[mirror_ubuntu-zesty-kernel.git] / fs / ext4 / sysfs.c

/*
 *  linux/fs/ext4/sysfs.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Theodore Ts'o (tytso@mit.edu)
 *
 */

#include <linux/time.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>

#include "ext4.h"
#include "ext4_jbd2.h"

typedef enum {
	attr_noop,
	attr_delayed_allocation_blocks,
	attr_session_write_kbytes,
	attr_lifetime_write_kbytes,
	attr_reserved_clusters,
	attr_inode_readahead,
	attr_trigger_test_error,
	attr_feature,
	attr_pointer_ui,
	attr_pointer_atomic,
} attr_id_t;

typedef enum {
	ptr_explicit,
	ptr_ext4_sb_info_offset,
	ptr_ext4_super_block_offset,
} attr_ptr_t;

static const char *proc_dirname = "fs/ext4";
static struct proc_dir_entry *ext4_proc_root;

struct ext4_attr {
	struct attribute attr;
	short attr_id;
	short attr_ptr;
	union {
		int offset;
		void *explicit_ptr;
	} u;
};

static ssize_t session_write_kbytes_show(struct ext4_attr *a,
					 struct ext4_sb_info *sbi, char *buf)
{
	struct super_block *sb = sbi->s_buddy_cache->i_sb;

	if (!sb->s_bdev->bd_part)
		return snprintf(buf, PAGE_SIZE, "0\n");
	return snprintf(buf, PAGE_SIZE, "%lu\n",
			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
			 sbi->s_sectors_written_start) >> 1);
}

static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
					  struct ext4_sb_info *sbi, char *buf)
{
	struct super_block *sb = sbi->s_buddy_cache->i_sb;

	if (!sb->s_bdev->bd_part)
		return snprintf(buf, PAGE_SIZE, "0\n");
	return snprintf(buf, PAGE_SIZE, "%llu\n",
			(unsigned long long)(sbi->s_kbytes_written +
			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
}

static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
					  struct ext4_sb_info *sbi,
					  const char *buf, size_t count)
{
	unsigned long t;
	int ret;

	ret = kstrtoul(skip_spaces(buf), 0, &t);
	if (ret)
		return ret;

	if (t && (!is_power_of_2(t) || t > 0x40000000))
		return -EINVAL;

	sbi->s_inode_readahead_blks = t;
	return count;
}

static ssize_t reserved_clusters_store(struct ext4_attr *a,
				   struct ext4_sb_info *sbi,
				   const char *buf, size_t count)
{
	unsigned long long val;
	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
				 sbi->s_cluster_bits);
	int ret;

	ret = kstrtoull(skip_spaces(buf), 0, &val);
	if (!ret || val >= clusters)
		return -EINVAL;

	atomic64_set(&sbi->s_resv_clusters, val);
	return count;
}

static ssize_t trigger_test_error(struct ext4_attr *a,
				  struct ext4_sb_info *sbi,
				  const char *buf, size_t count)
{
	int len = count;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (len && buf[len-1] == '\n')
		len--;

	if (len)
		ext4_error(sbi->s_sb, "%.*s", len, buf);
	return count;
}

#define EXT4_ATTR(_name,_mode,_id)					\
static struct ext4_attr ext4_attr_##_name = {				\
	.attr = {.name = __stringify(_name), .mode = _mode },		\
	.attr_id = attr_##_id,						\
}

#define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)

#define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)

#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)	\
static struct ext4_attr ext4_attr_##_name = {			\
	.attr = {.name = __stringify(_name), .mode = _mode },	\
	.attr_id = attr_##_id,					\
	.attr_ptr = ptr_##_struct##_offset,			\
	.u = {							\
		.offset = offsetof(struct _struct, _elname),\
	},							\
}

#define EXT4_RO_ATTR_ES_UI(_name,_elname)				\
	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)

#define EXT4_RW_ATTR_SBI_UI(_name,_elname)	\
	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)

