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 */ 19int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1, 20 const hfsplus_btree_key *k2) 21{ 22 __be32 k1id, k2id; 23 __be32 k1s, k2s; 24 25 k1id = k1->ext.cnid; 26 k2id = k2->ext.cnid; 27 if (k1id != k2id) 28 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1; 29 30 if (k1->ext.fork_type != k2->ext.fork_type) 31 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1; 32 33 k1s = k1->ext.start_block; 34 k2s = k2->ext.start_block; 35 if (k1s == k2s) 36 return 0; 37 return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1; 38} 39 40static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid, 41 u32 block, u8 type) 42{ 43 key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2); 44 key->ext.cnid = cpu_to_be32(cnid); 45 key->ext.start_block = cpu_to_be32(block); 46 key->ext.fork_type = type; 47 key->ext.pad = 0; 48} 49 50static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off) 51{ 52 int i; 53 u32 count; 54 55 for (i = 0; i < 8; ext++, i++) { 56 count = be32_to_cpu(ext->block_count); 57 if (off < count) 58 return be32_to_cpu(ext->start_block) + off; 59 off -= count; 60 } 61 /* panic? */ 62 return 0; 63} 64 65static int hfsplus_ext_block_count(struct hfsplus_extent *ext) 66{ 67 int i; 68 u32 count = 0; 69 70 for (i = 0; i < 8; ext++, i++) 71 count += be32_to_cpu(ext->block_count); 72 return count; 73} 74 75static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext) 76{ 77 int i; 78 79 ext += 7; 80 for (i = 0; i < 7; ext--, i++) 81 if (ext->block_count) 82 break; 83 return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count); 84} 85 86static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd) 87{ 88 int res; 89 90 hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start, 91 HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); 92 res = hfs_brec_find(fd); 93 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) { 94 if (res != -ENOENT) 95 return; 96 hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec)); 97 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW); 98 } else { 99 if (res) 100 return; 101 hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength); 102 HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY; 103 } 104} 105 106void hfsplus_ext_write_extent(struct inode *inode) 107{ 108 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) { 109 struct hfs_find_data fd; 110 111 hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd); 112 __hfsplus_ext_write_extent(inode, &fd); 113 hfs_find_exit(&fd); 114 } 115} 116 117static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd, 118 struct hfsplus_extent *extent, 119 u32 cnid, u32 block, u8 type) 120{ 121 int res; 122 123 hfsplus_ext_build_key(fd->search_key, cnid, block, type); 124 fd->key->ext.cnid = 0; 125 res = hfs_brec_find(fd); 126 if (res && res != -ENOENT) 127 return res; 128 if (fd->key->ext.cnid != fd->search_key->ext.cnid || 129 fd->key->ext.fork_type != fd->search_key->ext.fork_type) 130 return -ENOENT; 131 if (fd->entrylength != sizeof(hfsplus_extent_rec)) 132 return -EIO; 133 hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec)); 134 return 0; 135} 136 137static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block) 138{ 139 int res; 140 141 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) 142 __hfsplus_ext_write_extent(inode, fd); 143 144 res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino, 145 block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); 146 if (!res) { 147 HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block); 148 HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents); 149 } else { 150 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0; 151 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW); 152 } 153 return res; 154} 155 156static int hfsplus_ext_read_extent(struct inode *inode, u32 block) 157{ 158 struct hfs_find_data fd; 159 int res; 160 161 if (block >= HFSPLUS_I(inode).cached_start && 162 block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks) 163 return 0; 164 165 hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd); 166 res = __hfsplus_ext_cache_extent(&fd, inode, block); 167 hfs_find_exit(&fd); 168 return res; 169} 170 171/* Get a block at iblock for inode, possibly allocating if create */ 172int hfsplus_get_block(struct inode *inode, sector_t iblock, 173 struct buffer_head *bh_result, int create) 174{ 175 struct super_block *sb; 176 int res = -EIO; 177 u32 ablock, dblock, mask; 178 int shift; 179 180 sb = inode->i_sb; 181 182 /* Convert inode block to disk allocation block */ 183 shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits; 184 ablock = iblock >> HFSPLUS_SB(sb).fs_shift; 185 186 if (iblock >= HFSPLUS_I(inode).fs_blocks) { 187 if (iblock > HFSPLUS_I(inode).fs_blocks || !create) 188 return -EIO; 189 if (ablock >= HFSPLUS_I(inode).alloc_blocks) { 190 res = hfsplus_file_extend(inode); 191 if (res) 192 return res; 193 } 194 } else 195 create = 0; 196 197 if (ablock < HFSPLUS_I(inode).first_blocks) { 198 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock); 199 goto done; 200 } 201 202 down(&HFSPLUS_I(inode).extents_lock); 203 res = hfsplus_ext_read_extent(inode, ablock); 204 if (!res) { 205 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock - 206 HFSPLUS_I(inode).cached_start); 207 } else { 208 up(&HFSPLUS_I(inode).extents_lock); 209 return -EIO; 210 } 211 up(&HFSPLUS_I(inode).extents_lock); 212 213done: 214 dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock); 215 mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1; 216 map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask)); 217 if (create) { 218 set_buffer_new(bh_result); 219 HFSPLUS_I(inode).phys_size += sb->s_blocksize; 220 HFSPLUS_I(inode).fs_blocks++; 221 inode_add_bytes(inode, sb->s_blocksize); 222 mark_inode_dirty(inode); 223 } 224 return 0; 225} 226 227static void hfsplus_dump_extent(struct hfsplus_extent *extent) 228{ 229 int i; 230 231 dprint(DBG_EXTENT, " "); 232 for (i = 0; i < 8; i++) 233 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block), 234 be32_to_cpu(extent[i].block_count)); 235 dprint(DBG_EXTENT, "\n"); 236} 237 238static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset, 239 u32 alloc_block, u32 block_count) 240{ 241 u32 count, start; 242 int i; 243 244 hfsplus_dump_extent(extent); 245 for (i = 0; i < 8; extent++, i++) { 246 count = be32_to_cpu(extent->block_count); 247 if (offset == count) { 248 start = be32_to_cpu(extent->start_block); 249 if (alloc_block != start + count) { 250 if (++i >= 8) 251 return -ENOSPC; 252 extent++; 253 extent->start_block = cpu_to_be32(alloc_block); 254 } else 255 block_count += count; 256 extent->block_count = cpu_to_be32(block_count); 257 return 0; 258 } else if (offset < count) 259 break; 260 offset -= count; 261 } 262 /* panic? */ 263 return -EIO; 264} 265 266static int hfsplus_free_extents(struct super_block *sb, 267 struct hfsplus_extent *extent, 268 u32 offset, u32 block_nr) 269{ 270 u32 count, start; 271 int i; 272 273 hfsplus_dump_extent(extent); 274 for (i = 0; i < 8; extent++, i++) { 275 count = be32_to_cpu(extent->block_count); 276 if (offset == count) 277 goto found; 278 else if (offset < count) 279 break; 280 offset -= count; 281 } 282 /* panic? */ 283 return -EIO; 284found: 285 for (;;) { 286 start = be32_to_cpu(extent->start_block); 287 if (count <= block_nr) { 288 hfsplus_block_free(sb, start, count); 289 extent->block_count = 0; 290 extent->start_block = 0; 291 block_nr -= count; 292 } else { 293 count -= block_nr; 294 hfsplus_block_free(sb, start + count, block_nr); 295 extent->block_count = cpu_to_be32(count); 296 block_nr = 0; 297 } 298 if (!block_nr || !i) 299 return 0; 300 i--; 301 extent--; 302 count = be32_to_cpu(extent->block_count); 303 } 304} 305 306int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type) 307{ 308 struct hfs_find_data fd; 309 hfsplus_extent_rec ext_entry; 310 u32 total_blocks, blocks, start; 311 int res, i; 312 313 total_blocks = be32_to_cpu(fork->total_blocks); 314 if (!total_blocks) 315 return 0; 316 317 blocks = 0; 318 for (i = 0; i < 8; i++) 319 blocks += be32_to_cpu(fork->extents[i].block_count); 320 321 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks); 322 if (res) 323 return res; 324 if (total_blocks == blocks) 325 return 0; 326 327 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd); 328 do { 329 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid, 330 total_blocks, type); 331 if (res) 332 break; 333 start = be32_to_cpu(fd.key->ext.start_block); 334 hfsplus_free_extents(sb, ext_entry, 335 total_blocks - start, 336 total_blocks); 337 hfs_brec_remove(&fd); 338 total_blocks = start; 339 } while (total_blocks > blocks); 340 hfs_find_exit(&fd); 341 342 return res; 343} 344 345int hfsplus_file_extend(struct inode *inode) 346{ 347 struct super_block *sb = inode->i_sb; 348 u32 start, len, goal; 349 int res; 350 351 if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) { 352 // extend alloc file 353 printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8, 354 HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks); 355 return -ENOSPC; 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 } 410out: 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 418insert_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 434void 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; 501out: 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 /* Foxconn added start pling 05/31/2010 */ 506 /* Set the i_blocks field properly */ 507 inode->i_blocks = inode->i_size/512; 508 if (inode->i_size % 512) 509 inode->i_blocks++; 510 /* Foxconn added end pling 05/31/2010 */ 511 mark_inode_dirty(inode); 512} 513