1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> 4 */ 5 6 #include <linux/hashtable.h> 7 #include <linux/xattr.h> 8 #include "messages.h" 9 #include "props.h" 10 #include "btrfs_inode.h" 11 #include "transaction.h" 12 #include "ctree.h" 13 #include "xattr.h" 14 #include "compression.h" 15 #include "space-info.h" 16 #include "fs.h" 17 #include "accessors.h" 18 #include "super.h" 19 #include "dir-item.h" 20 21 #define BTRFS_PROP_HANDLERS_HT_BITS 8 22 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); 23 24 struct prop_handler { 25 struct hlist_node node; 26 const char *xattr_name; 27 int (*validate)(const struct btrfs_inode *inode, const char *value, 28 size_t len); 29 int (*apply)(struct inode *inode, const char *value, size_t len); 30 const char *(*extract)(struct inode *inode); 31 bool (*ignore)(const struct btrfs_inode *inode); 32 int inheritable; 33 }; 34 35 static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash) 36 { 37 struct hlist_head *h; 38 39 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)]; 40 if (hlist_empty(h)) 41 return NULL; 42 43 return h; 44 } 45 46 static const struct prop_handler * 47 find_prop_handler(const char *name, 48 const struct hlist_head *handlers) 49 { 50 struct prop_handler *h; 51 52 if (!handlers) { 53 u64 hash = btrfs_name_hash(name, strlen(name)); 54 55 handlers = find_prop_handlers_by_hash(hash); 56 if (!handlers) 57 return NULL; 58 } 59 60 hlist_for_each_entry(h, handlers, node) 61 if (!strcmp(h->xattr_name, name)) 62 return h; 63 64 return NULL; 65 } 66 67 int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name, 68 const char *value, size_t value_len) 69 { 70 const struct prop_handler *handler; 71 72 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) 73 return -EINVAL; 74 75 handler = find_prop_handler(name, NULL); 76 if (!handler) 77 return -EINVAL; 78 79 if (value_len == 0) 80 return 0; 81 82 return handler->validate(inode, value, value_len); 83 } 84 85 /* 86 * Check if a property should be ignored (not set) for an inode. 87 * 88 * @inode: The target inode. 89 * @name: The property's name. 90 * 91 * The caller must be sure the given property name is valid, for example by 92 * having previously called btrfs_validate_prop(). 93 * 94 * Returns: true if the property should be ignored for the given inode 95 * false if the property must not be ignored for the given inode 96 */ 97 bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name) 98 { 99 const struct prop_handler *handler; 100 101 handler = find_prop_handler(name, NULL); 102 ASSERT(handler != NULL); 103 104 return handler->ignore(inode); 105 } 106 107 int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, 108 const char *name, const char *value, size_t value_len, 109 int flags) 110 { 111 const struct prop_handler *handler; 112 int ret; 113 114 handler = find_prop_handler(name, NULL); 115 if (!handler) 116 return -EINVAL; 117 118 if (value_len == 0) { 119 ret = btrfs_setxattr(trans, inode, handler->xattr_name, 120 NULL, 0, flags); 121 if (ret) 122 return ret; 123 124 ret = handler->apply(inode, NULL, 0); 125 ASSERT(ret == 0); 126 127 return ret; 128 } 129 130 ret = btrfs_setxattr(trans, inode, handler->xattr_name, value, 131 value_len, flags); 132 if (ret) 133 return ret; 134 ret = handler->apply(inode, value, value_len); 135 if (ret) { 136 btrfs_setxattr(trans, inode, handler->xattr_name, NULL, 137 0, flags); 138 return ret; 139 } 140 141 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); 142 143 return 0; 144 } 145 146 static int iterate_object_props(struct btrfs_root *root, 147 struct btrfs_path *path, 148 u64 objectid, 149 void (*iterator)(void *, 150 const struct prop_handler *, 151 const char *, 152 size_t), 153 void *ctx) 154 { 155 int ret; 156 char *name_buf = NULL; 157 char *value_buf = NULL; 158 int name_buf_len = 0; 159 int value_buf_len = 0; 160 161 while (1) { 162 struct btrfs_key key; 163 struct btrfs_dir_item *di; 164 struct extent_buffer *leaf; 165 u32 total_len, cur, this_len; 166 int slot; 167 const struct hlist_head *handlers; 168 169 slot = path->slots[0]; 170 leaf = path->nodes[0]; 