1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/hfsplus/attributes.c 4 * 5 * Vyacheslav Dubeyko <slava@dubeyko.com> 6 * 7 * Handling of records in attributes tree 8 */ 9 10 #include "hfsplus_fs.h" 11 #include "hfsplus_raw.h" 12 13 static struct kmem_cache *hfsplus_attr_tree_cachep; 14 15 int __init hfsplus_create_attr_tree_cache(void) 16 { 17 if (hfsplus_attr_tree_cachep) 18 return -EEXIST; 19 20 hfsplus_attr_tree_cachep = 21 kmem_cache_create("hfsplus_attr_cache", 22 sizeof(hfsplus_attr_entry), 0, 23 SLAB_HWCACHE_ALIGN, NULL); 24 if (!hfsplus_attr_tree_cachep) 25 return -ENOMEM; 26 27 return 0; 28 } 29 30 void hfsplus_destroy_attr_tree_cache(void) 31 { 32 kmem_cache_destroy(hfsplus_attr_tree_cachep); 33 } 34 35 int hfsplus_attr_bin_cmp_key(const hfsplus_btree_key *k1, 36 const hfsplus_btree_key *k2) 37 { 38 __be32 k1_cnid, k2_cnid; 39 40 k1_cnid = k1->attr.cnid; 41 k2_cnid = k2->attr.cnid; 42 if (k1_cnid != k2_cnid) 43 return be32_to_cpu(k1_cnid) < be32_to_cpu(k2_cnid) ? -1 : 1; 44 45 return hfsplus_strcmp( 46 (const struct hfsplus_unistr *)&k1->attr.key_name, 47 (const struct hfsplus_unistr *)&k2->attr.key_name); 48 } 49 50 int hfsplus_attr_build_key(struct super_block *sb, hfsplus_btree_key *key, 51 u32 cnid, const char *name) 52 { 53 int len; 54 55 memset(key, 0, sizeof(struct hfsplus_attr_key)); 56 key->attr.cnid = cpu_to_be32(cnid); 57 if (name) { 58 int res = hfsplus_asc2uni(sb, 59 (struct hfsplus_unistr *)&key->attr.key_name, 60 HFSPLUS_ATTR_MAX_STRLEN, name, strlen(name)); 61 if (res) 62 return res; 63 len = be16_to_cpu(key->attr.key_name.length); 64 } else { 65 key->attr.key_name.length = 0; 66 len = 0; 67 } 68 69 /* The length of the key, as stored in key_len field, does not include 70 * the size of the key_len field itself. 71 * So, offsetof(hfsplus_attr_key, key_name) is a trick because 72 * it takes into consideration key_len field (__be16) of 73 * hfsplus_attr_key structure instead of length field (__be16) of 74 * hfsplus_attr_unistr structure. 75 */ 76 key->key_len = 77 cpu_to_be16(offsetof(struct hfsplus_attr_key, key_name) + 78 2 * len); 79 80 return 0; 81 } 82 83 hfsplus_attr_entry *hfsplus_alloc_attr_entry(void) 84 { 85 return kmem_cache_alloc(hfsplus_attr_tree_cachep, GFP_KERNEL); 86 } 87 88 void hfsplus_destroy_attr_entry(hfsplus_attr_entry *entry) 89 { 90 if (entry) 91 kmem_cache_free(hfsplus_attr_tree_cachep, entry); 92 } 93 94 #define HFSPLUS_INVALID_ATTR_RECORD -1 95 96 static int hfsplus_attr_build_record(hfsplus_attr_entry *entry, int record_type, 97 u32 cnid, const void *value, size_t size) 98 { 99 if (record_type == HFSPLUS_ATTR_FORK_DATA) { 100 /* 101 * Mac OS X supports only inline data attributes. 102 * Do nothing 103 */ 104 memset(entry, 0, sizeof(*entry)); 105 return sizeof(struct hfsplus_attr_fork_data); 106 } else if (record_type == HFSPLUS_ATTR_EXTENTS) { 107 /* 108 * Mac OS X supports only inline data attributes. 109 * Do nothing. 110 */ 111 memset(entry, 0, sizeof(*entry)); 112 return sizeof(struct hfsplus_attr_extents); 113 } else if (record_type == HFSPLUS_ATTR_INLINE_DATA) { 114 u16 len; 115 116 memset(entry, 0, sizeof(struct hfsplus_attr_inline_data)); 117 entry->inline_data.record_type = cpu_to_be32(record_type); 118 if (size <= HFSPLUS_MAX_INLINE_DATA_SIZE) 119 len = size; 120 else 121 return HFSPLUS_INVALID_ATTR_RECORD; 122 entry->inline_data.length = cpu_to_be16(len); 123 memcpy(entry->inline_data.raw_bytes, value, len); 124 /* 125 * Align len on two-byte boundary. 