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_NOFS); 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(struct f2fs_sb_info *sbi, 113 const struct posix_acl *acl, size_t *size) 114 { 115 struct f2fs_acl_header *f2fs_acl; 116 struct f2fs_acl_entry *entry; 117 int i; 118 119 f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) + 120 acl->a_count * sizeof(struct f2fs_acl_entry), 121 GFP_NOFS); 122 if (!f2fs_acl) 123 return ERR_PTR(-ENOMEM); 124 125 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); 126 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); 127 128 for (i = 0; i < acl->a_count; i++) { 129 130 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag); 131 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); 132 133 switch (acl->a_entries[i].e_tag) { 134 case ACL_USER: 135 entry->e_id = cpu_to_le32( 136 from_kuid(&init_user_ns, 137 acl->a_entries[i].e_uid)); 138 entry = (struct f2fs_acl_entry *)((char *)entry + 139 sizeof(struct f2fs_acl_entry)); 140 break; 141 case ACL_GROUP: 142 entry->e_id = cpu_to_le32( 143 from_kgid(&init_user_ns, 144 acl->a_entries[i].e_gid)); 145 entry = (struct f2fs_acl_entry *)((char *)entry + 146 sizeof(struct f2fs_acl_entry)); 147 break; 148 case ACL_USER_OBJ: 149 case ACL_GROUP_OBJ: 150 case ACL_MASK: 151 case ACL_OTHER: 152 entry = (struct f2fs_acl_entry *)((char *)entry + 153 sizeof(struct f2fs_acl_entry_short)); 154 break; 155 default: 156 goto fail; 157 } 158 } 159 *size = f2fs_acl_size(acl->a_count); 160 return (void *)f2fs_acl; 161 162 fail: 163 kfree(f2fs_acl); 164 return ERR_PTR(-EINVAL); 165 } 166 167 static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type, 168 struct page *dpage) 169 { 170 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 171 void *value = NULL; 172 struct posix_acl *acl; 173 int retval; 174 175 if (type == ACL_TYPE_ACCESS) 176 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 177 178 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage); 179 if (retval > 0) { 180 value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO); 181 if (!value) 182 return ERR_PTR(-ENOMEM); 183 retval = f2fs_getxattr(inode, name_index, "", value, 184 retval, dpage); 185 } 186 187 if (retval > 0) 188 acl = f2fs_acl_from_disk(value, retval); 189 else if (retval == -ENODATA) 190 acl = NULL; 191 else 192 acl = ERR_PTR(retval); 193 kfree(value); 194 195 return acl; 196 } 197 198 struct posix_acl *f2fs_get_acl(struct inode *inode, int type) 199 { 200 return __f2fs_get_acl(inode, type, NULL); 201 } 202 203 static int __f2fs_set_acl(struct inode *inode, int type, 204 struct posix_acl *acl, struct page *ipage) 205 { 206 int name_index; 207 void *value = NULL; 208 size_t size = 0; 209 int error; 210 211 switch (type) { 212 case ACL_TYPE_ACCESS: 213 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 214 if (acl) { 215 error = posix_acl_equiv_mode(acl, &inode->i_mode); 216 if (error < 0) 217 return error; 218 set_acl_inode(inode, inode->i_mode); 219 if (error == 0) 220 acl = NULL; 221 } 222 break; 223 224 case ACL_TYPE_DEFAULT: 225 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 226 if (!S_ISDIR(inode->i_mode)) 227 return acl ? -EACCES : 0; 228 break; 229 230 default: 231 return -EINVAL; 232 } 233 234 if (acl) { 235 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); 236 if (IS_ERR(value)) { 237 clear_inode_flag(inode, FI_ACL_MODE); 238 return (int)PTR_ERR(value); 239 } 240 } 241 242 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); 243 244 kfree(value); 245 if (!error) 246 