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sys/fs/ntfs/lcnalloc.c
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1 /* 2 * lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project. 3 * 4 * Copyright (c) 2004-2005 Anton Altaparmakov 5 * 6 * This program/include file is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as published 8 * by the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program/include file is distributed in the hope that it will be 12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program (in the main directory of the Linux-NTFS 18 * distribution in the file COPYING); if not, write to the Free Software 19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #ifdef NTFS_RW 23 24 #include <linux/pagemap.h> 25 26 #include "lcnalloc.h" 27 #include "debug.h" 28 #include "bitmap.h" 29 #include "inode.h" 30 #include "volume.h" 31 #include "attrib.h" 32 #include "malloc.h" 33 #include "aops.h" 34 #include "ntfs.h" 35 36 /** 37 * ntfs_cluster_free_from_rl_nolock - free clusters from runlist 38 * @vol: mounted ntfs volume on which to free the clusters 39 * @rl: runlist describing the clusters to free 40 * 41 * Free all the clusters described by the runlist @rl on the volume @vol. In 42 * the case of an error being returned, at least some of the clusters were not 43 * freed. 44 * 45 * Return 0 on success and -errno on error. 46 * 47 * Locking: - The volume lcn bitmap must be locked for writing on entry and is 48 * left locked on return. 49 */ 50 int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol, 51 const runlist_element *rl) 52 { 53 struct inode *lcnbmp_vi = vol->lcnbmp_ino; 54 int ret = 0; 55 56 ntfs_debug("Entering."); 57 if (!rl) 58 return 0; 59 for (; rl->length; rl++) { 60 int err; 61 62 if (rl->lcn < 0) 63 continue; 64 err = ntfs_bitmap_clear_run(lcnbmp_vi, rl->lcn, rl->length); 65 if (unlikely(err && (!ret || ret == -ENOMEM) && ret != err)) 66 ret = err; 67 } 68 ntfs_debug("Done."); 69 return ret; 70 } 71 72 /** 73 * ntfs_cluster_alloc - allocate clusters on an ntfs volume 74 * @vol: mounted ntfs volume on which to allocate the clusters 75 * @start_vcn: vcn to use for the first allocated cluster 76 * @count: number of clusters to allocate 77 * @start_lcn: starting lcn at which to allocate the clusters (or -1 if none) 78 * @zone: zone from which to allocate the clusters 79 * @is_extension: if 'true', this is an attribute extension 80 * 81 * Allocate @count clusters preferably starting at cluster @start_lcn or at the 82 * current allocator position if @start_lcn is -1, on the mounted ntfs volume 83 * @vol. @zone is either DATA_ZONE for allocation of normal clusters or 84 * MFT_ZONE for allocation of clusters for the master file table, i.e. the 85 * $MFT/$DATA attribute. 86 * 87 * @start_vcn specifies the vcn of the first allocated cluster. This makes 88 * merging the resulting runlist with the old runlist easier. 89 * 90 * If @is_extension is 'true', the caller is allocating clusters to extend an 91 * attribute and if it is 'false', the caller is allocating clusters to fill a 92 * hole in an attribute. Practically the difference is that if @is_extension 93 * is 'true' the returned runlist will be terminated with LCN_ENOENT and if 94 * @is_extension is 'false' the runlist will be terminated with 95 * LCN_RL_NOT_MAPPED. 96 * 97 * You need to check the return value with IS_ERR(). If this is false, the 98 * function was successful and the return value is a runlist describing the 99 * allocated cluster(s). If IS_ERR() is true, the function failed and 100 * PTR_ERR() gives you the error code. 101 * 102 * Notes on the allocation algorithm 103 * ================================= 104 * 105 * There are two data zones. First is the area between the end of the mft zone 106 * and the end of the volume, and second is the area between the start of the 107 * volume and the start of the mft zone. On unmodified/standard NTFS 1.x 108 * volumes, the second data zone does not exist due to the mft zone being 109 * expanded to cover the start of the volume in order to reserve space for the 110 * mft bitmap attribute. 