1 #include <linux/capability.h> 2 #include <linux/fs.h> 3 #include <linux/posix_acl.h> 4 #include "reiserfs.h" 5 #include <linux/errno.h> 6 #include <linux/pagemap.h> 7 #include <linux/xattr.h> 8 #include <linux/slab.h> 9 #include <linux/posix_acl_xattr.h> 10 #include "xattr.h" 11 #include "acl.h" 12 #include <linux/uaccess.h> 13 14 static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, 15 struct inode *inode, int type, 16 struct posix_acl *acl); 17 18 19 int 20 reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) 21 { 22 int error, error2; 23 struct reiserfs_transaction_handle th; 24 size_t jcreate_blocks; 25 int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; 26 27 28 /* 29 * Pessimism: We can't assume that anything from the xattr root up 30 * has been created. 31 */ 32 33 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + 34 reiserfs_xattr_nblocks(inode, size) * 2; 35 36 reiserfs_write_lock(inode->i_sb); 37 error = journal_begin(&th, inode->i_sb, jcreate_blocks); 38 reiserfs_write_unlock(inode->i_sb); 39 if (error == 0) { 40 error = __reiserfs_set_acl(&th, inode, type, acl); 41 reiserfs_write_lock(inode->i_sb); 42 error2 = journal_end(&th); 43 reiserfs_write_unlock(inode->i_sb); 44 if (error2) 45 error = error2; 46 } 47 48 return error; 49 } 50 51 /* 52 * Convert from filesystem to in-memory representation. 53 */ 54 static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) 55 { 56 const char *end = (char *)value + size; 57 int n, count; 58 struct posix_acl *acl; 59 60 if (!value) 61 return NULL; 62 if (size < sizeof(reiserfs_acl_header)) 63 return ERR_PTR(-EINVAL); 64 if (((reiserfs_acl_header *) value)->a_version != 65 cpu_to_le32(REISERFS_ACL_VERSION)) 66 return ERR_PTR(-EINVAL); 67 value = (char *)value + sizeof(reiserfs_acl_header); 68 count = reiserfs_acl_count(size); 69 if (count < 0) 70 return ERR_PTR(-EINVAL); 71 if (count == 0) 72 return NULL; 73 acl = posix_acl_alloc(count, GFP_NOFS); 74 if (!acl) 75 return ERR_PTR(-ENOMEM); 76 for (n = 0; n < count; n++) { 77 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; 78 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) 79 goto fail; 80 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); 81 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); 82 switch (acl->a_entries[n].e_tag) { 83 case ACL_USER_OBJ: 84 case ACL_GROUP_OBJ: 85 case ACL_MASK: 86 case ACL_OTHER: 87 value = (char *)value + 88 sizeof(reiserfs_acl_entry_short); 89 break; 90 91 case ACL_USER: 92 value = (char *)value + sizeof(reiserfs_acl_entry); 93 if ((char *)value > end) 94 goto fail; 95 acl->a_entries[n].e_uid = 96 make_kuid(&init_user_ns, 97 le32_to_cpu(entry->e_id)); 98 break; 99 case ACL_GROUP: 100 value = (char *)value + sizeof(reiserfs_acl_entry); 101 if ((char *)value > end) 102 goto fail; 103 acl->a_entries[n].e_gid = 104 make_kgid(&init_user_ns, 105 le32_to_cpu(entry->e_id)); 106 break; 107 108 default: 109 goto fail; 110 } 111 } 112 if (value != end) 113 goto fail; 114 return acl; 115 116 fail: 117 posix_acl_release(acl); 118 return ERR_PTR(-EINVAL); 119 } 120 121 /* 122 * Convert from in-memory to filesystem representation. 