1 /* 2 * fs/f2fs/acl.c 3 * 4 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 5 * http://www.samsung.com/ 6 * 7 * Portions of this code from linux/fs/ext2/acl.c 8 * 9 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 #include <linux/f2fs_fs.h> 16 #include "f2fs.h" 17 #include "xattr.h" 18 #include "acl.h" 19 20 static inline size_t f2fs_acl_size(int count) 21 { 22 if (count <= 4) { 23 return sizeof(struct f2fs_acl_header) + 24 count * sizeof(struct f2fs_acl_entry_short); 25 } else { 26 return sizeof(struct f2fs_acl_header) + 27 4 * sizeof(struct f2fs_acl_entry_short) + 28 (count - 4) * sizeof(struct f2fs_acl_entry); 29 } 30 } 31 32 static inline int f2fs_acl_count(size_t size) 33 { 34 ssize_t s; 35 size -= sizeof(struct f2fs_acl_header); 36 s = size - 4 * sizeof(struct f2fs_acl_entry_short); 37 if (s < 0) { 38 if (size % sizeof(struct f2fs_acl_entry_short)) 39 return -1; 40 return size / sizeof(struct f2fs_acl_entry_short); 41 } else { 42 if (s % sizeof(struct f2fs_acl_entry)) 43 return -1; 44 return s / sizeof(struct f2fs_acl_entry) + 4; 45 } 46 } 47 48 static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size) 49 { 50 int i, count; 51 struct posix_acl *acl; 52 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value; 53 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1); 54 const char *end = value + size; 55 56 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION)) 57 return ERR_PTR(-EINVAL); 58 59 count = f2fs_acl_count(size); 60 if (count < 0) 61 return ERR_PTR(-EINVAL); 62 if (count == 0) 63 return NULL; 64 65 acl = posix_acl_alloc(count, GFP_KERNEL); 66 if (!acl) 67 return ERR_PTR(-ENOMEM); 68 69 for (i = 0; i < count; i++) { 70 71 if ((char *)entry > end) 72 goto fail; 73 74 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag); 75 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm); 76 77 switch (acl->a_entries[i].e_tag) { 78 case ACL_USER_OBJ: 79 case ACL_GROUP_OBJ: 80 case ACL_MASK: 81 case ACL_OTHER: 82 entry = (struct f2fs_acl_entry *)((char *)entry + 83 sizeof(struct f2fs_acl_entry_short)); 84 break; 85 86 case ACL_USER: 87 acl->a_entries[i].e_uid = 88 make_kuid(&init_user_ns, 89 le32_to_cpu(entry->e_id)); 90 entry = (struct f2fs_acl_entry *)((char *)entry + 91 sizeof(struct f2fs_acl_entry)); 92 break; 93 case ACL_GROUP: 94 acl->a_entries[i].e_gid = 95 make_kgid(&init_user_ns, 96 le32_to_cpu(entry->e_id)); 97 entry = (struct f2fs_acl_entry *)((char *)entry + 98 sizeof(struct f2fs_acl_entry)); 99 break; 100 default: 101 goto fail; 102 } 103 } 104 if ((char *)entry != end) 105 goto fail; 106 return acl; 107 fail: 108 posix_acl_release(acl); 109 return ERR_PTR(-EINVAL); 110 } 111 112 static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size) 113 { 114 struct f2fs_acl_header *f2fs_acl; 115 struct f2fs_acl_entry *entry; 116 int i; 117 118 f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count * 119 sizeof(struct f2fs_acl_entry), GFP_KERNEL); 120 if (!f2fs_acl) 121 return ERR_PTR(-ENOMEM); 122 123 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); 124 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); 125 126 for (i = 0; i < acl->a_count; i++) { 127 128 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag); 129 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); 130 131 switch (acl->a_entries[i].e_tag) { 132 case ACL_USER: 133 entry->e_id = cpu_to_le32( 