111 * 112 * This is not the prettiest function but the complexity stems from the need of 113 * implementing the mft vs data zoned approach and from the fact that we have 114 * access to the lcn bitmap in portions of up to 8192 bytes at a time, so we 115 * need to cope with crossing over boundaries of two buffers. Further, the 116 * fact that the allocator allows for caller supplied hints as to the location 117 * of where allocation should begin and the fact that the allocator keeps track 118 * of where in the data zones the next natural allocation should occur, 119 * contribute to the complexity of the function. But it should all be 120 * worthwhile, because this allocator should: 1) be a full implementation of 121 * the MFT zone approach used by Windows NT, 2) cause reduction in 122 * fragmentation, and 3) be speedy in allocations (the code is not optimized 123 * for speed, but the algorithm is, so further speed improvements are probably 124 * possible). 125 * 126 * FIXME: We should be monitoring cluster allocation and increment the MFT zone 127 * size dynamically but this is something for the future. We will just cause 128 * heavier fragmentation by not doing it and I am not even sure Windows would 129 * grow the MFT zone dynamically, so it might even be correct not to do this. 130 * The overhead in doing dynamic MFT zone expansion would be very large and 131 * unlikely worth the effort. (AIA) 132 * 133 * TODO: I have added in double the required zone position pointer wrap around 134 * logic which can be optimized to having only one of the two logic sets. 135 * However, having the double logic will work fine, but if we have only one of 136 * the sets and we get it wrong somewhere, then we get into trouble, so 137 * removing the duplicate logic requires _very_ careful consideration of _all_ 138 * possible code paths. So at least for now, I am leaving the double logic - 139 * better safe than sorry... (AIA) 140 * 141 * Locking: - The volume lcn bitmap must be unlocked on entry and is unlocked 142 * on return. 143 * - This function takes the volume lcn bitmap lock for writing and 144 * modifies the bitmap contents. 145 */ 146 runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn, 147 const s64 count, const LCN start_lcn, 148 const NTFS_CLUSTER_ALLOCATION_ZONES zone, 149 const bool is_extension) 150 { 151 LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn; 152 LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size; 153 s64 clusters; 154 loff_t i_size; 155 struct inode *lcnbmp_vi; 156 runlist_element *rl = NULL; 157 struct address_space *mapping; 158 struct page *page = NULL; 159 u8 *buf, *byte; 160 int err = 0, rlpos, rlsize, buf_size; 161 u8 pass, done_zones, search_zone, need_writeback = 0, bit; 162 163 ntfs_debug("Entering for start_vcn 0x%llx, count 0x%llx, start_lcn " 164 "0x%llx, zone %s_ZONE.", (unsigned long long)start_vcn, 165 (unsigned long long)count, 166 (unsigned long long)start_lcn, 167 zone == MFT_ZONE ? "MFT" : "DATA"); 168 BUG_ON(!vol); 169 lcnbmp_vi = vol->lcnbmp_ino; 170 BUG_ON(!lcnbmp_vi); 171 BUG_ON(start_vcn < 0); 172 BUG_ON(count < 0); 173 BUG_ON(start_lcn < -1); 174 BUG_ON(zone < FIRST_ZONE); 175 BUG_ON(zone > LAST_ZONE); 176 177 /* Return NULL if @count is zero. */ 178 if (!count) 179 return NULL; 180 /* Take the lcnbmp lock for writing. */ 181 down_write(&vol->lcnbmp_lock); 182 /* 183 * If no specific @start_lcn was requested, use the current data zone 184 * position, otherwise use the requested @start_lcn but make sure it 185 * lies outside the mft zone. Also set done_zones to 0 (no zones done) 186 * and pass depending on whether we are starting inside a zone (1) or 187 * at the beginning of a zone (2). If requesting from the MFT_ZONE, 188 * we either start at the current position within the mft zone or at 189 * the specified position. If the latter is out of bounds then we start 190 * at the beginning of the MFT_ZONE. 191 */ 192 done_zones = 0; 193 pass = 1; 194 /* 195 * zone_start and zone_end are the current search range. search_zone 196 * is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of 197 * volume) and 4 for data zone 2 (start of volume till start of mft 198 * zone). 