1 /* 2 * linux/fs/hfsplus/extents.c 3 * 4 * Copyright (C) 2001 5 * Brad Boyer (flar@allandria.com) 6 * (C) 2003 Ardis Technologies <roman@ardistech.com> 7 * 8 * Handling of Extents both in catalog and extents overflow trees 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/fs.h> 13 #include <linux/pagemap.h> 14 15 #include "hfsplus_fs.h" 16 #include "hfsplus_raw.h" 17 18 /* Compare two extents keys, returns 0 on same, pos/neg for difference */ 19 int hfsplus_ext_cmp_key(hfsplus_btree_key *k1, hfsplus_btree_key *k2) 20 { 21 __be32 k1id, k2id; 22 __be32 k1s, k2s; 23 24 k1id = k1->ext.cnid; 25 k2id = k2->ext.cnid; 26 if (k1id != k2id) 27 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1; 28 29 if (k1->ext.fork_type != k2->ext.fork_type) 30 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1; 31 32 k1s = k1->ext.start_block; 33 k2s = k2->ext.start_block; 34 if (k1s == k2s) 35 return 0; 36 return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1; 37 } 38 39 static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid, 40 u32 block, u8 type) 41 { 42 key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2); 43 key->ext.cnid = cpu_to_be32(cnid); 44 key->ext.start_block = cpu_to_be32(block); 45 key->ext.fork_type = type; 46 key->ext.pad = 0; 47 } 48 49 static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off) 50 { 51 int i; 52 u32 count; 53 54 for (i = 0; i < 8; ext++, i++) { 55 count = be32_to_cpu(ext->block_count); 56 if (off < count) 57 return be32_to_cpu(ext->start_block) + off; 58 off -= count; 59 } 60 /* panic? */ 61 return 0; 62 } 63 64 static int hfsplus_ext_block_count(struct hfsplus_extent *ext) 65 { 66 int i; 67 u32 count = 0; 68 69 for (i = 0; i < 8; ext++, i++) 70 count += be32_to_cpu(ext->block_count); 71 return count; 72 } 73 74 static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext) 75 { 76 int i; 77 78 ext += 7; 79 for (i = 0; i < 7; ext--, i++) 80 if (ext->block_count) 81 break; 82 return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count); 83 } 84 85 static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd) 86 { 87 int res; 88 89 hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start, 90 HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); 91 res = hfs_brec_find(fd); 92 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) { 93 if (res != -ENOENT) 94 return; 95 hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec)); 96 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW); 97 } else { 98 if (res) 99 return; 100 hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength); 101 HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY; 102 } 103 } 104 105 void hfsplus_ext_write_extent(struct inode *inode) 106 { 107 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) { 108 struct hfs_find_data fd; 109 110 hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd); 111 __hfsplus_ext_write_extent(inode, &fd); 112 hfs_find_exit(&fd); 113 } 114 } 115 116 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd, 117 struct hfsplus_extent *extent, 118 u32 cnid, u32 block, u8 type) 119 { 120 int res; 121 122 hfsplus_ext_build_key(fd->search_key, cnid, block, type); 123 fd->key->ext.cnid = 0; 124 res = hfs_brec_find(fd); 125 if (res && res != -ENOENT) 126 return res; 127 if (fd->key->ext.cnid != fd->search_key->ext.cnid || 128 fd->key->ext.fork_type != fd->search_key->ext.fork_type) 129 return -ENOENT; 130 if (fd->entrylength != sizeof(hfsplus_extent_rec)) 131 return -EIO; 132 hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec)); 133 return 0; 134 } 135 136 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block) 137 { 138 int res; 139 140 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) 141 __hfsplus_ext_write_extent(inode, fd); 142 143 res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino, 144 block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); 145 if (!res) { 146 HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block); 147 HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents); 148 } else { 149 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0; 150 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW); 151 } 152 return res; 153 } 154 155 static int hfsplus_ext_read_extent(struct inode *inode, u32 block) 156 { 157 struct hfs_find_data fd; 158 int res; 159 160 if (block >= HFSPLUS_I(inode).cached_start && 161 block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks) 162 return 0; 163 164 hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd); 165 res = __hfsplus_ext_cache_extent(&fd, inode, block); 166 hfs_find_exit(&fd); 167 return res; 168 } 169 170 /* Get a block at iblock for inode, possibly allocating if create */ 171 int hfsplus_get_block(struct inode *inode, sector_t iblock, 172 struct buffer_head *bh_result, int create) 173 { 174 struct super_block *sb; 175 int res = -EIO; 176 