134 from_kuid(&init_user_ns, 135 acl->a_entries[i].e_uid)); 136 entry = (struct f2fs_acl_entry *)((char *)entry + 137 sizeof(struct f2fs_acl_entry)); 138 break; 139 case ACL_GROUP: 140 entry->e_id = cpu_to_le32( 141 from_kgid(&init_user_ns, 142 acl->a_entries[i].e_gid)); 143 entry = (struct f2fs_acl_entry *)((char *)entry + 144 sizeof(struct f2fs_acl_entry)); 145 break; 146 case ACL_USER_OBJ: 147 case ACL_GROUP_OBJ: 148 case ACL_MASK: 149 case ACL_OTHER: 150 entry = (struct f2fs_acl_entry *)((char *)entry + 151 sizeof(struct f2fs_acl_entry_short)); 152 break; 153 default: 154 goto fail; 155 } 156 } 157 *size = f2fs_acl_size(acl->a_count); 158 return (void *)f2fs_acl; 159 160 fail: 161 kfree(f2fs_acl); 162 return ERR_PTR(-EINVAL); 163 } 164 165 struct posix_acl *f2fs_get_acl(struct inode *inode, int type) 166 { 167 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 168 void *value = NULL; 169 struct posix_acl *acl; 170 int retval; 171 172 if (type == ACL_TYPE_ACCESS) 173 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 174 175 retval = f2fs_getxattr(inode, name_index, "", NULL, 0); 176 if (retval > 0) { 177 value = kmalloc(retval, GFP_KERNEL); 178 if (!value) 179 return ERR_PTR(-ENOMEM); 180 retval = f2fs_getxattr(inode, name_index, "", value, retval); 181 } 182 183 if (retval > 0) 184 acl = f2fs_acl_from_disk(value, retval); 185 else if (retval == -ENODATA) 186 acl = NULL; 187 else 188 acl = ERR_PTR(retval); 189 kfree(value); 190 191 if (!IS_ERR(acl)) 192 set_cached_acl(inode, type, acl); 193 194 return acl; 195 } 196 197 static int __f2fs_set_acl(struct inode *inode, int type, 198 struct posix_acl *acl, struct page *ipage) 199 { 200 struct f2fs_inode_info *fi = F2FS_I(inode); 201 int name_index; 202 void *value = NULL; 203 size_t size = 0; 204 int error; 205 206 switch (type) { 207 case ACL_TYPE_ACCESS: 208 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 209 if (acl) { 210 error = posix_acl_equiv_mode(acl, &inode->i_mode); 211 if (error < 0) 212 return error; 213 set_acl_inode(fi, inode->i_mode); 214 if (error == 0) 215 acl = NULL; 216 } 217 break; 218 219 case ACL_TYPE_DEFAULT: 220 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 221 if (!S_ISDIR(inode->i_mode)) 222 return acl ? -EACCES : 0; 223 break; 224 225 default: 226 return -EINVAL; 227 } 228 229 if (acl) { 230 value = f2fs_acl_to_disk(acl, &size); 231 if (IS_ERR(value)) { 232 cond_clear_inode_flag(fi, FI_ACL_MODE); 233 return (int)PTR_ERR(value); 234 } 235 } 236 237 error = f2fs_setxattr(inode, name_index, "", value, size, ipage); 238 239 kfree(value); 240 if (!error) 241 set_cached_acl(inode, type, acl); 242 243 cond_clear_inode_flag(fi, FI_ACL_MODE); 244 return error; 245 } 246 247 int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type) 248 { 249 return __f2fs_set_acl(inode, type, acl, NULL); 250 } 251 252 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage) 253 { 254 struct posix_acl *default_acl, *acl; 255 int error = 0; 256 257 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); 258 if (error) 259 return error; 260 261 if (default_acl) { 262 error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl, 263 ipage); 264 posix_acl_release(default_acl); 265 } 266 if (acl) { 267 if (error) 268 error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, 269 ipage); 270 posix_acl_release(acl); 271 } 272 273 return error; 274 } 275