199 */ 200 zone_start = start_lcn; 201 if (zone_start < 0) { 202 if (zone == DATA_ZONE) 203 zone_start = vol->data1_zone_pos; 204 else 205 zone_start = vol->mft_zone_pos; 206 if (!zone_start) { 207 /* 208 * Zone starts at beginning of volume which means a 209 * single pass is sufficient. 210 */ 211 pass = 2; 212 } 213 } else if (zone == DATA_ZONE && zone_start >= vol->mft_zone_start && 214 zone_start < vol->mft_zone_end) { 215 zone_start = vol->mft_zone_end; 216 /* 217 * Starting at beginning of data1_zone which means a single 218 * pass in this zone is sufficient. 219 */ 220 pass = 2; 221 } else if (zone == MFT_ZONE && (zone_start < vol->mft_zone_start || 222 zone_start >= vol->mft_zone_end)) { 223 zone_start = vol->mft_lcn; 224 if (!vol->mft_zone_end) 225 zone_start = 0; 226 /* 227 * Starting at beginning of volume which means a single pass 228 * is sufficient. 229 */ 230 pass = 2; 231 } 232 if (zone == MFT_ZONE) { 233 zone_end = vol->mft_zone_end; 234 search_zone = 1; 235 } else /* if (zone == DATA_ZONE) */ { 236 /* Skip searching the mft zone. */ 237 done_zones |= 1; 238 if (zone_start >= vol->mft_zone_end) { 239 zone_end = vol->nr_clusters; 240 search_zone = 2; 241 } else { 242 zone_end = vol->mft_zone_start; 243 search_zone = 4; 244 } 245 } 246 /* 247 * bmp_pos is the current bit position inside the bitmap. We use 248 * bmp_initial_pos to determine whether or not to do a zone switch. 249 */ 250 bmp_pos = bmp_initial_pos = zone_start; 251 252 /* Loop until all clusters are allocated, i.e. clusters == 0. */ 253 clusters = count; 254 rlpos = rlsize = 0; 255 mapping = lcnbmp_vi->i_mapping; 256 i_size = i_size_read(lcnbmp_vi); 257 while (1) { 258 ntfs_debug("Start of outer while loop: done_zones 0x%x, " 259 "search_zone %i, pass %i, zone_start 0x%llx, " 260 "zone_end 0x%llx, bmp_initial_pos 0x%llx, " 261 "bmp_pos 0x%llx, rlpos %i, rlsize %i.", 262 done_zones, search_zone, pass, 263 (unsigned long long)zone_start, 264 (unsigned long long)zone_end, 265 (unsigned long long)bmp_initial_pos, 266 (unsigned long long)bmp_pos, rlpos, rlsize); 267 /* Loop until we run out of free clusters. */ 268 last_read_pos = bmp_pos >> 3; 269 ntfs_debug("last_read_pos 0x%llx.", 270 (unsigned long long)last_read_pos); 271 if (last_read_pos > i_size) { 272 ntfs_debug("End of attribute reached. " 273 "Skipping to zone_pass_done."); 274 goto zone_pass_done; 275 } 276 if (likely(page)) { 277 if (need_writeback) { 278 ntfs_debug("Marking page dirty."); 279 flush_dcache_page(page); 280 set_page_dirty(page); 281 need_writeback = 0; 282 } 283 ntfs_unmap_page(page); 284 } 285 page = ntfs_map_page(mapping, last_read_pos >> 286 PAGE_CACHE_SHIFT); 287 if (IS_ERR(page)) { 288 err = PTR_ERR(page); 289 ntfs_error(vol->sb, "Failed to map page."); 290 goto out; 291 } 292 buf_size = last_read_pos & ~PAGE_CACHE_MASK; 293 buf = page_address(page) + buf_size; 294 buf_size = PAGE_CACHE_SIZE - buf_size; 295 if (unlikely(last_read_pos + buf_size > i_size)) 296 buf_size = i_size - last_read_pos; 297 buf_size <<= 3; 298 lcn = bmp_pos & 7; 299 bmp_pos &= ~(LCN)7; 300 ntfs_debug("Before inner while loop: buf_size %i, lcn 0x%llx, " 301 "bmp_pos 0x%llx, need_writeback %i.", buf_size, 302 (unsigned long long)lcn, 303 (unsigned long long)bmp_pos, need_writeback); 304 while (lcn < buf_size && lcn + bmp_pos < zone_end) { 305 byte = buf + (lcn >> 3); 306 ntfs_debug("In inner while loop: buf_size %i, " 307 "lcn 0x%llx, bmp_pos 0x%llx, " 308 "need_writeback %i, byte ofs 0x%x, " 309 "*byte 0x%x.", buf_size, 310 (unsigned long long)lcn, 311 (unsigned long long)bmp_pos, 312 need_writeback, 313 (unsigned int)(lcn >> 3), 314 (unsigned int)*byte); 315 /* Skip full bytes. */ 316 if (*byte == 0xff) { 317 lcn = (lcn + 8) & ~(LCN)7; 318 ntfs_debug("Continuing while loop 1."); 319 continue; 320 } 321 bit = 1 << (lcn & 7); 322 ntfs_debug("bit 0x%x.", bit); 323 /* If the bit is already set, go onto the next one. */ 324 if (*byte & bit) { 325 lcn++; 326 ntfs_debug("Continuing while loop 2."); 327 continue; 328 } 329 /* 330 * Allocate more memory if needed, including space for 331 * the terminator element. 