123 */ 124 static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) 125 { 126 reiserfs_acl_header *ext_acl; 127 char *e; 128 int n; 129 130 *size = reiserfs_acl_size(acl->a_count); 131 ext_acl = kmalloc(sizeof(reiserfs_acl_header) + 132 acl->a_count * 133 sizeof(reiserfs_acl_entry), 134 GFP_NOFS); 135 if (!ext_acl) 136 return ERR_PTR(-ENOMEM); 137 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); 138 e = (char *)ext_acl + sizeof(reiserfs_acl_header); 139 for (n = 0; n < acl->a_count; n++) { 140 const struct posix_acl_entry *acl_e = &acl->a_entries[n]; 141 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; 142 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); 143 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); 144 switch (acl->a_entries[n].e_tag) { 145 case ACL_USER: 146 entry->e_id = cpu_to_le32( 147 from_kuid(&init_user_ns, acl_e->e_uid)); 148 e += sizeof(reiserfs_acl_entry); 149 break; 150 case ACL_GROUP: 151 entry->e_id = cpu_to_le32( 152 from_kgid(&init_user_ns, acl_e->e_gid)); 153 e += sizeof(reiserfs_acl_entry); 154 break; 155 156 case ACL_USER_OBJ: 157 case ACL_GROUP_OBJ: 158 case ACL_MASK: 159 case ACL_OTHER: 160 e += sizeof(reiserfs_acl_entry_short); 161 break; 162 163 default: 164 goto fail; 165 } 166 } 167 return (char *)ext_acl; 168 169 fail: 170 kfree(ext_acl); 171 return ERR_PTR(-EINVAL); 172 } 173 174 /* 175 * Inode operation get_posix_acl(). 176 * 177 * inode->i_mutex: down 178 * BKL held [before 2.5.x] 179 */ 180 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) 181 { 182 char *name, *value; 183 struct posix_acl *acl; 184 int size; 185 int retval; 186 187 switch (type) { 188 case ACL_TYPE_ACCESS: 189 name = POSIX_ACL_XATTR_ACCESS; 190 break; 191 case ACL_TYPE_DEFAULT: 192 name = POSIX_ACL_XATTR_DEFAULT; 193 break; 194 default: 195 BUG(); 196 } 197 198 size = reiserfs_xattr_get(inode, name, NULL, 0); 199 if (size < 0) { 200 if (size == -ENODATA || size == -ENOSYS) { 201 set_cached_acl(inode, type, NULL); 202 return NULL; 203 } 204 return ERR_PTR(size); 205 } 206 207 value = kmalloc(size, GFP_NOFS); 208 if (!value) 209 return ERR_PTR(-ENOMEM); 210 211 retval = reiserfs_xattr_get(inode, name, value, size); 212 if (retval == -ENODATA || retval == -ENOSYS) { 213 /* 214 * This shouldn't actually happen as it should have 215 * been caught above.. but just in case 216 */ 217 acl = NULL; 218 } else if (retval < 0) { 219 acl = ERR_PTR(retval); 220 } else { 221 acl = reiserfs_posix_acl_from_disk(value, retval); 222 } 223 if (!IS_ERR(acl)) 224 set_cached_acl(inode, type, acl); 225 226 kfree(value); 227 return acl; 228 } 229 230 /* 231 * Inode operation set_posix_acl(). 232 * 233 * inode->i_mutex: down 234 * BKL held [before 2.5.x] 235 */ 236 static int 237 __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, 238 int type, struct posix_acl *acl) 239 { 240 char *name; 241 void *value = NULL; 242 size_t size = 0; 243 int error; 244 245 switch (type) { 246 case ACL_TYPE_ACCESS: 247 name = POSIX_ACL_XATTR_ACCESS; 248 if (acl) { 249 error = posix_acl_equiv_mode(acl, &inode->i_mode); 250 if (error < 0) 251 return error; 252 else { 253 if (error == 0) 254 acl = NULL; 255 } 256 } 257 break; 258 case ACL_TYPE_DEFAULT: 259 name = POSIX_ACL_XATTR_DEFAULT; 260 if (!S_ISDIR(inode->i_mode)) 261 return acl ? -EACCES : 0; 262 break; 263 default: 264 return -EINVAL; 265 } 266 267 if (acl) { 268 value = reiserfs_posix_acl_to_disk(acl, &size); 269 if (IS_ERR(value)) 270 return (int)PTR_ERR(value); 271 } 272 273 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); 274 275 /* 276 * Ensure that the inode gets dirtied if we're only using 277 * the mode bits and an old ACL didn't exist. We don't need 278 * to check if the inode is hashed here since we won't get 279 * called by reiserfs_inherit_default_acl(). 