Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C), 2008-2021, OPPO Mobile Comm Corp., Ltd.
4 * https://www.oppo.com/
5 */
6#include <linux/sysfs.h>
7#include <linux/kobject.h>
8
9#include "internal.h"
10
11enum {
12 attr_feature,
13 attr_drop_caches,
14 attr_pointer_ui,
15 attr_pointer_bool,
16};
17
18enum {
19 struct_erofs_sb_info,
20 struct_erofs_mount_opts,
21};
22
23struct erofs_attr {
24 struct attribute attr;
25 short attr_id;
26 int struct_type, offset;
27};
28
29#define EROFS_ATTR(_name, _mode, _id) \
30static struct erofs_attr erofs_attr_##_name = { \
31 .attr = {.name = __stringify(_name), .mode = _mode }, \
32 .attr_id = attr_##_id, \
33}
34#define EROFS_ATTR_FUNC(_name, _mode) EROFS_ATTR(_name, _mode, _name)
35#define EROFS_ATTR_FEATURE(_name) EROFS_ATTR(_name, 0444, feature)
36
37#define EROFS_ATTR_OFFSET(_name, _mode, _id, _struct) \
38static struct erofs_attr erofs_attr_##_name = { \
39 .attr = {.name = __stringify(_name), .mode = _mode }, \
40 .attr_id = attr_##_id, \
41 .struct_type = struct_##_struct, \
42 .offset = offsetof(struct _struct, _name),\
43}
44
45#define EROFS_ATTR_RW(_name, _id, _struct) \
46 EROFS_ATTR_OFFSET(_name, 0644, _id, _struct)
47
48#define EROFS_RO_ATTR(_name, _id, _struct) \
49 EROFS_ATTR_OFFSET(_name, 0444, _id, _struct)
50
51#define EROFS_ATTR_RW_UI(_name, _struct) \
52 EROFS_ATTR_RW(_name, pointer_ui, _struct)
53
54#define EROFS_ATTR_RW_BOOL(_name, _struct) \
55 EROFS_ATTR_RW(_name, pointer_bool, _struct)
56
57#define ATTR_LIST(name) (&erofs_attr_##name.attr)
58
59#ifdef CONFIG_EROFS_FS_ZIP
60EROFS_ATTR_RW_UI(sync_decompress, erofs_mount_opts);
61EROFS_ATTR_FUNC(drop_caches, 0200);
62#endif
63
64static struct attribute *erofs_attrs[] = {
65#ifdef CONFIG_EROFS_FS_ZIP
66 ATTR_LIST(sync_decompress),
67 ATTR_LIST(drop_caches),
68#endif
69 NULL,
70};
71ATTRIBUTE_GROUPS(erofs);
72
73/* Features this copy of erofs supports */
74EROFS_ATTR_FEATURE(zero_padding);
75EROFS_ATTR_FEATURE(compr_cfgs);
76EROFS_ATTR_FEATURE(big_pcluster);
77EROFS_ATTR_FEATURE(chunked_file);
78EROFS_ATTR_FEATURE(device_table);
79EROFS_ATTR_FEATURE(compr_head2);
80EROFS_ATTR_FEATURE(sb_chksum);
81EROFS_ATTR_FEATURE(ztailpacking);
82EROFS_ATTR_FEATURE(fragments);
83EROFS_ATTR_FEATURE(dedupe);
84
85static struct attribute *erofs_feat_attrs[] = {
86 ATTR_LIST(zero_padding),
87 ATTR_LIST(compr_cfgs),
88 ATTR_LIST(big_pcluster),
89 ATTR_LIST(chunked_file),
90 ATTR_LIST(device_table),
91 ATTR_LIST(compr_head2),
92 ATTR_LIST(sb_chksum),
93 ATTR_LIST(ztailpacking),
94 ATTR_LIST(fragments),
95 ATTR_LIST(dedupe),
96 NULL,
97};
98ATTRIBUTE_GROUPS(erofs_feat);
99
100static unsigned char *__struct_ptr(struct erofs_sb_info *sbi,
101 int struct_type, int offset)
102{
103 if (struct_type == struct_erofs_sb_info)
104 return (unsigned char *)sbi + offset;
105 if (struct_type == struct_erofs_mount_opts)
106 return (unsigned char *)&sbi->opt + offset;
107 return NULL;
108}
109
110static ssize_t erofs_attr_show(struct kobject *kobj,
111 struct attribute *attr, char *buf)
112{
113 struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
114 s_kobj);
115 struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
116 unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
117
118 switch (a->attr_id) {
119 case attr_feature:
120 return sysfs_emit(buf, "supported\n");
121 case attr_pointer_ui:
122 if (!ptr)
123 return 0;
124 return sysfs_emit(buf, "%u\n", *(unsigned int *)ptr);
125 case attr_pointer_bool:
126 if (!ptr)
127 return 0;