332 * ntfs_malloc_nofs() operates on whole pages only. 333 */ 334 if ((rlpos + 2) * sizeof(*rl) > rlsize) { 335 runlist_element *rl2; 336 337 ntfs_debug("Reallocating memory."); 338 if (!rl) 339 ntfs_debug("First free bit is at LCN " 340 "0x%llx.", 341 (unsigned long long) 342 (lcn + bmp_pos)); 343 rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE); 344 if (unlikely(!rl2)) { 345 err = -ENOMEM; 346 ntfs_error(vol->sb, "Failed to " 347 "allocate memory."); 348 goto out; 349 } 350 memcpy(rl2, rl, rlsize); 351 ntfs_free(rl); 352 rl = rl2; 353 rlsize += PAGE_SIZE; 354 ntfs_debug("Reallocated memory, rlsize 0x%x.", 355 rlsize); 356 } 357 /* Allocate the bitmap bit. */ 358 *byte |= bit; 359 /* We need to write this bitmap page to disk. */ 360 need_writeback = 1; 361 ntfs_debug("*byte 0x%x, need_writeback is set.", 362 (unsigned int)*byte); 363 /* 364 * Coalesce with previous run if adjacent LCNs. 365 * Otherwise, append a new run. 366 */ 367 ntfs_debug("Adding run (lcn 0x%llx, len 0x%llx), " 368 "prev_lcn 0x%llx, lcn 0x%llx, " 369 "bmp_pos 0x%llx, prev_run_len 0x%llx, " 370 "rlpos %i.", 371 (unsigned long long)(lcn + bmp_pos), 372 1ULL, (unsigned long long)prev_lcn, 373 (unsigned long long)lcn, 374 (unsigned long long)bmp_pos, 375 (unsigned long long)prev_run_len, 376 rlpos); 377 if (prev_lcn == lcn + bmp_pos - prev_run_len && rlpos) { 378 ntfs_debug("Coalescing to run (lcn 0x%llx, " 379 "len 0x%llx).", 380 (unsigned long long) 381 rl[rlpos - 1].lcn, 382 (unsigned long long) 383 rl[rlpos - 1].length); 384 rl[rlpos - 1].length = ++prev_run_len; 385 ntfs_debug("Run now (lcn 0x%llx, len 0x%llx), " 386 "prev_run_len 0x%llx.", 387 (unsigned long long) 388 rl[rlpos - 1].lcn, 389 (unsigned long long) 390 rl[rlpos - 1].length, 391 (unsigned long long) 392 prev_run_len); 393 } else { 394 if (likely(rlpos)) { 395 ntfs_debug("Adding new run, (previous " 396 "run lcn 0x%llx, " 397 "len 0x%llx).", 398 (unsigned long long) 399 rl[rlpos - 1].lcn, 400 (unsigned long long) 401 rl[rlpos - 1].length); 402 rl[rlpos].vcn = rl[rlpos - 1].vcn + 403 prev_run_len; 404 } else { 405 ntfs_debug("Adding new run, is first " 406 "run."); 407 rl[rlpos].vcn = start_vcn; 408 } 409 rl[rlpos].lcn = prev_lcn = lcn + bmp_pos; 410 rl[rlpos].length = prev_run_len = 1; 411 rlpos++; 412 } 413 /* Done? */ 414 if (!--clusters) { 415 LCN tc; 416 /* 417 * Update the current zone position. Positions 418 * of already scanned zones have been updated 419 * during the respective zone switches. 420 */ 421 tc = lcn + bmp_pos + 1; 422 ntfs_debug("Done. Updating current zone " 423 "position, tc 0x%llx, " 424 "search_zone %i.", 425 (unsigned long long)tc, 426 search_zone); 427 switch (search_zone) { 428 case 1: 429 ntfs_debug("Before checks, " 430 "vol->mft_zone_pos " 431 "0x%llx.", 432 (unsigned long long) 433 vol->mft_zone_pos); 434 if (tc >= vol->mft_zone_end) { 435 vol->mft_zone_pos = 436 vol->mft_lcn; 437 if (!vol->mft_zone_end) 438 vol->mft_zone_pos = 0; 439 } else if ((bmp_initial_pos >= 440 vol->mft_zone_pos || 441 tc > vol->mft_zone_pos) 442 && tc >= vol->mft_lcn) 443 vol->mft_zone_pos = tc; 444 ntfs_debug("After checks, " 445 "vol->mft_zone_pos " 446 "0x%llx.", 447 (unsigned long long) 448 vol->mft_zone_pos); 449 break; 450 case 2: 451 ntfs_debug("Before checks, " 452 "vol->data1_zone_pos " 453 "0x%llx.", 454 (unsigned long long) 455 vol->data1_zone_pos); 456 if (tc >= vol->nr_clusters) 457 vol->data1_zone_pos = 458 vol->mft_zone_end; 459 else if ((bmp_initial_pos >= 460 vol->data1_zone_pos || 461 tc > vol->data1_zone_pos) 462 && tc >= vol->mft_zone_end) 463 vol->data1_zone_pos = tc; 464 ntfs_debug("After checks, " 465 "vol->data1_zone_pos " 466 "0x%llx.", 467 (unsigned long long) 468 vol->data1_zone_pos); 469 break; 470 case 4: 471 ntfs_debug("Before checks, " 472 "vol->data2_zone_pos " 473 "0x%llx.", 474 (unsigned long long) 475 vol->data2_zone_pos); 476 if (tc >= vol->mft_zone_start) 477 vol->data2_zone_pos = 0; 478 else if (bmp_initial_pos >= 479 vol->data2_zone_pos || 480 tc > vol->data2_zone_pos) 481 vol->data2_zone_pos = tc; 482 ntfs_debug("After checks, " 483 "vol->data2_zone_pos " 484 "0x%llx.", 485 (unsigned long long) 486 vol->data2_zone_pos); 487 break; 488 default: 489 BUG(); 490 } 491 ntfs_debug("Finished. Going to out."); 492 goto out; 493 } 494 lcn++; 495 } 496 bmp_pos += buf_size; 497 ntfs_debug("After inner while loop: buf_size 0x%x, lcn " 498 "0x%llx, bmp_pos 0x%llx, need_writeback %i.", 499 buf_size, (unsigned long long)lcn, 500 (unsigned long long)bmp_pos, need_writeback); 501 if (bmp_pos < zone_end) { 502 ntfs_debug("Continuing outer while loop, " 503 "bmp_pos 0x%llx, zone_end 0x%llx.", 504 (unsigned long long)bmp_pos, 505 (unsigned long long)zone_end); 506 continue; 507 } 508 zone_pass_done: /* Finished with the current zone pass. */ 509 ntfs_debug("At zone_pass_done, pass %i.", pass); 510 if (pass == 1) { 511 /* 512 * Now do pass 2, scanning the first part of the zone 513 * we omitted in pass 1. 