#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
static struct ext4_attr ext4_attr_##_name = {			\
	.attr = {.name = __stringify(_name), .mode = _mode },	\
	.attr_id = attr_##_id,					\
	.attr_ptr = ptr_explicit,				\
	.u = {							\
		.explicit_ptr = _ptr,				\
	},							\
}

#define ATTR_LIST(name) &ext4_attr_##name.attr

EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
EXT4_ATTR_FUNC(session_write_kbytes, 0444);
EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
EXT4_ATTR_FUNC(reserved_clusters, 0644);

EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
		 ext4_sb_info, s_inode_readahead_blks);
EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);

static unsigned int old_bump_val = 128;
EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);

static struct attribute *ext4_attrs[] = {
	ATTR_LIST(delayed_allocation_blocks),
	ATTR_LIST(session_write_kbytes),
	ATTR_LIST(lifetime_write_kbytes),
	ATTR_LIST(reserved_clusters),
	ATTR_LIST(inode_readahead_blks),
	ATTR_LIST(inode_goal),
	ATTR_LIST(mb_stats),
	ATTR_LIST(mb_max_to_scan),
	ATTR_LIST(mb_min_to_scan),
	ATTR_LIST(mb_order2_req),
	ATTR_LIST(mb_stream_req),
	ATTR_LIST(mb_group_prealloc),
	ATTR_LIST(max_writeback_mb_bump),
	ATTR_LIST(extent_max_zeroout_kb),
	ATTR_LIST(trigger_fs_error),
	ATTR_LIST(err_ratelimit_interval_ms),
	ATTR_LIST(err_ratelimit_burst),
	ATTR_LIST(warning_ratelimit_interval_ms),
	ATTR_LIST(warning_ratelimit_burst),
	ATTR_LIST(msg_ratelimit_interval_ms),
	ATTR_LIST(msg_ratelimit_burst),
	ATTR_LIST(errors_count),
	ATTR_LIST(first_error_time),
	ATTR_LIST(last_error_time),
	NULL,
};

/* Features this copy of ext4 supports */
EXT4_ATTR_FEATURE(lazy_itable_init);
EXT4_ATTR_FEATURE(batched_discard);
EXT4_ATTR_FEATURE(meta_bg_resize);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
EXT4_ATTR_FEATURE(encryption);
#endif
EXT4_ATTR_FEATURE(metadata_csum_seed);

static struct attribute *ext4_feat_attrs[] = {
	ATTR_LIST(lazy_itable_init),
	ATTR_LIST(batched_discard),
	ATTR_LIST(meta_bg_resize),
#ifdef CONFIG_EXT4_FS_ENCRYPTION
	ATTR_LIST(encryption),
#endif
	ATTR_LIST(metadata_csum_seed),
	NULL,
};

static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
{
	switch (a->attr_ptr) {
	case ptr_explicit:
		return a->u.explicit_ptr;
	case ptr_ext4_sb_info_offset:
		return (void *) (((char *) sbi) + a->u.offset);
	case ptr_ext4_super_block_offset:
		return (void *) (((char *) sbi->s_es) + a->u.offset);
	}
	return NULL;
}

static ssize_t ext4_attr_show(struct kobject *kobj,
			      struct attribute *attr, char *buf)
{
	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
						s_kobj);
	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
	void *ptr = calc_ptr(a, sbi);

	switch (a->attr_id) {
	case attr_delayed_allocation_blocks:
		return snprintf(buf, PAGE_SIZE, "%llu\n",
				(s64) EXT4_C2B(sbi,
		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
	case attr_session_write_kbytes:
		return session_write_kbytes_show(a, sbi, buf);
	case attr_lifetime_write_kbytes:
		return lifetime_write_kbytes_show(a, sbi, buf);
	case attr_reserved_clusters:
		return snprintf(buf, PAGE_SIZE, "%llu\n",
				(unsigned long long)
				atomic64_read(&sbi->s_resv_clusters));
	case attr_inode_readahead:
	case attr_pointer_ui:
		if (!ptr)
			return 0;
		return snprintf(buf, PAGE_SIZE, "%u\n",
				*((unsigned int *) ptr));
	case attr_pointer_atomic:
		if (!ptr)
			return 0;
		return snprintf(buf, PAGE_SIZE, "%d\n",
				atomic_read((atomic_t *) ptr));
	case attr_feature:
		return snprintf(buf, PAGE_SIZE, "supported\n");
	}

