1 /**
2 * lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2002-2004 Anton Altaparmakov
5 * Copyright (c) 2004 Yura Pakhuchiy
6 *
7 * This program/include file is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program/include file is distributed in the hope that it will be
13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program (in the main directory of the Linux-NTFS
19 * distribution in the file COPYING); if not, write to the Free Software
20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #ifdef HAVE_STDLIB_H
28 #include <stdlib.h>
29 #endif
30 #ifdef HAVE_STDIO_H
31 #include <stdio.h>
32 #endif
33 #ifdef HAVE_ERRNO_H
34 #include <errno.h>
35 #endif
36
37 #include "compat.h"
38 #include "types.h"
39 #include "attrib.h"
40 #include "bitmap.h"
41 #include "debug.h"
42 #include "runlist.h"
43 #include "volume.h"
44 #include "lcnalloc.h"
45 #include "logging.h"
46
47 /**
48 * ntfs_cluster_alloc - allocate clusters on an ntfs volume
49 * @vol: mounted ntfs volume on which to allocate the clusters
50 * @start_vcn: vcn to use for the first allocated cluster
51 * @count: number of clusters to allocate
52 * @start_lcn: starting lcn at which to allocate the clusters (or -1 if none)
53 * @zone: zone from which to allocate the clusters
54 *
55 * Allocate @count clusters preferably starting at cluster @start_lcn or at the
56 * current allocator position if @start_lcn is -1, on the mounted ntfs volume
57 * @vol. @zone is either DATA_ZONE for allocation of normal clusters and
58 * MFT_ZONE for allocation of clusters for the master file table, i.e. the
59 * $MFT/$DATA attribute.
60 *
61 * On success return a runlist describing the allocated cluster(s).
62 *
63 * On error return NULL with errno set to the error code.
64 *
65 * Notes on the allocation algorithm
66 * =================================
67 *
68 * There are two data zones. First is the area between the end of the mft zone
69 * and the end of the volume, and second is the area between the start of the
70 * volume and the start of the mft zone. On unmodified/standard NTFS 1.x
71 * volumes, the second data zone doesn't exist due to the mft zone being
72 * expanded to cover the start of the volume in order to reserve space for the
73 * mft bitmap attribute.
74 *
75 * This is not the prettiest function but the complexity stems from the need of
76 * implementing the mft vs data zoned approach and from the fact that we have
77 * access to the lcn bitmap in portions of up to 8192 bytes at a time, so we
78 * need to cope with crossing over boundaries of two buffers. Further, the fact
79 * that the allocator allows for caller supplied hints as to the location of
80 * where allocation should begin and the fact that the allocator keeps track of
81 * where in the data zones the next natural allocation should occur, contribute
82 * to the complexity of the function. But it should all be worthwhile, because
83 * this allocator should: 1) be a full implementation of the MFT zone approach
84 * used by Windows, 2) cause reduction in fragmentation as much as possible,
85 * and 3) be speedy in allocations (the code is not optimized for speed, but
86 * the algorithm is, so further speed improvements are probably possible).
87 *
88 * FIXME: We should be monitoring cluster allocation and increment the MFT zone
89 * size dynamically but this is something for the future. We will just cause
90 * heavier fragmentation by not doing it and I am not even sure Windows would
91 * grow the MFT zone dynamically, so it might even be correct not to do this.
92 * The overhead in doing dynamic MFT zone expansion would be very large and
93 * unlikely worth the effort. (AIA)
94 *
95 * TODO: I have added in double the required zone position pointer wrap around
96 * logic which can be optimized to having only one of the two logic sets.
97 * However, having the double logic will work fine, but if we have only one of
98 * the sets and we get it wrong somewhere, then we get into trouble, so
99 * removing the duplicate logic requires _very_ careful consideration of _all_
100 * possible code paths. So at least for now, I am leaving the double logic -
101 * better safe than sorry... (AIA)
102 */
103 runlist *ntfs_cluster_alloc(ntfs_volume *vol, VCN start_vcn, s64 count,
104 LCN start_lcn, const NTFS_CLUSTER_ALLOCATION_ZONES zone)
105 {
106 LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
107 LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
108 s64 clusters, br;
109 runlist *rl = NULL, *trl;
110 u8 *buf, *byte;
111 int err = 0, rlpos, rlsize, buf_size;
112 u8 pass, done_zones, search_zone, need_writeback, bit;
113
114 ntfs_log_trace("Entering with count = 0x%llx, start_lcn = 0x%llx, zone = "
115 "%s_ZONE.\n", (long long)count, (long long)start_lcn,
116 zone == MFT_ZONE ? "MFT" : "DATA");
117 if (!vol || count < 0 || start_lcn < -1 || !vol->lcnbmp_na ||
118 (s8)zone < FIRST_ZONE || zone > LAST_ZONE) {
119 ntfs_log_trace("Invalid arguments!\n");
120 errno = EINVAL;
121 return NULL;
122 }
123
124 /* Return empty runlist if @count == 0 */
125 if (!count) {
126 rl = ntfs_malloc(0x1000);
127 if (!rl)
128 return NULL;
129 rl[0].vcn = start_vcn;
130 rl[0].lcn = LCN_RL_NOT_MAPPED;
131 rl[0].length = 0;
132 return rl;
133 }
134
135 /* Allocate memory. */
136 buf = (u8*)ntfs_malloc(8192);
137 if (!buf)
138 return NULL;
139 /*
140 * If no specific @start_lcn was requested, use the current data zone
141 * position, otherwise use the requested @start_lcn but make sure it
142 * lies outside the mft zone. Also set done_zones to 0 (no zones done)
143 * and pass depending on whether we are starting inside a zone (1) or
144 * at the beginning of a zone (2). If requesting from the MFT_ZONE,
145 * we either start at the current position within the mft zone or at
146 * the specified position. If the latter is out of bounds then we start
147 * at the beginning of the MFT_ZONE.