u32 ablock, dblock, mask; 177 int shift; 178 179 sb = inode->i_sb; 180 181 /* Convert inode block to disk allocation block */ 182 shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits; 183 ablock = iblock >> HFSPLUS_SB(sb).fs_shift; 184 185 if (iblock >= HFSPLUS_I(inode).fs_blocks) { 186 if (iblock > HFSPLUS_I(inode).fs_blocks || !create) 187 return -EIO; 188 if (ablock >= HFSPLUS_I(inode).alloc_blocks) { 189 res = hfsplus_file_extend(inode); 190 if (res) 191 return res; 192 } 193 } else 194 create = 0; 195 196 if (ablock < HFSPLUS_I(inode).first_blocks) { 197 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock); 198 goto done; 199 } 200 201 down(&HFSPLUS_I(inode).extents_lock); 202 res = hfsplus_ext_read_extent(inode, ablock); 203 if (!res) { 204 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock - 205 HFSPLUS_I(inode).cached_start); 206 } else { 207 up(&HFSPLUS_I(inode).extents_lock); 208 return -EIO; 209 } 210 up(&HFSPLUS_I(inode).extents_lock); 211 212 done: 213 dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock); 214 mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1; 215 map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask)); 216 if (create) { 217 set_buffer_new(bh_result); 218 HFSPLUS_I(inode).phys_size += sb->s_blocksize; 219 HFSPLUS_I(inode).fs_blocks++; 220 inode_add_bytes(inode, sb->s_blocksize); 221 mark_inode_dirty(inode); 222 } 223 return 0; 224 } 225 226 static void hfsplus_dump_extent(struct hfsplus_extent *extent) 227 { 228 int i; 229 230 dprint(DBG_EXTENT, " "); 231 for (i = 0; i < 8; i++) 232 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block), 233 be32_to_cpu(extent[i].block_count)); 234 dprint(DBG_EXTENT, "\n"); 235 } 236 237 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset, 238 u32 alloc_block, u32 block_count) 239 { 240 u32 count, start; 241 int i; 242 243 hfsplus_dump_extent(extent); 244 for (i = 0; i < 8; extent++, i++) { 245 count = be32_to_cpu(extent->block_count); 246 if (offset == count) { 247 start = be32_to_cpu(extent->start_block); 248 if (alloc_block != start + count) { 249 if (++i >= 8) 250 return -ENOSPC; 251 extent++; 252 extent->start_block = cpu_to_be32(alloc_block); 253 } else 254 block_count += count; 255 extent->block_count = cpu_to_be32(block_count); 256 return 0; 257 } else if (offset < count) 258 break; 259 offset -= count; 260 } 261 /* panic? */ 262 return -EIO; 263 } 264 265 static int hfsplus_free_extents(struct super_block *sb, 266 struct hfsplus_extent *extent, 267 u32 offset, u32 block_nr) 268 { 269 u32 count, start; 270 int i; 271 272 hfsplus_dump_extent(extent); 273 for (i = 0; i < 8; extent++, i++) { 274 count = be32_to_cpu(extent->block_count); 275 if (offset == count) 276 goto found; 277 else if (offset < count) 278 break; 279 offset -= count; 280 } 281 /* panic? */ 282 return -EIO; 283 found: 284 for (;;) { 285 start = be32_to_cpu(extent->start_block); 286 if (count <= block_nr) { 287 hfsplus_block_free(sb, start, count); 288 extent->block_count = 0; 289 extent->start_block = 0; 290 block_nr -= count; 291 } else { 292 count -= block_nr; 293 hfsplus_block_free(sb, start + count, block_nr); 294 extent->block_count = cpu_to_be32(count); 295 block_nr = 0; 296 } 297 if (!block_nr || !i) 298 return 0; 299 i--; 300 extent--; 301 count = be32_to_cpu(extent->block_count); 302 } 303 } 304 305 int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type) 306 { 307 struct hfs_find_data fd; 308 hfsplus_extent_rec ext_entry; 309 u32 total_blocks, blocks, start; 310 int res, i; 311 312 total_blocks = be32_to_cpu(fork->total_blocks); 313 if (!total_blocks) 314 return 0; 315 316 blocks = 0; 317 for (i = 0; i < 8; i++) 318 blocks += be32_to_cpu(fork->extents[i].block_count); 319 320 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks); 321 if (res) 322 return res; 323 if (total_blocks == blocks) 324 return 0; 325 326 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd); 327 do { 328 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid, 329 total_blocks, type); 330 if (res) 331 break; 332 start = be32_to_cpu(fd.key->ext.start_block); 333 hfsplus_free_extents(sb, ext_entry, 334 total_blocks - start, 335 total_blocks); 336 hfs_brec_remove(&fd); 337 total_blocks = start; 338 } while (total_blocks > blocks); 339 hfs_find_exit(&fd); 340 341 return res; 342 } 343 344 int hfsplus_file_extend(struct inode *inode) 345 { 346 struct super_block *sb = inode->i_sb; 347 u32 start, len, goal; 348 int res; 349 350 if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) { 351 // extend alloc file 352 printk("extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8, 353 HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks); 354 return -ENOSPC; 355 //BUG(); 356 } 357 358 down(&HFSPLUS_I(inode).extents_lock); 359 if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks) 360 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents); 