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 umode_t mode = inode->i_mode; 211 212 switch (type) { 213 case ACL_TYPE_ACCESS: 214 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 215 if (acl && !ipage) { 216 error = posix_acl_update_mode(inode, &mode, &acl); 217 if (error) 218 return error; 219 set_acl_inode(inode, mode); 220 } 221 break; 222 223 case ACL_TYPE_DEFAULT: 224 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 225 if (!S_ISDIR(inode->i_mode)) 226 return acl ? -EACCES : 0; 227 break; 228 229 default: 230 return -EINVAL; 231 } 232 233 if (acl) { 234 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); 235 if (IS_ERR(value)) { 236 clear_inode_flag(inode, FI_ACL_MODE); 237 return PTR_ERR(value); 238 } 239 } 240 241 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); 242 243 kfree(value); 244 if (!error) 245 set_cached_acl(inode, type, acl); 246 247 clear_inode_flag(inode, FI_ACL_MODE); 248 return error; 249 } 250 251 int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type) 252 { 253 return __f2fs_set_acl(inode, type, acl, NULL); 254 } 255 256 /* 257 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create 258 * are copied from posix_acl.c 259 */ 260 static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, 261 gfp_t flags) 262 { 263 struct posix_acl *clone = NULL; 264 265 if (acl) { 266 int size = sizeof(struct posix_acl) + acl->a_count * 267 sizeof(struct posix_acl_entry); 268 clone = kmemdup(acl, size, flags); 269 if (clone) 270 atomic_set(&clone->a_refcount, 1); 271 } 272 return clone; 273 } 274 275 static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) 276 { 277 struct posix_acl_entry *pa, *pe; 278 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; 279 umode_t mode = *mode_p; 280 int not_equiv = 0; 281 282 /* assert(atomic_read(acl->a_refcount) == 1); */ 283 284 FOREACH_ACL_ENTRY(pa, acl, pe) { 285 switch(pa->e_tag) { 286 case ACL_USER_OBJ: 287 pa->e_perm &= (mode >> 6) | ~S_IRWXO; 288 mode &= (pa->e_perm << 6) | ~S_IRWXU; 289 break; 290 291 case ACL_USER: 292 case ACL_GROUP: 293 not_equiv = 1; 294 break; 295 296 case ACL_GROUP_OBJ: 297 group_obj = pa; 298 break; 299 300 case ACL_OTHER: 301 pa->e_perm &= mode | ~S_IRWXO; 302 mode &= pa->e_perm | ~S_IRWXO; 303 break; 304 305 case ACL_MASK: 306 mask_obj = pa; 307 not_equiv = 1; 308 break; 309 310 default: 311 return -EIO; 312 } 313 } 314 315 if (mask_obj) { 316 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 317 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; 318 } else { 319 if (!group_obj) 320 return -EIO; 321 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 322 mode &= (group_obj->e_perm << 3) | ~S_IRWXG; 323 } 324 325 *mode_p = (*mode_p & ~S_IRWXUGO) | mode; 326 return not_equiv; 327 } 328 329 static int f2fs_acl_create(struct inode *dir, umode_t *mode, 330 struct posix_acl **default_acl, struct posix_acl **acl, 331 struct page *dpage) 332 { 333 struct posix_acl *p; 334 struct posix_acl *clone; 335 int ret; 336 337 *acl = NULL; 338 *default_acl = NULL; 339 340 if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) 341 return 0; 342 343 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); 344 if (!p || p == ERR_PTR(-EOPNOTSUPP)) { 345 *mode &= ~current_umask(); 346 return 0; 347 } 348 if (IS_ERR(p)) 349 return PTR_ERR(p); 350 351 clone = f2fs_acl_clone(p, GFP_NOFS); 352 if (!clone) 353 goto no_mem; 354 355 ret = f2fs_acl_create_masq(clone, mode); 356 if (ret < 0) 357 goto no_mem_clone; 358 359 if (ret == 0) 360 posix_acl_release(clone); 361 else 362 *acl = clone; 363 364 if (!S_ISDIR(*mode)) 365 posix_acl_release(p); 366 else 367 *default_acl = p; 368 369 return 0; 370 371 no_mem_clone: 372 posix_acl_release(clone); 373 no_mem: 374 posix_acl_release(p); 375 return -ENOMEM; 376 } 377 378 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, 379 struct page *dpage) 380 { 381 struct posix_acl *default_acl = NULL, *acl = NULL; 382 int error = 0; 383 384 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); 385 if (error) 386 return error; 387 388 f2fs_mark_inode_dirty_sync(inode, true); 389 390 if (default_acl) { 391 error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl, 392 ipage); 393 posix_acl_release(default_acl); 394 } 395 if (acl) { 396 if (!error) 397 error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, 398 ipage); 399 posix_acl_release(acl); 400 } 401 402 return error; 403 } 404