148 */
149 done_zones = 0;
150 pass = 1;
151 /*
152 * zone_start and zone_end are the current search range. search_zone
153 * is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of
154 * volume) and 4 for data zone 2 (start of volume till start of mft
155 * zone).
156 */
157 zone_start = start_lcn;
158 if (zone_start < 0) {
159 if (zone == DATA_ZONE)
160 zone_start = vol->data1_zone_pos;
161 else
162 zone_start = vol->mft_zone_pos;
163 if (!zone_start) {
164 /*
165 * Zone starts at beginning of volume which means a
166 * single pass is sufficient.
167 */
168 pass = 2;
169 }
170 } else if (zone == DATA_ZONE && zone_start >= vol->mft_zone_start &&
171 zone_start < vol->mft_zone_end) {
172 zone_start = vol->mft_zone_end;
173 /*
174 * Starting at beginning of data1_zone which means a single
175 * pass in this zone is sufficient.
176 */
177 pass = 2;
178 } else if (zone == MFT_ZONE && (zone_start < vol->mft_zone_start ||
179 zone_start >= vol->mft_zone_end)) {
180 zone_start = vol->mft_lcn;
181 if (!vol->mft_zone_end)
182 zone_start = 0;
183 /*
184 * Starting at beginning of volume which means a single pass
185 * is sufficient.
186 */
187 pass = 2;
188 }
189 if (zone == MFT_ZONE) {
190 zone_end = vol->mft_zone_end;
191 search_zone = 1;
192 } else /* if (zone == DATA_ZONE) */ {
193 /* Skip searching the mft zone. */
194 done_zones |= 1;
195 if (zone_start >= vol->mft_zone_end) {
196 zone_end = vol->nr_clusters;
197 search_zone = 2;
198 } else {
199 zone_end = vol->mft_zone_start;
200 search_zone = 4;
201 }
202 }
203 /*
204 * bmp_pos is the current bit position inside the bitmap. We use
205 * bmp_initial_pos to determine whether or not to do a zone switch.
206 */
207 bmp_pos = bmp_initial_pos = zone_start;
208
209 /* Loop until all clusters are allocated, i.e. clusters == 0. */
210 clusters = count;
211 rlpos = rlsize = 0;
212 while (1) {
213 ntfs_log_trace("Start of outer while loop: done_zones = 0x%x, "
214 "search_zone = %i, pass = %i, zone_start = "
215 "0x%llx, zone_end = 0x%llx, bmp_initial_pos = "
216 "0x%llx, bmp_pos = 0x%llx, rlpos = %i, rlsize = "
217 "%i.\n", done_zones, search_zone, pass,
218 (long long)zone_start, (long long)zone_end,
219 (long long)bmp_initial_pos, (long long)bmp_pos,
220 rlpos, rlsize);
221 /* Loop until we run out of free clusters. */
222 last_read_pos = bmp_pos >> 3;
223 ntfs_log_trace("last_read_pos = 0x%llx.\n", (long long)last_read_pos);
224 br = ntfs_attr_pread(vol->lcnbmp_na, last_read_pos, 8192, buf);
225 if (br <= 0) {
226 if (!br) {
227 /* Reached end of attribute. */
228 ntfs_log_trace("End of attribute reached. Skipping "
229 "to zone_pass_done.\n");
230 goto zone_pass_done;
231 }
232 err = errno;
233 ntfs_log_trace("ntfs_attr_pread() failed. Aborting.\n");
234 goto err_ret;
235 }
236 /*
237 * We might have read less than 8192 bytes if we are close to
238 * the end of the attribute.
