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