1 /* 2 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/hashtable.h> 20 #include "props.h" 21 #include "btrfs_inode.h" 22 #include "hash.h" 23 #include "transaction.h" 24 #include "xattr.h" 25 #include "compression.h" 26 27 #define BTRFS_PROP_HANDLERS_HT_BITS 8 28 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); 29 30 struct prop_handler { 31 struct hlist_node node; 32 const char *xattr_name; 33 int (*validate)(const char *value, size_t len); 34 int (*apply)(struct inode *inode, const char *value, size_t len); 35 const char *(*extract)(struct inode *inode); 36 int inheritable; 37 }; 38 39 static int prop_compression_validate(const char *value, size_t len); 40 static int prop_compression_apply(struct inode *inode, 41 const char *value, 42 size_t len); 43 static const char *prop_compression_extract(struct inode *inode); 44 45 static struct prop_handler prop_handlers[] = { 46 { 47 .xattr_name = XATTR_BTRFS_PREFIX "compression", 48 .validate = prop_compression_validate, 49 .apply = prop_compression_apply, 50 .extract = prop_compression_extract, 51 .inheritable = 1 52 }, 53 }; 54 55 void __init btrfs_props_init(void) 56 { 57 int i; 58 59 hash_init(prop_handlers_ht); 60 61 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { 62 struct prop_handler *p = &prop_handlers[i]; 63 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name)); 64 65 hash_add(prop_handlers_ht, &p->node, h); 66 } 67 } 68 69 static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash) 70 { 71 struct hlist_head *h; 72 73 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)]; 74 if (hlist_empty(h)) 75 return NULL; 76 77 return h; 78 } 79 80 static const struct prop_handler * 81 find_prop_handler(const char *name, 82 const struct hlist_head *handlers) 83 { 84 struct prop_handler *h; 85 86 if (!handlers) { 87 u64 hash = btrfs_name_hash(name, strlen(name)); 88 89 handlers = find_prop_handlers_by_hash(hash); 90 if (!handlers) 91 return NULL; 92 } 93 94 hlist_for_each_entry(h, handlers, node) 95 if (!strcmp(h->xattr_name, name)) 96 return h; 97 98 return NULL; 99 } 100 101 static int __btrfs_set_prop(struct btrfs_trans_handle *trans, 102 struct inode *inode, 103 const char *name, 104 const char *value, 105 size_t value_len, 106 int flags) 107 { 108 const struct prop_handler *handler; 109 int ret; 110 111 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) 112 return -EINVAL; 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 = handler->validate(value, value_len); 131 if (ret) 132 return ret; 133 ret = __btrfs_setxattr(trans, inode, handler->xattr_name, 134 value, value_len, flags); 135 if (ret) 136 return ret; 137 ret = handler->apply(inode, value, value_len); 138 if (ret) { 139 __btrfs_setxattr(trans, inode, handler->xattr_name, 140 NULL, 0, flags); 141 return ret; 142 } 143 144 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); 145 146 return 0; 147 } 148 149 int btrfs_set_prop(struct inode *inode, 150 const char *name, 151 const char *value, 152 size_t value_len, 153 int flags) 154 { 155 return __btrfs_set_prop(NULL, inode, name, value, value_len, flags); 156 } 157 158 static int iterate_object_props(struct btrfs_root *root, 159 struct btrfs_path *path, 160 u64 objectid, 161 void (*iterator)(void *, 162 const struct prop_handler *, 163 const char *, 164 size_t), 165 void *ctx) 166 { 167 int ret; 168 char *name_buf = NULL; 169 char *value_buf = NULL; 170 int name_buf_len = 0; 171 int value_buf_len = 0; 172 173 while (1) { 174 struct btrfs_key key; 175 struct btrfs_dir_item *di; 176 struct extent_buffer *leaf; 177 u32 total_len, cur, this_len; 178 int slot; 179 const struct hlist_head *handlers; 180 181 slot = path->slots[0]; 182 leaf = path->nodes[0]; 183 184 if (slot >= btrfs_header_nritems(leaf)) { 185 ret = btrfs_next_leaf(root, path); 186 if (ret < 0) 187 goto out; 188 else if (ret > 0) 189 break; 190 continue; 191 } 192 193 btrfs_item_key_to_cpu(leaf, &key, slot); 194 if (key.objectid != objectid) 195 break; 196 if (key.type != BTRFS_XATTR_ITEM_KEY) 197 break; 198 199 handlers = find_prop_handlers_by_hash(key.offset); 200 if (!handlers) 201 goto next_slot; 202 203 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 204 cur = 0; 205 total_len = btrfs_item_size_nr(leaf, slot); 206 207 while (cur < total_len) { 208 u32 name_len = btrfs_dir_name_len(leaf, di); 209 u32 data_len = btrfs_dir_data_len(leaf, di); 210 unsigned long name_ptr, data_ptr; 211 const struct prop_handler *handler; 212 213 this_len = sizeof(*di) + name_len + data_len; 214 name_ptr = (unsigned long)(di + 1); 215 data_ptr = name_ptr + name_len; 216 217 if (name_len <= XATTR_BTRFS_PREFIX_LEN || 218 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX, 219 name_ptr, 220 XATTR_BTRFS_PREFIX_LEN)) 221 goto next_dir_item; 222 223 if (name_len >= name_buf_len) { 224 kfree(name_buf); 225 name_buf_len = name_len + 1; 226 name_buf = kmalloc(name_buf_len, GFP_NOFS); 227 