xref: /linux/fs/erofs/sysfs.c (revision c7c707cbaa5ed277836364da4033e141ff985678)
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 #include "compress.h"
11 
12 enum {
13 	attr_feature,
14 	attr_drop_caches,
15 	attr_pointer_ui,
16 	attr_pointer_bool,
17 	attr_accel,
18 };
19 
20 enum {
21 	struct_erofs_sb_info,
22 	struct_erofs_mount_opts,
23 };
24 
25 struct erofs_attr {
26 	struct attribute attr;
27 	short attr_id;
28 	int struct_type, offset;
29 };
30 
31 #define EROFS_ATTR(_name, _mode, _id)					\
32 static struct erofs_attr erofs_attr_##_name = {				\
33 	.attr = {.name = __stringify(_name), .mode = _mode },		\
34 	.attr_id = attr_##_id,						\
35 }
36 #define EROFS_ATTR_FUNC(_name, _mode)	EROFS_ATTR(_name, _mode, _name)
37 #define EROFS_ATTR_FEATURE(_name)	EROFS_ATTR(_name, 0444, feature)
38 
39 #define EROFS_ATTR_OFFSET(_name, _mode, _id, _struct)	\
40 static struct erofs_attr erofs_attr_##_name = {			\
41 	.attr = {.name = __stringify(_name), .mode = _mode },	\
42 	.attr_id = attr_##_id,					\
43 	.struct_type = struct_##_struct,			\
44 	.offset = offsetof(struct _struct, _name),\
45 }
46 
47 #define EROFS_ATTR_RW(_name, _id, _struct)	\
48 	EROFS_ATTR_OFFSET(_name, 0644, _id, _struct)
49 
50 #define EROFS_RO_ATTR(_name, _id, _struct)	\
51 	EROFS_ATTR_OFFSET(_name, 0444, _id, _struct)
52 
53 #define EROFS_ATTR_RW_UI(_name, _struct)	\
54 	EROFS_ATTR_RW(_name, pointer_ui, _struct)
55 
56 #define EROFS_ATTR_RW_BOOL(_name, _struct)	\
57 	EROFS_ATTR_RW(_name, pointer_bool, _struct)
58 
59 #define ATTR_LIST(name) (&erofs_attr_##name.attr)
60 
61 #ifdef CONFIG_EROFS_FS_ZIP
62 EROFS_ATTR_RW_UI(sync_decompress, erofs_sb_info);
63 EROFS_ATTR_FUNC(drop_caches, 0200);
64 #endif
65 #ifdef CONFIG_EROFS_FS_ZIP_ACCEL
66 EROFS_ATTR_FUNC(accel, 0644);
67 #endif
68 EROFS_ATTR_RW_UI(dir_ra_bytes, erofs_sb_info);
69 
70 static struct attribute *erofs_sb_attrs[] = {
71 #ifdef CONFIG_EROFS_FS_ZIP
72 	ATTR_LIST(sync_decompress),
73 	ATTR_LIST(drop_caches),
74 #endif
75 	ATTR_LIST(dir_ra_bytes),
76 	NULL,
77 };
78 ATTRIBUTE_GROUPS(erofs_sb);
79 
80 static struct attribute *erofs_attrs[] = {
81 #ifdef CONFIG_EROFS_FS_ZIP_ACCEL
82 	ATTR_LIST(accel),
83 #endif
84 	NULL,
85 };
86 ATTRIBUTE_GROUPS(erofs);
87 
88 /* Features this copy of erofs supports */
89 EROFS_ATTR_FEATURE(compr_cfgs);
90 EROFS_ATTR_FEATURE(big_pcluster);
91 EROFS_ATTR_FEATURE(chunked_file);
92 EROFS_ATTR_FEATURE(device_table);
93 EROFS_ATTR_FEATURE(compr_head2);
94 EROFS_ATTR_FEATURE(sb_chksum);
95 EROFS_ATTR_FEATURE(ztailpacking);
96 EROFS_ATTR_FEATURE(fragments);
97 EROFS_ATTR_FEATURE(dedupe);
98 EROFS_ATTR_FEATURE(48bit);
99 EROFS_ATTR_FEATURE(metabox);
100 
101 static struct attribute *erofs_feat_attrs[] = {
102 	ATTR_LIST(compr_cfgs),
103 	ATTR_LIST(big_pcluster),
104 	ATTR_LIST(chunked_file),
105 	ATTR_LIST(device_table),
106 	ATTR_LIST(compr_head2),
107 	ATTR_LIST(sb_chksum),
108 	ATTR_LIST(ztailpacking),
109 	ATTR_LIST(fragments),
110 	ATTR_LIST(dedupe),
111 	ATTR_LIST(48bit),
112 	ATTR_LIST(metabox),
113 	NULL,
114 };
115 ATTRIBUTE_GROUPS(erofs_feat);
116 
117 static unsigned char *__struct_ptr(struct erofs_sb_info *sbi,
118 					  int struct_type, int offset)
119 {
120 	if (struct_type == struct_erofs_sb_info)
121 		return (unsigned char *)sbi + offset;
122 	if (struct_type == struct_erofs_mount_opts)
123 		return (unsigned char *)&sbi->opt + offset;
124 	return NULL;
125 }
126 
127 static ssize_t erofs_attr_show(struct kobject *kobj,
128 				struct attribute *attr, char *buf)
129 {
130 	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
131 						s_kobj);
132 	struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
133 	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
134 
135 	switch (a->attr_id) {
136 	case attr_feature:
137 		return sysfs_emit(buf, "supported\n");
138 	case attr_pointer_ui:
139 		if (!ptr)
140 			return 0;
141 		return sysfs_emit(buf, "%u\n", *(unsigned int *)ptr);
142 	case attr_pointer_bool:
143 		if (!ptr)
144 			return 0;
145 		return sysfs_emit(buf, "%d\n", *(bool *)ptr);
146 	case attr_accel:
147 		return z_erofs_crypto_show_engines(buf, PAGE_SIZE, '\n');
148 	}
149 	return 0;
150 }
151 
152 static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
153 				const char *buf, size_t len)
154 {
155 	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
156 						s_kobj);
157 	struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
158 	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
159 	unsigned long t;
160 	int ret;
161 
162 	switch (a->attr_id) {
163 	case attr_pointer_ui:
164 		if (!ptr)
165 			return 0;
166 		ret = kstrtoul(skip_spaces(buf), 0, &t);
167 		if (ret)
168 			return ret;
169 		if (t != (unsigned int)t)
170 			return -ERANGE;
171 		if (IS_ENABLED(CONFIG_EROFS_FS_ZIP) &&
172 		    !strcmp(a->attr.name, "sync_decompress") &&
173 		    (t > EROFS_SYNC_DECOMPRESS_FORCE_OFF))
174 			return -EINVAL;
175 		*(unsigned int *)ptr = t;
176 		return len;
177 	case attr_pointer_bool:
178 		if (!ptr)
179 			return 0;
180 		ret = kstrtoul(skip_spaces(buf), 0, &t);
181 		if (ret)
182 			return ret;
183 		if (t != 0 && t != 1)
184 			return -EINVAL;
185 		*(bool *)ptr = !!t;
186 		return len;
187 #ifdef CONFIG_EROFS_FS_ZIP
188 	case attr_drop_caches:
189 		ret = kstrtoul(skip_spaces(buf), 0, &t);
190 		if (ret)
191 			return ret;
192 		if (t < 1 || t > 3)
193 			return -EINVAL;
194 
195 		if (t & 2)
196 			z_erofs_shrink_scan(sbi, ~0UL);
197 		if (t & 1)
198 			invalidate_mapping_pages(MNGD_MAPPING(sbi), 0, -1);
199 		return len;
200 #endif
201 #ifdef CONFIG_EROFS_FS_ZIP_ACCEL
202 	case attr_accel:
203 		buf = skip_spaces(buf);
204 		z_erofs_crypto_disable_all_engines();
205 		while (*buf) {
206 			t = strcspn(buf, "\n");
207 			ret = z_erofs_crypto_enable_engine(buf, t);
208 			if (ret < 0)
209 				return ret;
210 			buf += buf[t] != '\0' ? t + 1 : t;
211 		}
212 		return len;
213 #endif
214 	}
215 	return 0;
216 }
217 
218 static void erofs_sb_release(struct kobject *kobj)
219 {
220 	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
221 						 s_kobj);
222 	complete(&sbi->s_kobj_unregister);
223 }
224 
225 static const struct sysfs_ops erofs_attr_ops = {
226 	.show	= erofs_attr_show,
227 	.store	= erofs_attr_store,
228 };
229 
230 static const struct kobj_type erofs_sb_ktype = {
231 	.default_groups = erofs_sb_groups,
232 	.sysfs_ops	= &erofs_attr_ops,
233 	.release	= erofs_sb_release,
234 };
235 
236 static const struct kobj_type erofs_ktype = {
237 	.default_groups = erofs_groups,
238 	.sysfs_ops	= &erofs_attr_ops,
239 };
240 
241 static struct kset erofs_root = {
242 	.kobj	= {.ktype = &erofs_ktype},
243 };
244 
245 static const struct kobj_type erofs_feat_ktype = {
246 	.default_groups = erofs_feat_groups,
247 	.sysfs_ops	= &erofs_attr_ops,
248 };
249 
250 static struct kobject erofs_feat = {
251 	.kset	= &erofs_root,
252 };
253 
254 int erofs_register_sysfs(struct super_block *sb)
255 {
256 	struct erofs_sb_info *sbi = EROFS_SB(sb);
257 	int err;
258 
259 	sbi->s_kobj.kset = &erofs_root;
260 	init_completion(&sbi->s_kobj_unregister);
261 	err = kobject_init_and_add(&sbi->s_kobj, &erofs_sb_ktype, NULL, "%s",
262 				   sb->s_sysfs_name);
263 	if (err) {
264 		kobject_put(&sbi->s_kobj);
265 		wait_for_completion(&sbi->s_kobj_unregister);
266 	}
267 	return err;
268 }
269 
270 void erofs_unregister_sysfs(struct super_block *sb)
271 {
272 	struct erofs_sb_info *sbi = EROFS_SB(sb);
273 
274 	if (sbi->s_kobj.state_in_sysfs) {
275 		kobject_del(&sbi->s_kobj);
276 		kobject_put(&sbi->s_kobj);
277 		wait_for_completion(&sbi->s_kobj_unregister);
278 	}
279 }
280 
281 void erofs_exit_sysfs(void)
282 {
283 	kobject_put(&erofs_feat);
284 	kset_unregister(&erofs_root);
285 }
286 
287 int __init erofs_init_sysfs(void)
288 {
289 	int ret;
290 
291 	kobject_set_name(&erofs_root.kobj, "erofs");
292 	erofs_root.kobj.parent = fs_kobj;
293 	ret = kset_register(&erofs_root);
294 	if (!ret) {
295 		ret = kobject_init_and_add(&erofs_feat, &erofs_feat_ktype,
296 					   NULL, "features");
297 		if (!ret)
298 			return 0;
299 		erofs_exit_sysfs();
300 	}
301 	return ret;
302 }
303