	return 0;
}

static ssize_t ext4_attr_store(struct kobject *kobj,
			       struct attribute *attr,
			       const char *buf, size_t len)
{
	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
						s_kobj);
	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
	void *ptr = calc_ptr(a, sbi);
	unsigned long t;
	int ret;

	switch (a->attr_id) {
	case attr_reserved_clusters:
		return reserved_clusters_store(a, sbi, buf, len);
	case attr_pointer_ui:
		if (!ptr)
			return 0;
		ret = kstrtoul(skip_spaces(buf), 0, &t);
		if (ret)
			return ret;
		*((unsigned int *) ptr) = t;
		return len;
	case attr_inode_readahead:
		return inode_readahead_blks_store(a, sbi, buf, len);
	case attr_trigger_test_error:
		return trigger_test_error(a, sbi, buf, len);
	}
	return 0;
}

static void ext4_sb_release(struct kobject *kobj)
{
	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
						s_kobj);
	complete(&sbi->s_kobj_unregister);
}

static const struct sysfs_ops ext4_attr_ops = {
	.show	= ext4_attr_show,
	.store	= ext4_attr_store,
};

static struct kobj_type ext4_sb_ktype = {
	.default_attrs	= ext4_attrs,
	.sysfs_ops	= &ext4_attr_ops,
	.release	= ext4_sb_release,
};

static struct kobj_type ext4_ktype = {
	.sysfs_ops	= &ext4_attr_ops,
};

static struct kset ext4_kset = {
	.kobj   = {.ktype = &ext4_ktype},
};

static struct kobj_type ext4_feat_ktype = {
	.default_attrs	= ext4_feat_attrs,
	.sysfs_ops	= &ext4_attr_ops,
};

static struct kobject ext4_feat = {
	.kset	= &ext4_kset,
};

#define PROC_FILE_SHOW_DEFN(name) \
static int name##_open(struct inode *inode, struct file *file) \
{ \
	return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
} \
\
static const struct file_operations ext4_seq_##name##_fops = { \
	.open		= name##_open, \
	.read		= seq_read, \
	.llseek		= seq_lseek, \
	.release	= single_release, \
}

#define PROC_FILE_LIST(name) \
	{ __stringify(name), &ext4_seq_##name##_fops }

PROC_FILE_SHOW_DEFN(es_shrinker_info);
PROC_FILE_SHOW_DEFN(options);

static struct ext4_proc_files {
	const char *name;
	const struct file_operations *fops;
} proc_files[] = {
	PROC_FILE_LIST(options),
	PROC_FILE_LIST(es_shrinker_info),
	PROC_FILE_LIST(mb_groups),
	{ NULL, NULL },
};

int ext4_register_sysfs(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_proc_files *p;
	int err;

	sbi->s_kobj.kset = &ext4_kset;
	init_completion(&sbi->s_kobj_unregister);
	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
				   "%s", sb->s_id);
	if (err)
		return err;

	if (ext4_proc_root)
		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);

	if (sbi->s_proc) {
		for (p = proc_files; p->name; p++)
			proc_create_data(p->name, S_IRUGO, sbi->s_proc,
					 p->fops, sb);
	}
	return 0;
}

void ext4_unregister_sysfs(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_proc_files *p;

	if (sbi->s_proc) {
		for (p = proc_files; p->name; p++)
			remove_proc_entry(p->name, sbi->s_proc);
		remove_proc_entry(sb->s_id, ext4_proc_root);
	}
	kobject_del(&sbi->s_kobj);
}

int __init ext4_init_sysfs(void)
{
	int ret;

	kobject_set_name(&ext4_kset.kobj, "ext4");
	ext4_kset.kobj.parent = fs_kobj;
	ret = kset_register(&ext4_kset);
	if (ret)
		return ret;

	ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
				   NULL, "features");
	if (ret)
		kset_unregister(&ext4_kset);
	else
		ext4_proc_root = proc_mkdir(proc_dirname, NULL);
	return ret;
}

void ext4_exit_sysfs(void)
{
	kobject_put(&ext4_feat);
	kset_unregister(&ext4_kset);
	remove_proc_entry(proc_dirname, NULL);
	ext4_proc_root = NULL;
}
Commit	Line	Data
	1	/*
	2	* linux/fs/ext4/sysfs.c
	3	*
	4	* Copyright (C) 1992, 1993, 1994, 1995
	5	* Remy Card (card@masi.ibp.fr)
	6	* Theodore Ts'o (tytso@mit.edu)
	7	*
	8	*/
	9
	10	#include <linux/time.h>
	11	#include <linux/fs.h>
	12	#include <linux/seq_file.h>
	13	#include <linux/proc_fs.h>
	14
	15	#include "ext4.h"
	16	#include "ext4_jbd2.h"
	17
	18	typedef enum {
	19	attr_noop,
	20	attr_delayed_allocation_blocks,
	21	attr_session_write_kbytes,
	22	attr_lifetime_write_kbytes,
	23	attr_reserved_clusters,
	24	attr_inode_readahead,
	25	attr_trigger_test_error,
	26	attr_feature,
	27	attr_pointer_ui,
	28	attr_pointer_atomic,
	29	} attr_id_t;
	30
	31	typedef enum {
	32	ptr_explicit,
	33	ptr_ext4_sb_info_offset,
	34	ptr_ext4_super_block_offset,
	35	} attr_ptr_t;
	36
	37	static const char *proc_dirname = "fs/ext4";
	38	static struct proc_dir_entry *ext4_proc_root;
	39
	40	struct ext4_attr {
	41	struct attribute attr;
	42	short attr_id;
	43	short attr_ptr;
	44	union {
	45	int offset;
	46	void *explicit_ptr;
	47	} u;
	48	};
	49
	50	static ssize_t session_write_kbytes_show(struct ext4_attr *a,
	51	struct ext4_sb_info sbi, char buf)
	52	{
	53	struct super_block *sb = sbi->s_buddy_cache->i_sb;
	54
	55	if (!sb->s_bdev->bd_part)
	56	return snprintf(buf, PAGE_SIZE, "0\n");
	57	return snprintf(buf, PAGE_SIZE, "%lu\n",
	58	(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
	59	sbi->s_sectors_written_start) >> 1);
	60	}
	61
	62	static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
	63	struct ext4_sb_info sbi, char buf)
	64	{
	65	struct super_block *sb = sbi->s_buddy_cache->i_sb;
	66
	67	if (!sb->s_bdev->bd_part)
	68	return snprintf(buf, PAGE_SIZE, "0\n");
	69	return snprintf(buf, PAGE_SIZE, "%llu\n",
	70	(unsigned long long)(sbi->s_kbytes_written +
	71	((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
	72	EXT4_SB(sb)->s_sectors_written_start) >> 1)));
	73	}
	74
	75	static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
	76	struct ext4_sb_info *sbi,
	77	const char *buf, size_t count)
	78	{
	79	unsigned long t;
	80	int ret;
	81
	82	ret = kstrtoul(skip_spaces(buf), 0, &t);
	83	if (ret)
	84	return ret;
	85
	86	if (t && (!is_power_of_2(t) \|\| t > 0x40000000))
	87	return -EINVAL;
	88
	89	sbi->s_inode_readahead_blks = t;
	90	return count;
	91	}
	92
	93	static ssize_t reserved_clusters_store(struct ext4_attr *a,
	94	struct ext4_sb_info *sbi,
	95	const char *buf, size_t count)
	96	{
	97	unsigned long long val;
	98	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
	99	sbi->s_cluster_bits);
	100	int ret;
	101
	102	ret = kstrtoull(skip_spaces(buf), 0, &val);
	103	if (!ret \|\| val >= clusters)
	104	return -EINVAL;
	105
	106	atomic64_set(&sbi->s_resv_clusters, val);
	107	return count;
	108	}
	109
	110	static ssize_t trigger_test_error(struct ext4_attr *a,
	111	struct ext4_sb_info *sbi,
	112	const char *buf, size_t count)
	113	{
	114	int len = count;
	115
	116	if (!capable(CAP_SYS_ADMIN))
	117	return -EPERM;
	118
	119	if (len && buf[len-1] == '\n')
	120	len--;
	121
	122	if (len)
