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 = XATTR_NAME_POSIX_ACL_ACCESS; 190 break; 191 case ACL_TYPE_DEFAULT: 192 name = XATTR_NAME_POSIX_ACL_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 return NULL; 202 return ERR_PTR(size); 203 } 204 205 value = kmalloc(size, GFP_NOFS); 206 if (!value) 207 return ERR_PTR(-ENOMEM); 208 209 retval = reiserfs_xattr_get(inode, name, value, size); 210 if (retval == -ENODATA || retval == -ENOSYS) { 211 /* 212 * This shouldn't actually happen as it should have 213 * been caught above.. but just in case 214 */ 215 acl = NULL; 216 } else if (retval < 0) { 217 acl = ERR_PTR(retval); 218 } else { 219 acl = reiserfs_posix_acl_from_disk(value, retval); 220 } 221 222 kfree(value); 223 return acl; 224 } 225 226 /* 227 * Inode operation set_posix_acl(). 228 * 229 * inode->i_mutex: down 230 * BKL held [before 2.5.x] 231 */ 232 static int 233 __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, 234 int type, struct posix_acl *acl) 235 { 236 char *name; 237 void *value = NULL; 238 size_t size = 0; 239 int error; 240 241 switch (type) { 242 case ACL_TYPE_ACCESS: 243 name = XATTR_NAME_POSIX_ACL_ACCESS; 244 if (acl) { 245 error = posix_acl_update_mode(inode, &inode->i_mode, &acl); 246 if (error) 247 return error; 248 } 249 break; 250 case ACL_TYPE_DEFAULT: 251 name = XATTR_NAME_POSIX_ACL_DEFAULT; 252 if (!S_ISDIR(inode->i_mode)) 253 return acl ? -EACCES : 0; 254 break; 255 default: 256 return -EINVAL; 257 } 258 259 if (acl) { 260 value = reiserfs_posix_acl_to_disk(acl, &size); 261 if (IS_ERR(value)) 262 return (int)PTR_ERR(value); 263 } 264 265 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); 266 267 /* 268 * Ensure that the inode gets dirtied if we're only using 269 * the mode bits and an old ACL didn't exist. We don't need 270 * to check if the inode is hashed here since we won't get 271 * called by reiserfs_inherit_default_acl(). 272 */ 273 if (error == -ENODATA) { 274 error = 0; 275 if (type == ACL_TYPE_ACCESS) { 276 inode->i_ctime = current_time(inode); 277 mark_inode_dirty(inode); 278 } 279 } 280 281 kfree(value); 282 283 if (!error) 284 set_cached_acl(inode, type, acl); 285 286 return error; 287 } 288 289 /* 290 * dir->i_mutex: locked, 291 * inode is new and not released into the wild yet 292 */ 293 int 294 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, 295 struct inode *dir, struct dentry *dentry, 296 struct inode *inode) 297 { 298 struct posix_acl *default_acl, *acl; 299 int err = 0; 300 301 /* ACLs only get applied to files and directories */ 302 if (S_ISLNK(inode->i_mode)) 303 return 0; 304 305 /* 306 * ACLs can only be used on "new" objects, so if it's an old object 307 * there is nothing to inherit from 308 */ 309 if (get_inode_sd_version(dir) == STAT_DATA_V1) 310 goto apply_umask; 311 312 /* 313 * Don't apply ACLs to objects in the .reiserfs_priv tree.. This 314 * would be useless since permissions are ignored, and a pain because 315 * it introduces locking cycles 316 */ 317 if (IS_PRIVATE(dir)) { 318 inode->i_flags |= S_PRIVATE; 319 goto apply_umask; 320 } 321 322 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); 323 if (err) 324 return err; 325 326 if (default_acl) { 327 err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, 328 default_acl); 329 posix_acl_release(default_acl); 330 } 331 if (acl) { 332 if (!err) 333 err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, 334 acl); 335 posix_acl_release(acl); 336 } 337 338 return err; 339 340 apply_umask: 341 /* no ACL, apply umask */ 342 inode->i_mode &= ~current_umask(); 343 return err; 344 } 345 346 /* This is used to cache the default acl before a new object is created. 347 * The biggest reason for this is to get an idea of how many blocks will 348 * actually be required for the create operation if we must inherit an ACL. 349 * An ACL write can add up to 3 object creations and an additional file write 350 * so we'd prefer not to reserve that many blocks in the journal if we can. 351 * It also has the advantage of not loading the ACL with a transaction open, 352 * this may seem silly, but if the owner of the directory is doing the 353 * creation, the ACL may not be loaded since the permissions wouldn't require 354 * it. 355 * We return the number of blocks required for the transaction. 356 */ 357 int reiserfs_cache_default_acl(struct inode *inode) 358 { 359 struct posix_acl *acl; 360 int nblocks = 0; 361 362 if (IS_PRIVATE(inode)) 363 return 0; 364 365 acl = get_acl(inode, ACL_TYPE_DEFAULT); 366 367 if (acl && !IS_ERR(acl)) { 368 int size = reiserfs_acl_size(acl->a_count); 369 370 /* Other xattrs can be created during inode creation. We don't 371 * want to claim too many blocks, so we check to see if we 372 * we need to create the tree to the xattrs, and then we 373 * just want two files. */ 374 nblocks = reiserfs_xattr_jcreate_nblocks(inode); 375 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); 376 377 REISERFS_I(inode)->i_flags |= i_has_xattr_dir; 378 379 /* We need to account for writes + bitmaps for two files */ 380 nblocks += reiserfs_xattr_nblocks(inode, size) * 4; 381 posix_acl_release(acl); 382 } 383 384 return nblocks; 385 } 386 387 /* 388 * Called under i_mutex 389 */ 390 int reiserfs_acl_chmod(struct inode *inode) 391 { 392 if (IS_PRIVATE(inode)) 393 return 0; 394 if (get_inode_sd_version(inode) == STAT_DATA_V1 || 395 !reiserfs_posixacl(inode->i_sb)) 396 return 0; 397 398 return posix_acl_chmod(inode, inode->i_mode); 399 } 400