239 */
240 buf_size = (int)br << 3;
241 lcn = bmp_pos & 7;
242 bmp_pos &= ~7;
243 need_writeback = 0;
244 ntfs_log_trace("Before inner while loop: buf_size = %i, lcn = "
245 "0x%llx, bmp_pos = 0x%llx, need_writeback = %i.\n",
246 buf_size, (long long)lcn, (long long)bmp_pos,
247 need_writeback);
248 while (lcn < buf_size && lcn + bmp_pos < zone_end) {
249 byte = buf + (lcn >> 3);
250 ntfs_log_trace("In inner while loop: buf_size = %i, lcn = "
251 "0x%llx, bmp_pos = 0x%llx, "
252 "need_writeback = %i, byte ofs = 0x%x, "
253 "*byte = 0x%x.\n", buf_size,
254 (long long)lcn, (long long)bmp_pos,
255 need_writeback, (unsigned int)(lcn >> 3),
256 (unsigned int)*byte);
257 /* Skip full bytes. */
258 if (*byte == 0xff) {
259 lcn = (lcn + 8) & ~7;
260 ntfs_log_trace("continuing while loop 1.\n");
261 continue;
262 }
263 bit = 1 << (lcn & 7);
264 ntfs_log_trace("bit = %i.\n", bit);
265 /* If the bit is already set, go onto the next one. */
266 if (*byte & bit) {
267 lcn++;
268 ntfs_log_trace("continuing while loop 2.\n");
269 continue;
270 }
271 /* Reallocate memory if necessary. */
272 if ((rlpos + 2) * (int)sizeof(runlist) >= rlsize) {
273 ntfs_log_trace("Reallocating space.\n");
274 if (!rl)
275 ntfs_log_trace("First free bit is at LCN = "
276 "0x%llx.\n", (long long)(lcn + bmp_pos));
277 rlsize += 4096;
278 trl = (runlist*)realloc(rl, rlsize);
279 if (!trl) {
280 err = ENOMEM;
281 ntfs_log_trace("Failed to allocate memory, "
282 "going to wb_err_ret.\n");
283 goto wb_err_ret;
284 }
285 rl = trl;
286 ntfs_log_trace("Reallocated memory, rlsize = "
287 "0x%x.\n", rlsize);
288 }
289 /* Allocate the bitmap bit. */
290 *byte |= bit;
291 vol->nr_free_clusters--;
292 /* We need to write this bitmap buffer back to disk! */
293 need_writeback = 1;
294 ntfs_log_trace("*byte = 0x%x, need_writeback is set.\n",
295 (unsigned int)*byte);
296 /*
297 * Coalesce with previous run if adjacent LCNs.
298 * Otherwise, append a new run.
299 */
300 ntfs_log_trace("Adding run (lcn 0x%llx, len 0x%llx), "
301 "prev_lcn = 0x%llx, lcn = 0x%llx, "
302 "bmp_pos = 0x%llx, prev_run_len = "
303 "0x%llx, rlpos = %i.\n",
304 (long long)(lcn + bmp_pos), 1LL,
305 (long long)prev_lcn, (long long)lcn,
306 (long long)bmp_pos,
307 (long long)prev_run_len, rlpos);
308 if (prev_lcn == lcn + bmp_pos - prev_run_len && rlpos) {
309 ntfs_log_trace("Coalescing to run (lcn 0x%llx, len "
310 "0x%llx).\n",
311 (long long)rl[rlpos - 1].lcn,
312 (long long) rl[rlpos - 1].length);
313 rl[rlpos - 1].length = ++prev_run_len;
314 ntfs_log_trace("Run now (lcn 0x%llx, len 0x%llx), "
315 "prev_run_len = 0x%llx.\n",
316 (long long)rl[rlpos - 1].lcn,
317 (long long)rl[rlpos - 1].length,
318 (long long)prev_run_len);
319 } else {
320 if (rlpos) {
321 ntfs_log_trace("Adding new run, (previous "
322 "run lcn 0x%llx, len 0x%llx).\n",
323 (long long) rl[rlpos - 1].lcn,
324 (long long) rl[rlpos - 1].length);
325 rl[rlpos].vcn = rl[rlpos - 1].vcn +
326 prev_run_len;
327 } else {
328 ntfs_log_trace("Adding new run, is first run.\n");
329 rl[rlpos].vcn = start_vcn;
330 }
331 rl[rlpos].lcn = prev_lcn = lcn + bmp_pos;
332 rl[rlpos].length = prev_run_len = 1;
333 rlpos++;
334 }
335 /* Done? */
336 if (!--clusters) {
337 LCN tc;
338 /*
339 * Update the current zone position. Positions
340 * of already scanned zones have been updated
341 * during the respective zone switches.