514 */ 515 pass = 2; 516 zone_end = zone_start; 517 switch (search_zone) { 518 case 1: /* mft_zone */ 519 zone_start = vol->mft_zone_start; 520 break; 521 case 2: /* data1_zone */ 522 zone_start = vol->mft_zone_end; 523 break; 524 case 4: /* data2_zone */ 525 zone_start = 0; 526 break; 527 default: 528 BUG(); 529 } 530 /* Sanity check. */ 531 if (zone_end < zone_start) 532 zone_end = zone_start; 533 bmp_pos = zone_start; 534 ntfs_debug("Continuing outer while loop, pass 2, " 535 "zone_start 0x%llx, zone_end 0x%llx, " 536 "bmp_pos 0x%llx.", 537 (unsigned long long)zone_start, 538 (unsigned long long)zone_end, 539 (unsigned long long)bmp_pos); 540 continue; 541 } /* pass == 2 */ 542 done_zones_check: 543 ntfs_debug("At done_zones_check, search_zone %i, done_zones " 544 "before 0x%x, done_zones after 0x%x.", 545 search_zone, done_zones, 546 done_zones | search_zone); 547 done_zones |= search_zone; 548 if (done_zones < 7) { 549 ntfs_debug("Switching zone."); 550 /* Now switch to the next zone we haven't done yet. */ 551 pass = 1; 552 switch (search_zone) { 553 case 1: 554 ntfs_debug("Switching from mft zone to data1 " 555 "zone."); 556 /* Update mft zone position. */ 557 if (rlpos) { 558 LCN tc; 559 560 ntfs_debug("Before checks, " 561 "vol->mft_zone_pos " 562 "0x%llx.", 563 (unsigned long long) 564 vol->mft_zone_pos); 565 tc = rl[rlpos - 1].lcn + 566 rl[rlpos - 1].length; 567 if (tc >= vol->mft_zone_end) { 568 vol->mft_zone_pos = 569 vol->mft_lcn; 570 if (!vol->mft_zone_end) 571 vol->mft_zone_pos = 0; 572 } else if ((bmp_initial_pos >= 573 vol->mft_zone_pos || 574 tc > vol->mft_zone_pos) 575 && tc >= vol->mft_lcn) 576 vol->mft_zone_pos = tc; 577 ntfs_debug("After checks, " 578 "vol->mft_zone_pos " 579 "0x%llx.", 580 (unsigned long long) 581 vol->mft_zone_pos); 582 } 583 /* Switch from mft zone to data1 zone. */ 584 switch_to_data1_zone: search_zone = 2; 585 zone_start = bmp_initial_pos = 586 vol->data1_zone_pos; 587 zone_end = vol->nr_clusters; 588 if (zone_start == vol->mft_zone_end) 589 pass = 2; 590 if (zone_start >= zone_end) { 591 vol->data1_zone_pos = zone_start = 592 vol->mft_zone_end; 593 pass = 2; 594 } 595 break; 596 case 2: 597 ntfs_debug("Switching from data1 zone to " 598 "data2 zone."); 599 /* Update data1 zone position. */ 600 if (rlpos) { 601 LCN tc; 602 603 ntfs_debug("Before checks, " 604 "vol->data1_zone_pos " 605 "0x%llx.", 606 (unsigned long long) 607 vol->data1_zone_pos); 608 tc = rl[rlpos - 1].lcn + 609 rl[rlpos - 1].length; 610 if (tc >= vol->nr_clusters) 611 vol->data1_zone_pos = 612 vol->mft_zone_end; 613 else if ((bmp_initial_pos >= 614 vol->data1_zone_pos || 615 tc > vol->data1_zone_pos) 616 && tc >= vol->mft_zone_end) 617 vol->data1_zone_pos = tc; 618 ntfs_debug("After checks, " 619 "vol->data1_zone_pos " 620 "0x%llx.", 621 (unsigned long long) 622 vol->data1_zone_pos); 623 } 624 /* Switch from data1 zone to data2 zone. */ 625 search_zone = 4; 626 zone_start = bmp_initial_pos = 627 vol->data2_zone_pos; 628 zone_end = vol->mft_zone_start; 629 if (!zone_start) 630 pass = 2; 631 if (zone_start >= zone_end) { 632 vol->data2_zone_pos = zone_start = 633 bmp_initial_pos = 0; 634 pass = 2; 635 } 636 break; 637 case 4: 638 ntfs_debug("Switching from data2 zone to " 639 "data1 zone."); 640 /* Update data2 zone position. */ 641 if (rlpos) { 642 LCN tc; 643 644 ntfs_debug("Before checks, " 645 "vol->data2_zone_pos " 646 "0x%llx.", 647 (unsigned long long) 648 vol->data2_zone_pos); 649 tc = rl[rlpos - 1].lcn + 650 rl[rlpos - 1].length; 651 if (tc >= vol->mft_zone_start) 652 vol->data2_zone_pos = 0; 653 else if (bmp_initial_pos >= 654 vol->data2_zone_pos || 655 tc > vol->data2_zone_pos) 656 