171 172 if (slot >= btrfs_header_nritems(leaf)) { 173 ret = btrfs_next_leaf(root, path); 174 if (ret < 0) 175 goto out; 176 else if (ret > 0) 177 break; 178 continue; 179 } 180 181 btrfs_item_key_to_cpu(leaf, &key, slot); 182 if (key.objectid != objectid) 183 break; 184 if (key.type != BTRFS_XATTR_ITEM_KEY) 185 break; 186 187 handlers = find_prop_handlers_by_hash(key.offset); 188 if (!handlers) 189 goto next_slot; 190 191 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 192 cur = 0; 193 total_len = btrfs_item_size(leaf, slot); 194 195 while (cur < total_len) { 196 u32 name_len = btrfs_dir_name_len(leaf, di); 197 u32 data_len = btrfs_dir_data_len(leaf, di); 198 unsigned long name_ptr, data_ptr; 199 const struct prop_handler *handler; 200 201 this_len = sizeof(*di) + name_len + data_len; 202 name_ptr = (unsigned long)(di + 1); 203 data_ptr = name_ptr + name_len; 204 205 if (name_len <= XATTR_BTRFS_PREFIX_LEN || 206 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX, 207 name_ptr, 208 XATTR_BTRFS_PREFIX_LEN)) 209 goto next_dir_item; 210 211 if (name_len >= name_buf_len) { 212 kfree(name_buf); 213 name_buf_len = name_len + 1; 214 name_buf = kmalloc(name_buf_len, GFP_NOFS); 215 if (!name_buf) { 216 ret = -ENOMEM; 217 goto out; 218 } 219 } 220 read_extent_buffer(leaf, name_buf, name_ptr, name_len); 221 name_buf[name_len] = '\0'; 222 223 handler = find_prop_handler(name_buf, handlers); 224 if (!handler) 225 goto next_dir_item; 226 227 if (data_len > value_buf_len) { 228 kfree(value_buf); 229 value_buf_len = data_len; 230 value_buf = kmalloc(data_len, GFP_NOFS); 231 if (!value_buf) { 232 ret = -ENOMEM; 233 goto out; 234 } 235 } 236 read_extent_buffer(leaf, value_buf, data_ptr, data_len); 237 238 iterator(ctx, handler, value_buf, data_len); 239 next_dir_item: 240 cur += this_len; 241 di = (struct btrfs_dir_item *)((char *) di + this_len); 242 } 243 244 next_slot: 245 path->slots[0]++; 246 } 247 248 ret = 0; 249 out: 250 btrfs_release_path(path); 251 kfree(name_buf); 252 kfree(value_buf); 253 254 return ret; 255 } 256 257 static void inode_prop_iterator(void *ctx, 258 const struct prop_handler *handler, 259 const char *value, 260 size_t len) 261 { 262 struct inode *inode = ctx; 263 struct btrfs_root *root = BTRFS_I(inode)->root; 264 int ret; 265 266 ret = handler->apply(inode, value, len); 267 if (unlikely(ret)) 268 btrfs_warn(root->fs_info, 269 "error applying prop %s to ino %llu (root %llu): %d", 270 handler->xattr_name, btrfs_ino(BTRFS_I(inode)), 271 root->root_key.objectid, ret); 272 else 273 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); 274 } 275 276 int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) 277 { 278 struct btrfs_root *root = BTRFS_I(inode)->root; 279 u64 ino = btrfs_ino(BTRFS_I(inode)); 280 281 return iterate_object_props(root, path, ino, inode_prop_iterator, inode); 282 } 283 284 static int prop_compression_validate(const struct btrfs_inode *inode, 285 const char *value, size_t len) 286 { 287 if (!btrfs_inode_can_compress(inode)) 288 return -EINVAL; 289 290 if (!value) 291 return 0; 292 293 if (btrfs_compress_is_valid_type(value, len)) 294 return 0; 295 296 if ((len == 2 && strncmp("no", value, 2) == 0) || 297 (len == 4 && strncmp("none", value, 4) == 0)) 298 return 0; 299 300 return -EINVAL; 301 } 302 303 static int prop_compression_apply(struct inode *inode, const char *value, 304 size_t len) 305 { 306 struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); 307 int type; 308 309 /* Reset to defaults */ 310 if (len == 0) { 311 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; 312 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; 313 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; 314 return 0; 315 } 316 317 /* Set NOCOMPRESS flag */ 318 if ((len == 2 && strncmp("no", value, 2) == 0) || 319 (len == 4 && strncmp("none", value, 4) == 0)) { 320 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 321 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; 322 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; 323 324 return 0; 325 } 326 327 if (!strncmp("lzo", value, 