summaryrefslogtreecommitdiffstats
path: root/fs/erofs/sysfs.c
blob: f3babf1e6608320aa542e563cc12b26cd690e294 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C), 2008-2021, OPPO Mobile Comm Corp., Ltd.
 *             https://www.oppo.com/
 */
#include <linux/sysfs.h>
#include <linux/kobject.h>

#include "internal.h"

enum {
	attr_feature,
	attr_pointer_ui,
	attr_pointer_bool,
};

enum {
	struct_erofs_sb_info,
	struct_erofs_mount_opts,
};

struct erofs_attr {
	struct attribute attr;
	short attr_id;
	int struct_type, offset;
};

#define EROFS_ATTR(_name, _mode, _id)					\
static struct erofs_attr erofs_attr_##_name = {				\
	.attr = {.name = __stringify(_name), .mode = _mode },		\
	.attr_id = attr_##_id,						\
}
#define EROFS_ATTR_FUNC(_name, _mode)	EROFS_ATTR(_name, _mode, _name)
#define EROFS_ATTR_FEATURE(_name)	EROFS_ATTR(_name, 0444, feature)

#define EROFS_ATTR_OFFSET(_name, _mode, _id, _struct)	\
static struct erofs_attr erofs_attr_##_name = {			\
	.attr = {.name = __stringify(_name), .mode = _mode },	\
	.attr_id = attr_##_id,					\
	.struct_type = struct_##_struct,			\
	.offset = offsetof(struct _struct, _name),\
}

#define EROFS_ATTR_RW(_name, _id, _struct)	\
	EROFS_ATTR_OFFSET(_name, 0644, _id, _struct)

#define EROFS_RO_ATTR(_name, _id, _struct)	\
	EROFS_ATTR_OFFSET(_name, 0444, _id, _struct)

#define EROFS_ATTR_RW_UI(_name, _struct)	\
	EROFS_ATTR_RW(_name, pointer_ui, _struct)

#define EROFS_ATTR_RW_BOOL(_name, _struct)	\
	EROFS_ATTR_RW(_name, pointer_bool, _struct)

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

#ifdef CONFIG_EROFS_FS_ZIP
EROFS_ATTR_RW_UI(sync_decompress, erofs_mount_opts);
#endif

static struct attribute *erofs_attrs[] = {
#ifdef CONFIG_EROFS_FS_ZIP
	ATTR_LIST(sync_decompress),
#endif
	NULL,
};
ATTRIBUTE_GROUPS(erofs);

/* Features this copy of erofs supports */
EROFS_ATTR_FEATURE(zero_padding);
EROFS_ATTR_FEATURE(compr_cfgs);
EROFS_ATTR_FEATURE(big_pcluster);
EROFS_ATTR_FEATURE(chunked_file);
EROFS_ATTR_FEATURE(device_table);
EROFS_ATTR_FEATURE(compr_head2);
EROFS_ATTR_FEATURE(sb_chksum);
EROFS_ATTR_FEATURE(ztailpacking);

static struct attribute *erofs_feat_attrs[] = {
	ATTR_LIST(zero_padding),
	ATTR_LIST(compr_cfgs),
	ATTR_LIST(big_pcluster),
	ATTR_LIST(chunked_file),
	ATTR_LIST(device_table),
	ATTR_LIST(compr_head2),
	ATTR_LIST(sb_chksum),
	ATTR_LIST(ztailpacking),
	NULL,
};
ATTRIBUTE_GROUPS(erofs_feat);

static unsigned char *__struct_ptr(struct erofs_sb_info *sbi,
					  int struct_type, int offset)
{
	if (struct_type == struct_erofs_sb_info)
		return (unsigned char *)sbi + offset;
	if (struct_type == struct_erofs_mount_opts)
		return (unsigned char *)&sbi->opt + offset;
	return NULL;
}