vol->data2_zone_pos = tc; 657 ntfs_debug("After checks, " 658 "vol->data2_zone_pos " 659 "0x%llx.", 660 (unsigned long long) 661 vol->data2_zone_pos); 662 } 663 /* Switch from data2 zone to data1 zone. */ 664 goto switch_to_data1_zone; 665 default: 666 BUG(); 667 } 668 ntfs_debug("After zone switch, search_zone %i, " 669 "pass %i, bmp_initial_pos 0x%llx, " 670 "zone_start 0x%llx, zone_end 0x%llx.", 671 search_zone, pass, 672 (unsigned long long)bmp_initial_pos, 673 (unsigned long long)zone_start, 674 (unsigned long long)zone_end); 675 bmp_pos = zone_start; 676 if (zone_start == zone_end) { 677 ntfs_debug("Empty zone, going to " 678 "done_zones_check."); 679 /* Empty zone. Don't bother searching it. */ 680 goto done_zones_check; 681 } 682 ntfs_debug("Continuing outer while loop."); 683 continue; 684 } /* done_zones == 7 */ 685 ntfs_debug("All zones are finished."); 686 /* 687 * All zones are finished! If DATA_ZONE, shrink mft zone. If 688 * MFT_ZONE, we have really run out of space. 689 */ 690 mft_zone_size = vol->mft_zone_end - vol->mft_zone_start; 691 ntfs_debug("vol->mft_zone_start 0x%llx, vol->mft_zone_end " 692 "0x%llx, mft_zone_size 0x%llx.", 693 (unsigned long long)vol->mft_zone_start, 694 (unsigned long long)vol->mft_zone_end, 695 (unsigned long long)mft_zone_size); 696 if (zone == MFT_ZONE || mft_zone_size <= 0) { 697 ntfs_debug("No free clusters left, going to out."); 698 /* Really no more space left on device. */ 699 err = -ENOSPC; 700 goto out; 701 } /* zone == DATA_ZONE && mft_zone_size > 0 */ 702 ntfs_debug("Shrinking mft zone."); 703 zone_end = vol->mft_zone_end; 704 mft_zone_size >>= 1; 705 if (mft_zone_size > 0) 706 vol->mft_zone_end = vol->mft_zone_start + mft_zone_size; 707 else /* mft zone and data2 zone no longer exist. */ 708 vol->data2_zone_pos = vol->mft_zone_start = 709 vol->mft_zone_end = 0; 710 if (vol->mft_zone_pos >= vol->mft_zone_end) { 711 vol->mft_zone_pos = vol->mft_lcn; 712 if (!vol->mft_zone_end) 713 vol->mft_zone_pos = 0; 714 } 715 bmp_pos = zone_start = bmp_initial_pos = 716 vol->data1_zone_pos = vol->mft_zone_end; 717 search_zone = 2; 718 pass = 2; 719 done_zones &= ~2; 720 ntfs_debug("After shrinking mft zone, mft_zone_size 0x%llx, " 721 "vol->mft_zone_start 0x%llx, " 722 "vol->mft_zone_end 0x%llx, " 723 "vol->mft_zone_pos 0x%llx, search_zone 2, " 724 "pass 2, dones_zones 0x%x, zone_start 0x%llx, " 725 "zone_end 0x%llx, vol->data1_zone_pos 0x%llx, " 726 "continuing outer while loop.", 727 (unsigned long long)mft_zone_size, 728 (unsigned long long)vol->mft_zone_start, 729 (unsigned long long)vol->mft_zone_end, 730 (unsigned long long)vol->mft_zone_pos, 731 done_zones, (unsigned long long)zone_start, 732 (unsigned long long)zone_end, 733 (unsigned long long)vol->data1_zone_pos); 734 } 735 ntfs_debug("After outer while loop."); 736 out: 737 ntfs_debug("At out."); 738 /* Add runlist terminator element. */ 739 if (likely(rl)) { 740 rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length; 741 rl[rlpos].lcn = is_extension ? LCN_ENOENT : LCN_RL_NOT_MAPPED; 742 rl[rlpos].length = 0; 743 } 744 if (likely(page && !IS_ERR(page))) { 745 if (need_writeback) { 746 ntfs_debug("Marking page dirty."); 747 flush_dcache_page(page); 748 set_page_dirty(page); 749 need_writeback = 0; 750 } 751 ntfs_unmap_page(page); 752 } 753 if (likely(!err)) { 754 up_write(&vol->lcnbmp_lock); 755 ntfs_debug("Done."); 756 return rl; 757 } 758 ntfs_error(vol->sb, "Failed to allocate clusters, aborting " 759 "(error %i).", err); 760 if (rl) { 761 int err2; 762 763 if (err == -ENOSPC) 764 ntfs_debug("Not enough space to complete allocation, " 765 "err -ENOSPC, first free lcn 0x%llx, " 766 "could allocate up to 0x%llx " 767 "clusters.", 768 (unsigned long long)rl[0].lcn, 769 (unsigned long long)(count - clusters)); 770 /* Deallocate all allocated clusters. */ 771 ntfs_debug("Attempting rollback..."); 772 err2 = ntfs_cluster_free_from_rl_nolock(vol, rl); 773 if (err2) { 774 ntfs_error(vol->sb, "Failed to rollback (error %i). " 775 "Leaving inconsistent metadata! " 776 "Unmount and run chkdsk.", err2); 777 NVolSetErrors(vol); 778 } 779 /* Free the runlist. */ 780 ntfs_free(rl); 781 } else if (err == -ENOSPC) 782 ntfs_debug("No space left at all, err = -ENOSPC, first free " 783 "lcn = 0x%llx.", 784 (long long)vol->data1_zone_pos); 785 up_write(&vol->lcnbmp_lock); 786 return ERR_PTR(err); 787 } 788 789 /** 790 * __ntfs_cluster_free - free clusters on an ntfs volume 791 * @ni: ntfs inode whose runlist describes the clusters to free 792 * @start_vcn: vcn in the runlist of @ni at which to start freeing clusters 793 * @count: number of clusters to free or -1 for all clusters 794 * @ctx: active attribute search context if present or NULL if not 795 * @is_rollback: true if this is a rollback operation 796 * 797 * Free @count clusters starting at the cluster @start_vcn in the runlist 798 * described by the vfs inode @ni. 799 * 800 * If @count is -1, all clusters from @start_vcn to the end of the runlist are 801 * deallocated. Thus, to completely free all clusters in a runlist, use 802 * @start_vcn = 0 and @count = -1. 803 * 804 * If @ctx is specified, it is an active search context of @ni and its base mft 805 * record. This is needed when __ntfs_cluster_free() encounters unmapped 806 * runlist fragments and allows their mapping. If you do not have the mft 807 * record mapped, you can specify @ctx as NULL and __ntfs_cluster_free() will 808 * perform the necessary mapping and unmapping. 809 * 810 * Note, __ntfs_cluster_free() saves the state of @ctx on entry and restores it 811 * before returning. Thus, @ctx will be left pointing to the same attribute on 812 * return as on entry. However, the actual pointers in @ctx may point to 813 * different memory locations on return, so you must remember to reset any 814 * cached pointers from the @ctx, i.e. after the call to __ntfs_cluster_free(), 815 * you will probably want to do: 816 * m = ctx->mrec; 817 * a = ctx->attr; 818 * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that 819 * you cache ctx->mrec in a variable @m of type MFT_RECORD *. 820 * 821 * @is_rollback should always be 'false', it is for internal use to rollback 822 * errors. You probably want to use ntfs_cluster_free() instead. 823 * 824 * Note, __ntfs_cluster_free() does not modify the runlist, so you have to 825 * remove from the runlist or mark sparse the freed runs later. 826 * 827 * Return the number of deallocated clusters (not counting sparse ones) on 828 * success and -errno on error. 829 * 830 * WARNING: If @ctx is supplied, regardless of whether success or failure is 831 * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx 832 * is no longer valid, i.e. you need to either call 833 * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it. 834 * In that case PTR_ERR(@ctx->mrec) will give you the error code for 835 * why the mapping of the old inode failed. 836 * 837 * Locking: - The runlist described by @ni must be locked for writing on entry 838 * and is locked on return. Note the runlist may be modified when 839 * needed runlist fragments need to be mapped. 840 * - The volume lcn bitmap must be unlocked on entry and is unlocked 841 * on return. 842 * - This function takes the volume lcn bitmap lock for writing and 843 * modifies the bitmap contents. 844 * - If @ctx is NULL, the base mft record of @ni must not be mapped on 845 * entry and it will be left unmapped on return. 846 * - If @ctx is not NULL, the base mft record must be mapped on entry 847 * and it will be left mapped on return. 848 */ 849 s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count, 850 ntfs_attr_search_ctx *ctx, const bool is_rollback) 851 { 852 s64 delta, to_free, total_freed, real_freed; 853 ntfs_volume *vol; 854 struct inode *lcnbmp_vi; 855 runlist_element *rl; 856 int err; 857 858 BUG_ON(!ni); 859 ntfs_debug("Entering for i_ino 0x%lx, start_vcn 0x%llx, count " 860 "0x%llx.