	123	ext4_error(sbi->s_sb, "%.*s", len, buf);
	124	return count;
	125	}
	126
	127	#define EXT4_ATTR(_name,_mode,_id) \
	128	static struct ext4_attr ext4_attr_##_name = { \
	129	.attr = {.name = __stringify(_name), .mode = _mode }, \
	130	.attr_id = attr_##_id, \
	131	}
	132
	133	#define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name)
	134
	135	#define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature)
	136
	137	#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \
	138	static struct ext4_attr ext4_attr_##_name = { \
	139	.attr = {.name = __stringify(_name), .mode = _mode }, \
	140	.attr_id = attr_##_id, \
	141	.attr_ptr = ptr_##_struct##_offset, \
	142	.u = { \
	143	.offset = offsetof(struct _struct, _elname),\
	144	}, \
	145	}
	146
	147	#define EXT4_RO_ATTR_ES_UI(_name,_elname) \
	148	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
	149
	150	#define EXT4_RW_ATTR_SBI_UI(_name,_elname) \
	151	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
	152
	153	#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
	154	static struct ext4_attr ext4_attr_##_name = { \
	155	.attr = {.name = __stringify(_name), .mode = _mode }, \
	156	.attr_id = attr_##_id, \
	157	.attr_ptr = ptr_explicit, \
	158	.u = { \
	159	.explicit_ptr = _ptr, \
	160	}, \
	161	}
	162
	163	#define ATTR_LIST(name) &ext4_attr_##name.attr
	164
	165	EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
	166	EXT4_ATTR_FUNC(session_write_kbytes, 0444);
	167	EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
	168	EXT4_ATTR_FUNC(reserved_clusters, 0644);
	169
	170	EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
	171	ext4_sb_info, s_inode_readahead_blks);
	172	EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
	173	EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
	174	EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
	175	EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
	176	EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
	177	EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
	178	EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
	179	EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
	180	EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
	181	EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
	182	EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
	183	EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
	184	EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
	185	EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
	186	EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
	187	EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
	188	EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
	189	EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
	190
	191	static unsigned int old_bump_val = 128;
	192	EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
	193
	194	static struct attribute *ext4_attrs[] = {
	195	ATTR_LIST(delayed_allocation_blocks),
	196	ATTR_LIST(session_write_kbytes),
	197	ATTR_LIST(lifetime_write_kbytes),
	198	ATTR_LIST(reserved_clusters),
	199	ATTR_LIST(inode_readahead_blks),
	200	ATTR_LIST(inode_goal),
	201	ATTR_LIST(mb_stats),
	202	ATTR_LIST(mb_max_to_scan),
	203	ATTR_LIST(mb_min_to_scan),
	204	ATTR_LIST(mb_order2_req),
	205	ATTR_LIST(mb_stream_req),
	206	ATTR_LIST(mb_group_prealloc),
	207	ATTR_LIST(max_writeback_mb_bump),
	208	ATTR_LIST(extent_max_zeroout_kb),