3)) { 328 type = BTRFS_COMPRESS_LZO; 329 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO); 330 } else if (!strncmp("zlib", value, 4)) { 331 type = BTRFS_COMPRESS_ZLIB; 332 } else if (!strncmp("zstd", value, 4)) { 333 type = BTRFS_COMPRESS_ZSTD; 334 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD); 335 } else { 336 return -EINVAL; 337 } 338 339 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; 340 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; 341 BTRFS_I(inode)->prop_compress = type; 342 343 return 0; 344 } 345 346 static bool prop_compression_ignore(const struct btrfs_inode *inode) 347 { 348 /* 349 * Compression only has effect for regular files, and for directories 350 * we set it just to propagate it to new files created inside them. 351 * Everything else (symlinks, devices, sockets, fifos) is pointless as 352 * it will do nothing, so don't waste metadata space on a compression 353 * xattr for anything that is neither a file nor a directory. 354 */ 355 if (!S_ISREG(inode->vfs_inode.i_mode) && 356 !S_ISDIR(inode->vfs_inode.i_mode)) 357 return true; 358 359 return false; 360 } 361 362 static const char *prop_compression_extract(struct inode *inode) 363 { 364 switch (BTRFS_I(inode)->prop_compress) { 365 case BTRFS_COMPRESS_ZLIB: 366 case BTRFS_COMPRESS_LZO: 367 case BTRFS_COMPRESS_ZSTD: 368 return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress); 369 default: 370 break; 371 } 372 373 return NULL; 374 } 375 376 static struct prop_handler prop_handlers[] = { 377 { 378 .xattr_name = XATTR_BTRFS_PREFIX "compression", 379 .validate = prop_compression_validate, 380 .apply = prop_compression_apply, 381 .extract = prop_compression_extract, 382 .ignore = prop_compression_ignore, 383 .inheritable = 1 384 }, 385 }; 386 387 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans, 388 struct inode *inode, struct inode *parent) 389 { 390 struct btrfs_root *root = BTRFS_I(inode)->root; 391 struct btrfs_fs_info *fs_info = root->fs_info; 392 int ret; 393 int i; 394 bool need_reserve = false; 395 396 if (!test_bit(BTRFS_INODE_HAS_PROPS, 397 &BTRFS_I(parent)->runtime_flags)) 398 return 0; 399 400 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { 401 const struct prop_handler *h = &prop_handlers[i]; 402 const char *value; 403 u64 num_bytes = 0; 404 405 if (!h->inheritable) 406 continue; 407 408 if (h->ignore(BTRFS_I(inode))) 409 continue; 410 411 value = h->extract(parent); 412 if (!value) 413 continue; 414 415 /* 416 * This is not strictly necessary as the property should be 417 * valid, but in case it isn't, don't propagate it further. 418 */ 419 ret = h->validate(BTRFS_I(inode), value, strlen(value)); 420 if (ret) 421 continue; 422 423 /* 424 * Currently callers should be reserving 1 item for properties, 425 * since we only have 1 property that we currently support. If 426 * we add more in the future we need to try and reserve more 427 * space for them. But we should also revisit how we do space 428 * reservations if we do add more properties in the future. 429 */ 430 if (need_reserve) { 431 num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1); 432 ret = btrfs_block_rsv_add(fs_info, trans->block_rsv, 433 num_bytes, 434 BTRFS_RESERVE_NO_FLUSH); 435 if (ret) 436 return ret; 437 } 438 439 ret = btrfs_setxattr(trans, inode, h->xattr_name, value, 440 strlen(value), 0); 441 if (!ret) { 442 ret = h->apply(inode, value, strlen(value)); 443 if (ret) 444 btrfs_setxattr(trans, inode, h->xattr_name, 445 NULL, 0, 0); 446 else 447 set_bit(BTRFS_INODE_HAS_PROPS, 448 &BTRFS_I(inode)->runtime_flags); 449 } 450 451 if (need_reserve) { 452 btrfs_block_rsv_release(fs_info, trans->block_rsv, 453 num_bytes, NULL); 454 if (ret) 455 return ret; 456 } 457 need_reserve = true; 458 } 459 460 return 0; 461 } 462 463 int __init btrfs_props_init(void) 464 { 465 int i; 466 467 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { 468 struct prop_handler *p = &prop_handlers[i]; 469 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name)); 470 471 hash_add(prop_handlers_ht, &p->node, h); 472 } 473 return 0; 474 } 475 476