set_cached_acl(inode, type, acl); 247 248 clear_inode_flag(inode, FI_ACL_MODE); 249 return error; 250 } 251 252 int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type) 253 { 254 return __f2fs_set_acl(inode, type, acl, NULL); 255 } 256 257 /* 258 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create 259 * are copied from posix_acl.c 260 */ 261 static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, 262 gfp_t flags) 263 { 264 struct posix_acl *clone = NULL; 265 266 if (acl) { 267 int size = sizeof(struct posix_acl) + acl->a_count * 268 sizeof(struct posix_acl_entry); 269 clone = kmemdup(acl, size, flags); 270 if (clone) 271 atomic_set(&clone->a_refcount, 1); 272 } 273 return clone; 274 } 275 276 static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) 277 { 278 struct posix_acl_entry *pa, *pe; 279 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; 280 umode_t mode = *mode_p; 281 int not_equiv = 0; 282 283 /* assert(atomic_read(acl->a_refcount) == 1); */ 284 285 FOREACH_ACL_ENTRY(pa, acl, pe) { 286 switch(pa->e_tag) { 287 case ACL_USER_OBJ: 288 pa->e_perm &= (mode >> 6) | ~S_IRWXO; 289 mode &= (pa->e_perm << 6) | ~S_IRWXU; 290 break; 291 292 case ACL_USER: 293 case ACL_GROUP: 294 not_equiv = 1; 295 break; 296 297 case ACL_GROUP_OBJ: 298 group_obj = pa; 299 break; 300 301 case ACL_OTHER: 302 pa->e_perm &= mode | ~S_IRWXO; 303 mode &= pa->e_perm | ~S_IRWXO; 304 break; 305 306 case ACL_MASK: 307 mask_obj = pa; 308 not_equiv = 1; 309 break; 310 311 default: 312 return -EIO; 313 } 314 } 315 316 if (mask_obj) { 317 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 318 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; 319 } else { 320 if (!group_obj) 321 return -EIO; 322 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 323 mode &= (group_obj->e_perm << 3) | ~S_IRWXG; 324 } 325 326 *mode_p = (*mode_p & ~S_IRWXUGO) | mode; 327 return not_equiv; 328 } 329 330 static int f2fs_acl_create(struct inode *dir, umode_t *mode, 331 struct posix_acl **default_acl, struct posix_acl **acl, 332 struct page *dpage) 333 { 334 struct posix_acl *p; 335 struct posix_acl *clone; 336 int ret; 337 338 *acl = NULL; 339 *default_acl = NULL; 340 341 if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) 342 return 0; 343 344 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); 345 if (!p || p == ERR_PTR(-EOPNOTSUPP)) { 346 *mode &= ~current_umask(); 347 return 0; 348 } 349 if (IS_ERR(p)) 350 return PTR_ERR(p); 351 352 clone = f2fs_acl_clone(p, GFP_NOFS); 353 if (!clone) 354 goto no_mem; 355 356 ret = f2fs_acl_create_masq(clone, mode); 357 if (ret < 0) 358 goto no_mem_clone; 359 360 if (ret == 0) 361 posix_acl_release(clone); 362 else 363 *acl = clone; 364 365 if (!S_ISDIR(*mode)) 366 posix_acl_release(p); 367 else 368 *default_acl = p; 369 370 return 0; 371 372 no_mem_clone: 373 posix_acl_release(clone); 374 no_mem: 375 posix_acl_release(p); 376 return -ENOMEM; 377 } 378 379 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, 380 struct page *dpage) 381 { 382 struct posix_acl *default_acl = NULL, *acl = NULL; 383 int error = 0; 384 385 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); 386 if (error) 387 return error; 388 389 f2fs_mark_inode_dirty_sync(inode); 390 391 if (default_acl) { 392 error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl, 393 ipage); 394 posix_acl_release(default_acl); 395 } 396 if (acl) { 397 if (!error) 398 error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, 399 ipage); 400 posix_acl_release(acl); 401 } 402 403 return error; 404 } 405