static ssize_t erofs_attr_show(struct kobject *kobj,
				struct attribute *attr, char *buf)
{
	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
						s_kobj);
	struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);

	switch (a->attr_id) {
	case attr_feature:
		return sysfs_emit(buf, "supported\n");
	case attr_pointer_ui:
		if (!ptr)
			return 0;
		return sysfs_emit(buf, "%u\n", *(unsigned int *)ptr);
	case attr_pointer_bool:
		if (!ptr)
			return 0;
		return sysfs_emit(buf, "%d\n", *(bool *)ptr);
	}
	return 0;
}

static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
						const char *buf, size_t len)
{
	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
						s_kobj);
	struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
	unsigned long t;
	int ret;

	switch (a->attr_id) {
	case attr_pointer_ui:
		if (!ptr)
			return 0;
		ret = kstrtoul(skip_spaces(buf), 0, &t);
		if (ret)
			return ret;
		if (t != (unsigned int)t)
			return -ERANGE;
#ifdef CONFIG_EROFS_FS_ZIP
		if (!strcmp(a->attr.name, "sync_decompress") &&
		    (t > EROFS_SYNC_DECOMPRESS_FORCE_OFF))
			return -EINVAL;
#endif
		*(unsigned int *)ptr = t;
		return len;
	case attr_pointer_bool:
		if (!ptr)
			return 0;
		ret = kstrtoul(skip_spaces(buf), 0, &t);
		if (ret)
			return ret;
		if (t != 0 && t != 1)
			return -EINVAL;
		*(bool *)ptr = !!t;
		return len;
	}
	return 0;
}

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

static const struct sysfs_ops erofs_attr_ops = {
	.show	= erofs_attr_show,
	.store	= erofs_attr_store,
};

static struct kobj_type erofs_sb_ktype = {
	.default_groups = erofs_groups,
	.sysfs_ops	= &erofs_attr_ops,
	.release	= erofs_sb_release,
};

static struct kobj_type erofs_ktype = {
	.sysfs_ops	= &erofs_attr_ops,
};

static struct kset erofs_root = {
	.kobj	= {.ktype = &erofs_ktype},
};

static struct kobj_type erofs_feat_ktype = {
	.default_groups = erofs_feat_groups,
	.sysfs_ops	= &erofs_attr_ops,
};

static struct kobject erofs_feat = {
	.kset	= &erofs_root,
};

int erofs_register_sysfs(struct super_block *sb)
{
	struct erofs_sb_info *sbi = EROFS_SB(sb);
	int err;

	sbi->s_kobj.kset = &erofs_root;
	init_completion(&sbi->s_kobj_unregister);
	err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL,
				   "%s", sb->s_id);
	if (err)
		goto put_sb_kobj;
	return 0;

put_sb_kobj:
	kobject_put(&sbi->s_kobj);
	wait_for_completion(&sbi->s_kobj_unregister);
	return err;
}

void erofs_unregister_sysfs(struct super_block *sb)
{
	struct erofs_sb_info *sbi = EROFS_SB(sb);

	if (sbi->s_kobj.state_in_sysfs) {
		kobject_del(&sbi->s_kobj);
		kobject_put(&sbi->s_kobj);
		wait_for_completion(&sbi->s_kobj_unregister);
	}
}

int __init erofs_init_sysfs(void)
{
	int ret;

	kobject_set_name(&erofs_root.kobj, "erofs");
	erofs_root.kobj.parent = fs_kobj;
	ret = kset_register(&erofs_root);
	if (ret)
		goto root_err;

	ret = kobject_init_and_add(&erofs_feat, &erofs_feat_ktype,
				   NULL, "features");
	if (ret)
		goto feat_err;
	return ret;

feat_err:
	kobject_put(&erofs_feat);
	kset_unregister(&erofs_root);
root_err:
	return ret;
}

void erofs_exit_sysfs(void)
{
	kobject_put(&erofs_feat);
	kset_unregister(&erofs_root);
}