361 else { 362 res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks); 363 if (res) 364 goto out; 365 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents); 366 } 367 368 len = HFSPLUS_I(inode).clump_blocks; 369 start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len); 370 if (start >= HFSPLUS_SB(sb).total_blocks) { 371 start = hfsplus_block_allocate(sb, goal, 0, &len); 372 if (start >= goal) { 373 res = -ENOSPC; 374 goto out; 375 } 376 } 377 378 dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len); 379 if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) { 380 if (!HFSPLUS_I(inode).first_blocks) { 381 dprint(DBG_EXTENT, "first extents\n"); 382 /* no extents yet */ 383 HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start); 384 HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len); 385 res = 0; 386 } else { 387 /* try to append to extents in inode */ 388 res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents, 389 HFSPLUS_I(inode).alloc_blocks, 390 start, len); 391 if (res == -ENOSPC) 392 goto insert_extent; 393 } 394 if (!res) { 395 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents); 396 HFSPLUS_I(inode).first_blocks += len; 397 } 398 } else { 399 res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents, 400 HFSPLUS_I(inode).alloc_blocks - 401 HFSPLUS_I(inode).cached_start, 402 start, len); 403 if (!res) { 404 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents); 405 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY; 406 HFSPLUS_I(inode).cached_blocks += len; 407 } else if (res == -ENOSPC) 408 goto insert_extent; 409 } 410 out: 411 up(&HFSPLUS_I(inode).extents_lock); 412 if (!res) { 413 HFSPLUS_I(inode).alloc_blocks += len; 414 mark_inode_dirty(inode); 415 } 416 return res; 417 418 insert_extent: 419 dprint(DBG_EXTENT, "insert new extent\n"); 420 hfsplus_ext_write_extent(inode); 421 422 memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec)); 423 HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start); 424 HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len); 425 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents); 426 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW; 427 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks; 428 HFSPLUS_I(inode).cached_blocks = len; 429 430 res = 0; 431 goto out; 432 } 433 434 void hfsplus_file_truncate(struct inode *inode) 435 { 436 struct super_block *sb = inode->i_sb; 437 struct hfs_find_data fd; 438 u32 alloc_cnt, blk_cnt, start; 439 int res; 440 441 dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino, 442 (long long)HFSPLUS_I(inode).phys_size, inode->i_size); 443 if (inode->i_size > HFSPLUS_I(inode).phys_size) { 444 struct address_space *mapping = inode->i_mapping; 445 struct page *page; 446 u32 size = inode->i_size - 1; 447 int res; 448 449 page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT); 450 if (!page) 451 return; 452 size &= PAGE_CACHE_SIZE - 1; 453 size++; 454 res = mapping->a_ops->prepare_write(NULL, page, size, size); 455 if (!res) 456 res = mapping->a_ops->commit_write(NULL, page, size, size); 457 if (res) 458 inode->i_size = HFSPLUS_I(inode).phys_size; 459 unlock_page(page); 460 page_cache_release(page); 461 mark_inode_dirty(inode); 462 return; 463 } else if (inode->i_size == HFSPLUS_I(inode).phys_size) 464 return; 465 466 blk_cnt = (inode->i_size + HFSPLUS_SB(sb).alloc_blksz - 1) >> HFSPLUS_SB(sb).alloc_blksz_shift; 467 alloc_cnt = HFSPLUS_I(inode).alloc_blocks; 468 if (blk_cnt == alloc_cnt) 469 goto out; 470 471 down(&HFSPLUS_I(inode).extents_lock); 472 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd); 473 while (1) { 474 if (alloc_cnt == HFSPLUS_I(inode).first_blocks) { 475 hfsplus_free_extents(sb, HFSPLUS_I(inode).first_extents, 476 alloc_cnt, alloc_cnt - blk_cnt); 477 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents); 478 HFSPLUS_I(inode).first_blocks = blk_cnt; 479 break; 480 } 481 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt); 482 if (res) 483 break; 484 start = HFSPLUS_I(inode).cached_start; 485 hfsplus_free_extents(sb, HFSPLUS_I(inode).cached_extents, 486 alloc_cnt - start, alloc_cnt - blk_cnt); 487 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents); 488 if (blk_cnt > start) { 489 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY; 490 break; 491 } 492 alloc_cnt = start; 493 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0; 494 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW); 495 hfs_brec_remove(&fd); 496 } 497 hfs_find_exit(&fd); 498 up(&HFSPLUS_I(inode).extents_lock); 499 500 HFSPLUS_I(inode).alloc_blocks = blk_cnt; 501 out: 502 HFSPLUS_I(inode).phys_size = inode->i_size; 503 HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 504 inode_set_bytes(inode, HFSPLUS_I(inode).fs_blocks << sb->s_blocksize_bits); 505 mark_inode_dirty(inode); 506 } 507