback_rate_i_term_inverse);
rw_attribute(writeback_rate_p_term_inverse);
rw_attribute(writeback_rate_minimum);
read_attribute(writeback_rate_debug);

read_attribute(stripe_size);
read_attribute(partial_stripes_expensive);

rw_attribute(synchronous);
rw_attribute(journal_delay_ms);
rw_attribute(io_disable);
rw_attribute(discard);
rw_attribute(running);
rw_attribute(label);
rw_attribute(readahead);
rw_attribute(errors);
rw_attribute(io_error_limit);
rw_attribute(io_error_halflife);
rw_attribute(verify);
rw_attribute(bypass_torture_test);
rw_attribute(key_merging_disabled);
rw_attribute(gc_always_rewrite);
rw_attribute(expensive_debug_checks);
rw_attribute(cache_replacement_policy);
rw_attribute(btree_shrinker_disabled);
rw_attribute(copy_gc_enabled);
rw_attribute(size);

static ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
			    size_t selected)
{
	char *out = buf;
	size_t i;

	for (i = 0; list[i]; i++)
		out += snprintf(out, buf + size - out,
				i == selected ? "[%s] " : "%s ", list[i]);

	out[-1] = '\n';
	return out - buf;
}

static ssize_t bch_read_string_list(const char *buf, const char * const list[])
{
	size_t i;
	char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
	if (!d)
		return -ENOMEM;

	s = strim(d);

	for (i = 0; list[i]; i++)
		if (!strcmp(list[i], s))
			break;

	kfree(d);

	if (!list[i])
		return -EINVAL;

	return i;
}

SHOW(__bch_cached_dev)
{
	struct cached_dev *dc = container_of(kobj, struct cached_dev,
					     disk.kobj);
	const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };

#define var(stat)		(dc->stat)

	if (attr == &sysfs_cache_mode)
		return bch_snprint_string_list(buf, PAGE_SIZE,
					       bch_cache_modes + 1,
					       BDEV_CACHE_MODE(&dc->sb));

	if (attr == &sysfs_stop_when_cache_set_failed)
		return bch_snprint_string_list(buf, PAGE_SIZE,
					       bch_stop_on_failure_modes + 1,
					       dc->stop_when_cache_set_failed);


	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
	var_printf(verify,		"%i");
	var_printf(bypass_torture_test,	"%i");
	var_printf(writeback_metadata,	"%i");
	var_printf(writeback_running,	"%i");
	var_print(writeback_delay);
	var_print(writeback_percent);
	sysfs_hprint(writeback_rate,	dc->writeback_rate.rate << 9);
	sysfs_hprint(io_errors,		atomic_read(&dc->io_errors));
	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
	sysfs_printf(io_disable,	"%i", dc->io_disable);
	var_print(writeback_rate_update_seconds);