280 */ 281 if (error == -ENODATA) { 282 error = 0; 283 if (type == ACL_TYPE_ACCESS) { 284 inode->i_ctime = CURRENT_TIME_SEC; 285 mark_inode_dirty(inode); 286 } 287 } 288 289 kfree(value); 290 291 if (!error) 292 set_cached_acl(inode, type, acl); 293 294 return error; 295 } 296 297 /* 298 * dir->i_mutex: locked, 299 * inode is new and not released into the wild yet 300 */ 301 int 302 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, 303 struct inode *dir, struct dentry *dentry, 304 struct inode *inode) 305 { 306 struct posix_acl *default_acl, *acl; 307 int err = 0; 308 309 /* ACLs only get applied to files and directories */ 310 if (S_ISLNK(inode->i_mode)) 311 return 0; 312 313 /* 314 * ACLs can only be used on "new" objects, so if it's an old object 315 * there is nothing to inherit from 316 */ 317 if (get_inode_sd_version(dir) == STAT_DATA_V1) 318 goto apply_umask; 319 320 /* 321 * Don't apply ACLs to objects in the .reiserfs_priv tree.. This 322 * would be useless since permissions are ignored, and a pain because 323 * it introduces locking cycles 324 */ 325 if (IS_PRIVATE(dir)) { 326 inode->i_flags |= S_PRIVATE; 327 goto apply_umask; 328 } 329 330 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); 331 if (err) 332 return err; 333 334 if (default_acl) { 335 err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, 336 default_acl); 337 posix_acl_release(default_acl); 338 } 339 if (acl) { 340 if (!err) 341 err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, 342 acl); 343 posix_acl_release(acl); 344 } 345 346 return err; 347 348 apply_umask: 349 /* no ACL, apply umask */ 350 inode->i_mode &= ~current_umask(); 351 return err; 352 } 353 354 /* This is used to cache the default acl before a new object is created. 355 * The biggest reason for this is to get an idea of how many blocks will 356 * actually be required for the create operation if we must inherit an ACL. 357 * An ACL write can add up to 3 object creations and an additional file write 358 * so we'd prefer not to reserve that many blocks in the journal if we can. 359 * It also has the advantage of not loading the ACL with a transaction open, 360 * this may seem silly, but if the owner of the directory is doing the 361 * creation, the ACL may not be loaded since the permissions wouldn't require 362 * it. 363 * We return the number of blocks required for the transaction. 364 */ 365 int reiserfs_cache_default_acl(struct inode *inode) 366 { 367 struct posix_acl *acl; 368 int nblocks = 0; 369 370 if (IS_PRIVATE(inode)) 371 return 0; 372 373 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT); 374 375 if (acl && !IS_ERR(acl)) { 376 int size = reiserfs_acl_size(acl->a_count); 377 378 /* Other xattrs can be created during inode creation. We don't 379 * want to claim too many blocks, so we check to see if we 380 * we need to create the tree to the xattrs, and then we 381 * just want two files. */ 382 nblocks = reiserfs_xattr_jcreate_nblocks(inode); 383 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); 384 385 REISERFS_I(inode)->i_flags |= i_has_xattr_dir; 386 387 /* We need to account for writes + bitmaps for two files */ 388 nblocks += reiserfs_xattr_nblocks(inode, size) * 4; 389 posix_acl_release(acl); 390 } 391 392 return nblocks; 393 } 394 395 /* 396 * Called under i_mutex 397 */ 398 int reiserfs_acl_chmod(struct inode *inode) 399 { 400 if (IS_PRIVATE(inode)) 401 return 0; 402 if (get_inode_sd_version(inode) == STAT_DATA_V1 || 403 !reiserfs_posixacl(inode->i_sb)) 404 return 0; 405 406 return posix_acl_chmod(inode, inode->i_mode); 407 } 408