%s", ni->mft_no, (unsigned long long)start_vcn, 861 (unsigned long long)count, 862 is_rollback ? " (rollback)" : ""); 863 vol = ni->vol; 864 lcnbmp_vi = vol->lcnbmp_ino; 865 BUG_ON(!lcnbmp_vi); 866 BUG_ON(start_vcn < 0); 867 BUG_ON(count < -1); 868 /* 869 * Lock the lcn bitmap for writing but only if not rolling back. We 870 * must hold the lock all the way including through rollback otherwise 871 * rollback is not possible because once we have cleared a bit and 872 * dropped the lock, anyone could have set the bit again, thus 873 * allocating the cluster for another use. 874 */ 875 if (likely(!is_rollback)) 876 down_write(&vol->lcnbmp_lock); 877 878 total_freed = real_freed = 0; 879 880 rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, ctx); 881 if (IS_ERR(rl)) { 882 if (!is_rollback) 883 ntfs_error(vol->sb, "Failed to find first runlist " 884 "element (error %li), aborting.", 885 PTR_ERR(rl)); 886 err = PTR_ERR(rl); 887 goto err_out; 888 } 889 if (unlikely(rl->lcn < LCN_HOLE)) { 890 if (!is_rollback) 891 ntfs_error(vol->sb, "First runlist element has " 892 "invalid lcn, aborting."); 893 err = -EIO; 894 goto err_out; 895 } 896 /* Find the starting cluster inside the run that needs freeing. */ 897 delta = start_vcn - rl->vcn; 898 899 /* The number of clusters in this run that need freeing. */ 900 to_free = rl->length - delta; 901 if (count >= 0 && to_free > count) 902 to_free = count; 903 904 if (likely(rl->lcn >= 0)) { 905 /* Do the actual freeing of the clusters in this run. */ 906 err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn + delta, 907 to_free, likely(!is_rollback) ? 0 : 1); 908 if (unlikely(err)) { 909 if (!is_rollback) 910 ntfs_error(vol->sb, "Failed to clear first run " 911 "(error %i), aborting.", err); 912 goto err_out; 913 } 914 /* We have freed @to_free real clusters. */ 915 real_freed = to_free; 916 }; 917 /* Go to the next run and adjust the number of clusters left to free. */ 918 ++rl; 919 if (count >= 0) 920 count -= to_free; 921 922 /* Keep track of the total "freed" clusters, including sparse ones. */ 923 total_freed = to_free; 924 /* 925 * Loop over the remaining runs, using @count as a capping value, and 926 * free them. 927 */ 928 for (; rl->length && count != 0; ++rl) { 929 if (unlikely(rl->lcn < LCN_HOLE)) { 930 VCN vcn; 931 932 /* Attempt to map runlist. */ 933 vcn = rl->vcn; 934 rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx); 935 if (IS_ERR(rl)) { 936 err = PTR_ERR(rl); 937 if (!is_rollback) 938 ntfs_error(vol->sb, "Failed to map " 939 "runlist fragment or " 940 "failed to find " 941 "subsequent runlist " 942 "element."); 943 goto err_out; 944 } 945 if (unlikely(rl->lcn < LCN_HOLE)) { 946 if (!is_rollback) 947 ntfs_error(vol->sb, "Runlist element " 948 "has invalid lcn " 949 "(0x%llx).", 950 (unsigned long long) 951 rl->lcn); 952 err = -EIO; 953 goto err_out; 954 } 955 } 956 /* The number of clusters in this run that need freeing. */ 957 to_free = rl->length; 958 if (count >= 0 && to_free > count) 959 to_free = count; 960 961 if (likely(rl->lcn >= 0)) { 962 /* Do the actual freeing of the clusters in the run. */ 963 err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn, 964 to_free, likely(!is_rollback) ? 0 : 1); 965 if (unlikely(err)) { 966 if (!is_rollback) 967 ntfs_error(vol->sb, "Failed to clear " 968 "subsequent run."); 969 goto err_out; 970 } 971 /* We have freed @to_free real clusters. */ 972 real_freed += to_free; 973 } 974 /* Adjust the number of clusters left to free. */ 975 if (count >= 0) 976 count -= to_free; 977 978 /* Update the total done clusters. */ 979 total_freed += to_free; 980 } 981 if (likely(!is_rollback)) 982 up_write(&vol->lcnbmp_lock); 983 984 BUG_ON(count > 0); 985 986 /* We are done. Return the number of actually freed clusters. */ 987 ntfs_debug("Done."); 988 return real_freed; 989 err_out: 990 if (is_rollback) 991 return err; 992 /* If no real clusters were freed, no need to rollback. */ 993 if (!real_freed) { 994 up_write(&vol->lcnbmp_lock); 995 return err; 996 } 997 /* 998 * Attempt to rollback and if that succeeds just return the error code. 999 * If rollback fails, set the volume errors flag, emit an error 1000 * message, and return the error code. 1001 */ 1002 delta = __ntfs_cluster_free(ni, start_vcn, total_freed, ctx, true); 1003 if (delta < 0) { 1004 ntfs_error(vol->sb, "Failed to rollback (error %i). Leaving " 1005 "inconsistent metadata! Unmount and run " 1006 "chkdsk.", (int)delta); 1007 NVolSetErrors(vol); 1008 } 1009 up_write(&vol->lcnbmp_lock); 1010 ntfs_error(vol->sb, "Aborting (error %i).", err); 1011 return err; 1012 } 1013 1014 #endif /* NTFS_RW */
Cache object: 56b8a80f0f6819584de555a64975dd1d
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