128 return sysfs_emit(buf, "%d\n", *(bool *)ptr);
129 }
130 return 0;
131}
132
133static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
134 const char *buf, size_t len)
135{
136 struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
137 s_kobj);
138 struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
139 unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
140 unsigned long t;
141 int ret;
142
143 switch (a->attr_id) {
144 case attr_pointer_ui:
145 if (!ptr)
146 return 0;
147 ret = kstrtoul(skip_spaces(buf), 0, &t);
148 if (ret)
149 return ret;
150 if (t != (unsigned int)t)
151 return -ERANGE;
152#ifdef CONFIG_EROFS_FS_ZIP
153 if (!strcmp(a->attr.name, "sync_decompress") &&
154 (t > EROFS_SYNC_DECOMPRESS_FORCE_OFF))
155 return -EINVAL;
156#endif
157 *(unsigned int *)ptr = t;
158 return len;
159 case attr_pointer_bool:
160 if (!ptr)
161 return 0;
162 ret = kstrtoul(skip_spaces(buf), 0, &t);
163 if (ret)
164 return ret;
165 if (t != 0 && t != 1)
166 return -EINVAL;
167 *(bool *)ptr = !!t;
168 return len;
169#ifdef CONFIG_EROFS_FS_ZIP
170 case attr_drop_caches:
171 ret = kstrtoul(skip_spaces(buf), 0, &t);
172 if (ret)
173 return ret;
174 if (t < 1 || t > 3)
175 return -EINVAL;
176
177 if (t & 2)
178 z_erofs_shrink_scan(sbi, ~0UL);
179 if (t & 1)
180 invalidate_mapping_pages(MNGD_MAPPING(sbi), 0, -1);
181 return len;
182#endif
183 }
184 return 0;
185}
186
187static void erofs_sb_release(struct kobject *kobj)
188{
189 struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
190 s_kobj);
191 complete(&sbi->s_kobj_unregister);
192}
193
194static const struct sysfs_ops erofs_attr_ops = {
195 .show = erofs_attr_show,
196 .store = erofs_attr_store,
197};
198
199static const struct kobj_type erofs_sb_ktype = {
200 .default_groups = erofs_groups,
201 .sysfs_ops = &erofs_attr_ops,
202 .release = erofs_sb_release,
203};
204
205static const struct kobj_type erofs_ktype = {
206 .sysfs_ops = &erofs_attr_ops,
207};
208
209static struct kset erofs_root = {
210 .kobj = {.ktype = &erofs_ktype},
211};
212
213static const struct kobj_type erofs_feat_ktype = {
214 .default_groups = erofs_feat_groups,
215 .sysfs_ops = &erofs_attr_ops,
216};
217
218static struct kobject erofs_feat = {
219 .kset = &erofs_root,
220};
221
222int erofs_register_sysfs(struct super_block *sb)
223{
224 struct erofs_sb_info *sbi = EROFS_SB(sb);
225 int err;
226
227 sbi->s_kobj.kset = &erofs_root;
228 init_completion(&sbi->s_kobj_unregister);
229 err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s",
230 sb->s_sysfs_name);
231 if (err) {
232 kobject_put(&sbi->s_kobj);
233 wait_for_completion(&sbi->s_kobj_unregister);
234 }
235 return err;
236}
237
238void erofs_unregister_sysfs(struct super_block *sb)
239{
240 struct erofs_sb_info *sbi = EROFS_SB(sb);
241
242 if (sbi->s_kobj.state_in_sysfs) {
243 kobject_del(&sbi->s_kobj);
244 kobject_put(&sbi->s_kobj);
245 wait_for_completion(&sbi->s_kobj_unregister);
246 }
247}
248
249int __init erofs_init_sysfs(void)
250{
251 int ret;
252
253 kobject_set_name(&erofs_root.kobj, "erofs");
254 erofs_root.kobj.parent = fs_kobj;
255 ret = kset_register(&erofs_root);
256 if (ret)
257 goto root_err;
258
259 ret = kobject_init_and_add(&erofs_feat, &erofs_feat_ktype,
260 NULL, "features");
261 if (ret)
262 goto feat_err;
263 return ret;
264
265feat_err:
266 kobject_put(&erofs_feat);
267 kset_unregister(&erofs_root);
268root_err:
269 return ret;
270}
271
272void erofs_exit_sysfs(void)
273{
274 kobject_put(&erofs_feat);
275 kset_unregister(&erofs_root);
276}