126 * It needs to add pad byte if we have odd len. 127 */ 128 len = round_up(len, 2); 129 return offsetof(struct hfsplus_attr_inline_data, raw_bytes) + 130 len; 131 } else /* invalid input */ 132 memset(entry, 0, sizeof(*entry)); 133 134 return HFSPLUS_INVALID_ATTR_RECORD; 135 } 136 137 int hfsplus_find_attr(struct super_block *sb, u32 cnid, 138 const char *name, struct hfs_find_data *fd) 139 { 140 int err = 0; 141 142 hfs_dbg(ATTR_MOD, "find_attr: %s,%d\n", name ? name : NULL, cnid); 143 144 if (!HFSPLUS_SB(sb)->attr_tree) { 145 pr_err("attributes file doesn't exist\n"); 146 return -EINVAL; 147 } 148 149 if (name) { 150 err = hfsplus_attr_build_key(sb, fd->search_key, cnid, name); 151 if (err) 152 goto failed_find_attr; 153 err = hfs_brec_find(fd, hfs_find_rec_by_key); 154 if (err) 155 goto failed_find_attr; 156 } else { 157 err = hfsplus_attr_build_key(sb, fd->search_key, cnid, NULL); 158 if (err) 159 goto failed_find_attr; 160 err = hfs_brec_find(fd, hfs_find_1st_rec_by_cnid); 161 if (err) 162 goto failed_find_attr; 163 } 164 165 failed_find_attr: 166 return err; 167 } 168 169 int hfsplus_attr_exists(struct inode *inode, const char *name) 170 { 171 int err = 0; 172 struct super_block *sb = inode->i_sb; 173 struct hfs_find_data fd; 174 175 if (!HFSPLUS_SB(sb)->attr_tree) 176 return 0; 177 178 err = hfs_find_init(HFSPLUS_SB(sb)->attr_tree, &fd); 179 if (err) 180 return 0; 181 182 err = hfsplus_find_attr(sb, inode->i_ino, name, &fd); 183 if (err) 184 goto attr_not_found; 185 186 hfs_find_exit(&fd); 187 return 1; 188 189 attr_not_found: 190 hfs_find_exit(&fd); 191 return 0; 192 } 193 194 int hfsplus_create_attr(struct inode *inode, 195 const char *name, 196 const void *value, size_t size) 197 { 198 struct super_block *sb = inode->i_sb; 199 struct hfs_find_data fd; 200 hfsplus_attr_entry *entry_ptr; 201 int entry_size; 202 int err; 203 204 hfs_dbg(ATTR_MOD, "create_attr: %s,%ld\n", 205 name ? name : NULL, inode->i_ino); 206 207 if (!HFSPLUS_SB(sb)->attr_tree) { 208 pr_err("attributes file doesn't exist\n"); 209 return -EINVAL; 210 } 211 212 entry_ptr = hfsplus_alloc_attr_entry(); 213 if (!entry_ptr) 214 return -ENOMEM; 215 216 err = hfs_find_init(HFSPLUS_SB(sb)->attr_tree, &fd); 217 if (err) 218 goto failed_init_create_attr; 219 220 /* Fail early and avoid ENOSPC during the btree operation */ 221 err = hfs_bmap_reserve(fd.tree, fd.tree->depth + 1); 222 if (err) 223 goto failed_create_attr; 224 225 if (name) { 226 err = hfsplus_attr_build_key(sb, fd.search_key, 227 inode->i_ino, name); 228 if (err) 229 goto failed_create_attr; 230 } else { 231 err = -EINVAL; 232 goto failed_create_attr; 233 } 234 235 /* Mac OS X supports only inline data attributes. */ 236 entry_size = hfsplus_attr_build_record(entry_ptr, 237 HFSPLUS_ATTR_INLINE_DATA, 238 inode->i_ino, 239 value, size); 240 if (entry_size == HFSPLUS_INVALID_ATTR_RECORD) { 241 err = -EINVAL; 242 goto failed_create_attr; 243 } 244 245 err = hfs_brec_find(&fd, hfs_find_rec_by_key); 246 if (err != -ENOENT) { 247 if (!err) 248 err = -EEXIST; 