	209	ATTR_LIST(trigger_fs_error),
	210	ATTR_LIST(err_ratelimit_interval_ms),
	211	ATTR_LIST(err_ratelimit_burst),
	212	ATTR_LIST(warning_ratelimit_interval_ms),
	213	ATTR_LIST(warning_ratelimit_burst),
	214	ATTR_LIST(msg_ratelimit_interval_ms),
	215	ATTR_LIST(msg_ratelimit_burst),
	216	ATTR_LIST(errors_count),
	217	ATTR_LIST(first_error_time),
	218	ATTR_LIST(last_error_time),
	219	NULL,
	220	};
	221
	222	/* Features this copy of ext4 supports */
	223	EXT4_ATTR_FEATURE(lazy_itable_init);
	224	EXT4_ATTR_FEATURE(batched_discard);
	225	EXT4_ATTR_FEATURE(meta_bg_resize);
	226	#ifdef CONFIG_EXT4_FS_ENCRYPTION
	227	EXT4_ATTR_FEATURE(encryption);
	228	#endif
	229	EXT4_ATTR_FEATURE(metadata_csum_seed);
	230
	231	static struct attribute *ext4_feat_attrs[] = {
	232	ATTR_LIST(lazy_itable_init),
	233	ATTR_LIST(batched_discard),
	234	ATTR_LIST(meta_bg_resize),
	235	#ifdef CONFIG_EXT4_FS_ENCRYPTION
	236	ATTR_LIST(encryption),
	237	#endif
	238	ATTR_LIST(metadata_csum_seed),
	239	NULL,
	240	};
	241
	242	static void calc_ptr(struct ext4_attr a, struct ext4_sb_info *sbi)
	243	{
	244	switch (a->attr_ptr) {
	245	case ptr_explicit:
	246	return a->u.explicit_ptr;
	247	case ptr_ext4_sb_info_offset:
	248	return (void ) (((char ) sbi) + a->u.offset);
	249	case ptr_ext4_super_block_offset:
	250	return (void ) (((char ) sbi->s_es) + a->u.offset);
	251	}
	252	return NULL;
	253	}
	254
	255	static ssize_t ext4_attr_show(struct kobject *kobj,
	256	struct attribute attr, char buf)
	257	{
	258	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
	259	s_kobj);
	260	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
	261	void *ptr = calc_ptr(a, sbi);
	262
	263	switch (a->attr_id) {
	264	case attr_delayed_allocation_blocks:
	265	return snprintf(buf, PAGE_SIZE, "%llu\n",
	266	(s64) EXT4_C2B(sbi,
	267	percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
	268	case attr_session_write_kbytes:
	269	return session_write_kbytes_show(a, sbi, buf);
	270	case attr_lifetime_write_kbytes:
	271	return lifetime_write_kbytes_show(a, sbi, buf);
	272	case attr_reserved_clusters:
	273	return snprintf(buf, PAGE_SIZE, "%llu\n",
	274	(unsigned long long)
	275	atomic64_read(&sbi->s_resv_clusters));
	276	case attr_inode_readahead:
	277	case attr_pointer_ui:
	278	if (!ptr)
	279	return 0;
	280	return snprintf(buf, PAGE_SIZE, "%u\n",
	281	((unsigned int ) ptr));
	282	case attr_pointer_atomic:
	283	if (!ptr)
	284	return 0;
	285	return snprintf(buf, PAGE_SIZE, "%d\n",
	286	atomic_read((atomic_t *) ptr));
	287	case attr_feature:
	288	return snprintf(buf, PAGE_SIZE, "supported\n");
	289	}
	290
	291	return 0;
	292	}
	293
	294	static ssize_t ext4_attr_store(struct kobject *kobj,
	295	struct attribute *attr,
	296	const char *buf, size_t len)
	297	{
	298	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
	299	s_kobj);
	300	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
	301	void *ptr = calc_ptr(a, sbi);
	302	unsigned long t;
	303	int ret;
	304
	305	switch (a->attr_id) {
	306	case attr_reserved_clusters:
	307	return reserved_clusters_store(a, sbi, buf, len);
	308	case attr_pointer_ui:
	309	if (!ptr)
	310	return 0;
	311	ret = kstrtoul(skip_spaces(buf), 0, &t);
	312	if (ret)
	313	return ret;
	314	((unsigned int ) ptr) = t;
	315	return len;
	316	case attr_inode_readahead:
	317	return inode_readahead_blks_store(a, sbi, buf, len);
	318	case attr_trigger_test_error:
	319	return trigger_test_error(a, sbi, buf, len);
	320	}
	321	return 0;
	322	}
	323
	324	static void ext4_sb_release(struct kobject *kobj)
	325	{
	326	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
	327	s_kobj);
	328	complete(&sbi->s_kobj_unregister);
	329	}
	330
	331	static const struct sysfs_ops ext4_attr_ops = {
	332	.show = ext4_attr_show,
	333	.store = ext4_attr_store,
	334	};
	335
	336	static struct kobj_type ext4_sb_ktype = {
	337	.default_attrs = ext4_attrs,
	338	.sysfs_ops = &ext4_attr_ops,
	339	.release = ext4_sb_release,
	340	};
	341
	342	static struct kobj_type ext4_ktype = {
	343	.sysfs_ops = &ext4_attr_ops,
	344	};
	345
	346	static struct kset ext4_kset = {
	347	.kobj = {.ktype = &ext4_ktype},
	348	};
	349
	350	static struct kobj_type ext4_feat_ktype = {
	351	.default_attrs = ext4_feat_attrs,
	352	.sysfs_ops = &ext4_attr_ops,
	353	};
	354
	355	static struct kobject ext4_feat = {
	356	.kset = &ext4_kset,
	357	};
	358
	359	#define PROC_FILE_SHOW_DEFN(name) \
	360	static int name##_open(struct inode inode, struct file file) \
	361	{ \
	362	return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
	363	} \
	364	\
	365	static const struct file_operations ext4_seq_##name##_fops = { \
	366	.open = name##_open, \
	367	.read = seq_read, \
	368	.llseek = seq_lseek, \
	369	.release = single_release, \
	370	}
	371
	372	#define PROC_FILE_LIST(name) \
	373	{ __stringify(name), &ext4_seq_##name##_fops }
	374
	375	PROC_FILE_SHOW_DEFN(es_shrinker_info);
	376	PROC_FILE_SHOW_DEFN(options);
	377
	378	static struct ext4_proc_files {
	379	const char *name;
	380	const struct file_operations *fops;
	381	} proc_files[] = {
	382	PROC_FILE_LIST(options),
	383	PROC_FILE_LIST(es_shrinker_info),
	384	PROC_FILE_LIST(mb_groups),
	385	{ NULL, NULL },
	386	};
	387
	388	int ext4_register_sysfs(struct super_block *sb)
	389	{
	390	struct ext4_sb_info *sbi = EXT4_SB(sb);
	391	struct ext4_proc_files *p;
	392	int err;
	393
	394	sbi->s_kobj.kset = &ext4_kset;
	395	init_completion(&sbi->s_kobj_unregister);
	396	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
	397	"%s", sb->s_id);
	398	if (err)
	399	return err;
	400
	401	if (ext4_proc_root)
	402	sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
	403
	404	if (sbi->s_proc) {
	405	for (p = proc_files; p->name; p++)
	406	proc_create_data(p->name, S_IRUGO, sbi->s_proc,
	407	p->fops, sb);
	408	}
	409	return 0;
	410	}
	411
	412	void ext4_unregister_sysfs(struct super_block *sb)
	413	{
	414	struct ext4_sb_info *sbi = EXT4_SB(sb);
	415	struct ext4_proc_files *p;
	416
	417	if (sbi->s_proc) {
	418	for (p = proc_files; p->name; p++)
	419	remove_proc_entry(p->name, sbi->s_proc);
	420	remove_proc_entry(sb->s_id, ext4_proc_root);
	421	}
	422	kobject_del(&sbi->s_kobj);
	423	}
	424
	425	int __init ext4_init_sysfs(void)
	426	{
	427	int ret;
	428
	429	kobject_set_name(&ext4_kset.kobj, "ext4");
	430	ext4_kset.kobj.parent = fs_kobj;
	431	ret = kset_register(&ext4_kset);
	432	if (ret)
	433	return ret;
	434
	435	ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
	436	NULL, "features");
	437	if (ret)
	438	kset_unregister(&ext4_kset);
	439	else
	440	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
	441	return ret;
	442	}
	443
	444	void ext4_exit_sysfs(void)
	445	{
	446	kobject_put(&ext4_feat);
	447	kset_unregister(&ext4_kset);
	448	remove_proc_entry(proc_dirname, NULL);
	449	ext4_proc_root = NULL;
	450	}
	451