if (!name_buf) { 228 ret = -ENOMEM; 229 goto out; 230 } 231 } 232 read_extent_buffer(leaf, name_buf, name_ptr, name_len); 233 name_buf[name_len] = '\0'; 234 235 handler = find_prop_handler(name_buf, handlers); 236 if (!handler) 237 goto next_dir_item; 238 239 if (data_len > value_buf_len) { 240 kfree(value_buf); 241 value_buf_len = data_len; 242 value_buf = kmalloc(data_len, GFP_NOFS); 243 if (!value_buf) { 244 ret = -ENOMEM; 245 goto out; 246 } 247 } 248 read_extent_buffer(leaf, value_buf, data_ptr, data_len); 249 250 iterator(ctx, handler, value_buf, data_len); 251 next_dir_item: 252 cur += this_len; 253 di = (struct btrfs_dir_item *)((char *) di + this_len); 254 } 255 256 next_slot: 257 path->slots[0]++; 258 } 259 260 ret = 0; 261 out: 262 btrfs_release_path(path); 263 kfree(name_buf); 264 kfree(value_buf); 265 266 return ret; 267 } 268 269 static void inode_prop_iterator(void *ctx, 270 const struct prop_handler *handler, 271 const char *value, 272 size_t len) 273 { 274 struct inode *inode = ctx; 275 struct btrfs_root *root = BTRFS_I(inode)->root; 276 int ret; 277 278 ret = handler->apply(inode, value, len); 279 if (unlikely(ret)) 280 btrfs_warn(root->fs_info, 281 "error applying prop %s to ino %llu (root %llu): %d", 282 handler->xattr_name, btrfs_ino(BTRFS_I(inode)), 283 root->root_key.objectid, ret); 284 else 285 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); 286 } 287 288 int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) 289 { 290 struct btrfs_root *root = BTRFS_I(inode)->root; 291 u64 ino = btrfs_ino(BTRFS_I(inode)); 292 int ret; 293 294 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode); 295 296 return ret; 297 } 298 299 static int inherit_props(struct btrfs_trans_handle *trans, 300 struct inode *inode, 301 struct inode *parent) 302 { 303 struct btrfs_root *root = BTRFS_I(inode)->root; 304 struct btrfs_fs_info *fs_info = root->fs_info; 305 int ret; 306 int i; 307 308 if (!test_bit(BTRFS_INODE_HAS_PROPS, 309 &BTRFS_I(parent)->runtime_flags)) 310 return 0; 311 312 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { 313 const struct prop_handler *h = &prop_handlers[i]; 314 const char *value; 315 u64 num_bytes; 316 317 if (!h->inheritable) 318 continue; 319 320 value = h->extract(parent); 321 if (!value) 322 continue; 323 324 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1); 325 ret = btrfs_block_rsv_add(root, trans->block_rsv, 326 num_bytes, BTRFS_RESERVE_NO_FLUSH); 327 if (ret) 328 goto out; 329 ret = __btrfs_set_prop(trans, inode, h->xattr_name, 330 value, strlen(value), 0); 331 btrfs_block_rsv_release(fs_info, trans->block_rsv, num_bytes); 332 if (ret) 333 goto out; 334 } 335 ret = 0; 336 out: 337 return ret; 338 } 339 340 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans, 341 struct inode *inode, 342 struct inode *dir) 343 { 344 if (!dir) 345 return 0; 346 347 return inherit_props(trans, inode, dir); 348 } 349 350 int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans, 351 struct btrfs_root *root, 352 struct btrfs_root *parent_root) 353 { 354 struct super_block *sb = root->fs_info->sb; 355 struct btrfs_key key; 356 struct inode *parent_inode, *child_inode; 357 int ret; 358 359 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 360 key.type = BTRFS_INODE_ITEM_KEY; 361 key.offset = 0; 362 363 parent_inode = btrfs_iget(sb, &key, parent_root, NULL); 364 if (IS_ERR(parent_inode)) 365 return PTR_ERR(parent_inode); 366 367 child_inode = btrfs_iget(sb, &key, root, NULL); 368 if (IS_ERR(child_inode)) { 369 iput(parent_inode); 370 return PTR_ERR(child_inode); 371 } 372 373 ret = inherit_props(trans, child_inode, parent_inode); 374 iput(child_inode); 375 iput(parent_inode); 376 377 return ret; 378 } 379 380 static int prop_compression_validate(const char *value, size_t len) 381 { 382 if (!strncmp("lzo", value, len)) 383 return 0; 384 else if (!strncmp("zlib", value, len)) 385 return 0; 386 387 return -EINVAL; 388 } 389 390 static int prop_compression_apply(struct inode *inode, 391 const char *value, 392 size_t len) 393 { 394 int type; 395 396 if (len == 0) { 397 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 398 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; 399 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; 400 401 return 0; 402 } 403 404 if (!strncmp("lzo", value, len)) 405 type = BTRFS_COMPRESS_LZO; 406 else if (!strncmp("zlib", value, len)) 407 type = BTRFS_COMPRESS_ZLIB; 408 else 409 return -EINVAL; 410 411 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; 412 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; 413 BTRFS_I(inode)->force_compress = type; 414 415 return 0; 416 } 417 418 static const char *prop_compression_extract(struct inode *inode) 419 { 420 switch (BTRFS_I(inode)->force_compress) { 421 case BTRFS_COMPRESS_ZLIB: 422 return "zlib"; 423 case BTRFS_COMPRESS_LZO: 424 return "lzo"; 425 } 426 427 return NULL; 428 } 429 430 431