249 goto failed_create_attr; 250 } 251 252 err = hfs_brec_insert(&fd, entry_ptr, entry_size); 253 if (err) 254 goto failed_create_attr; 255 256 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ATTR_DIRTY); 257 258 failed_create_attr: 259 hfs_find_exit(&fd); 260 261 failed_init_create_attr: 262 hfsplus_destroy_attr_entry(entry_ptr); 263 return err; 264 } 265 266 static int __hfsplus_delete_attr(struct inode *inode, u32 cnid, 267 struct hfs_find_data *fd) 268 { 269 int err = 0; 270 __be32 found_cnid, record_type; 271 272 hfs_bnode_read(fd->bnode, &found_cnid, 273 fd->keyoffset + 274 offsetof(struct hfsplus_attr_key, cnid), 275 sizeof(__be32)); 276 if (cnid != be32_to_cpu(found_cnid)) 277 return -ENOENT; 278 279 hfs_bnode_read(fd->bnode, &record_type, 280 fd->entryoffset, sizeof(record_type)); 281 282 switch (be32_to_cpu(record_type)) { 283 case HFSPLUS_ATTR_INLINE_DATA: 284 /* All is OK. Do nothing. */ 285 break; 286 case HFSPLUS_ATTR_FORK_DATA: 287 case HFSPLUS_ATTR_EXTENTS: 288 pr_err("only inline data xattr are supported\n"); 289 return -EOPNOTSUPP; 290 default: 291 pr_err("invalid extended attribute record\n"); 292 return -ENOENT; 293 } 294 295 /* Avoid btree corruption */ 296 hfs_bnode_read(fd->bnode, fd->search_key, 297 fd->keyoffset, fd->keylength); 298 299 err = hfs_brec_remove(fd); 300 if (err) 301 return err; 302 303 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ATTR_DIRTY); 304 return err; 305 } 306 307 int hfsplus_delete_attr(struct inode *inode, const char *name) 308 { 309 int err = 0; 310 struct super_block *sb = inode->i_sb; 311 struct hfs_find_data fd; 312 313 hfs_dbg(ATTR_MOD, "delete_attr: %s,%ld\n", 314 name ? name : NULL, inode->i_ino); 315 316 if (!HFSPLUS_SB(sb)->attr_tree) { 317 pr_err("attributes file doesn't exist\n"); 318 return -EINVAL; 319 } 320 321 err = hfs_find_init(HFSPLUS_SB(sb)->attr_tree, &fd); 322 if (err) 323 return err; 324 325 /* Fail early and avoid ENOSPC during the btree operation */ 326 err = hfs_bmap_reserve(fd.tree, fd.tree->depth); 327 if (err) 328 goto out; 329 330 if (name) { 331 err = hfsplus_attr_build_key(sb, fd.search_key, 332 inode->i_ino, name); 333 if (err) 334 goto out; 335 } else { 336 pr_err("invalid extended attribute name\n"); 337 err = -EINVAL; 338 goto out; 339 } 340 341 err = hfs_brec_find(&fd, hfs_find_rec_by_key); 342 if (err) 343 goto out; 344 345 err = __hfsplus_delete_attr(inode, inode->i_ino, &fd); 346 if (err) 347 goto out; 348 349 out: 350 hfs_find_exit(&fd); 351 return err; 352 } 353 354 int hfsplus_delete_all_attrs(struct inode *dir, u32 cnid) 355 { 356 int err = 0; 357 struct hfs_find_data fd; 358 359 hfs_dbg(ATTR_MOD, "delete_all_attrs: %d\n", cnid); 360 361 if (!HFSPLUS_SB(dir->i_sb)->attr_tree) { 362 pr_err("attributes file doesn't exist\n"); 363 return -EINVAL; 364 } 365 366 err = hfs_find_init(HFSPLUS_SB(dir->i_sb)->attr_tree, &fd); 367 if (err) 368 return err; 369 370 for (;;) { 371 err = hfsplus_find_attr(dir->i_sb, cnid, NULL, &fd); 372 if (err) { 373 if (err != -ENOENT) 374 pr_err("xattr search failed\n"); 375 goto end_delete_all; 376 } 377 378 err = __hfsplus_delete_attr(dir, cnid, &fd); 379 if (err) 380 goto end_delete_all; 381 } 382 383 end_delete_all: 384 hfs_find_exit(&fd); 385 return err; 386 } 387