342 */
343 tc = lcn + bmp_pos + 1;
344 ntfs_log_trace("Done. Updating current zone "
345 "position, tc = 0x%llx, search_zone = %i.\n",
346 (long long)tc, search_zone);
347 switch (search_zone) {
348 case 1:
349 ntfs_log_trace("Before checks, vol->mft_zone_pos = 0x%llx.\n",
350 (long long) vol->mft_zone_pos);
351 if (tc >= vol->mft_zone_end) {
352 vol->mft_zone_pos =
353 vol->mft_lcn;
354 if (!vol->mft_zone_end)
355 vol->mft_zone_pos = 0;
356 } else if ((bmp_initial_pos >=
357 vol->mft_zone_pos ||
358 tc > vol->mft_zone_pos)
359 && tc >= vol->mft_lcn)
360 vol->mft_zone_pos = tc;
361 ntfs_log_trace("After checks, vol->mft_zone_pos = 0x%llx.\n",
362 (long long) vol->mft_zone_pos);
363 break;
364 case 2:
365 ntfs_log_trace("Before checks, vol->data1_zone_pos = 0x%llx.\n",
366 (long long) vol->data1_zone_pos);
367 if (tc >= vol->nr_clusters)
368 vol->data1_zone_pos =
369 vol->mft_zone_end;
370 else if ((bmp_initial_pos >=
371 vol->data1_zone_pos ||
372 tc > vol->data1_zone_pos)
373 && tc >= vol->mft_zone_end)
374 vol->data1_zone_pos = tc;
375 ntfs_log_trace("After checks, vol->data1_zone_pos = 0x%llx.\n",
376 (long long) vol->data1_zone_pos);
377 break;
378 case 4:
379 ntfs_log_trace("Before checks, vol->data2_zone_pos = 0x%llx.\n",
380 (long long) vol->data2_zone_pos);
381 if (tc >= vol->mft_zone_start)
382 vol->data2_zone_pos = 0;
383 else if (bmp_initial_pos >=
384 vol->data2_zone_pos ||
385 tc > vol->data2_zone_pos)
386 vol->data2_zone_pos = tc;
387 ntfs_log_trace("After checks, vol->data2_zone_pos = 0x%llx.\n",
388 (long long) vol->data2_zone_pos);
389 break;
390 default:
391 free(rl);
392 free(buf);
393 NTFS_BUG("switch (search_zone) 1");
394 return NULL;
395 }
396 ntfs_log_trace("Going to done_ret.\n");
397 goto done_ret;
398 }
399 lcn++;
400 }
401 bmp_pos += buf_size;
402 ntfs_log_trace("After inner while loop: buf_size = 0x%x, lcn = "
403 "0x%llx, bmp_pos = 0x%llx, need_writeback = %i.\n",
404 buf_size, (long long)lcn,
405 (long long)bmp_pos, need_writeback);
406 if (need_writeback) {
407 s64 bw;
408 ntfs_log_trace("Writing back.\n");
409 need_writeback = 0;
410 bw = ntfs_attr_pwrite(vol->lcnbmp_na, last_read_pos,
411 br, buf);
412 if (bw != br) {
413 if (bw == -1)
414 err = errno;
415 else
416 err = EIO;
417 ntfs_log_trace("Bitmap writeback failed in read next "
418 "buffer code path with error code %i.\n", err);
419 goto err_ret;
420 }
421 }
422 if (bmp_pos < zone_end) {
423 ntfs_log_trace("Continuing outer while loop, bmp_pos = "
424 "0x%llx, zone_end = 0x%llx.\n",
425 (long long)bmp_pos,
426 (long long)zone_end);
427 continue;
428 }
429 zone_pass_done: /* Finished with the current zone pass. */
430 ntfs_log_trace("At zone_pass_done, pass = %i.\n", pass);
431 if (pass == 1) {
432 /*
433 * Now do pass 2, scanning the first part of the zone
434 * we omitted in pass 1.
435 */
436 pass = 2;
437 zone_end = zone_start;
438 switch (search_zone) {
439 case 1: /* mft_zone */
440 zone_start = vol->mft_zone_start;
441 break;
442 case 2: /* data1_zone */
443 zone_start = vol->mft_zone_end;
444 break;
445 case 4: /* data2_zone */
446 zone_start = 0;
447 break;
448 default:
449 NTFS_BUG("switch (search_zone) 2");
450 }
451 /* Sanity check. */
452 if (zone_end < zone_start)
453 zone_end = zone_start;
454 bmp_pos = zone_start;
455 ntfs_log_trace("Continuing outer while loop, pass = 2, "
456 "zone_start = 0x%llx, zone_end = "
457 "0x%llx, bmp_pos = 0x%llx.\n",
458 zone_start, zone_end, bmp_pos);
459 continue;
460 } /* pass == 2 */
461 done_zones_check:
462 ntfs_log_trace("At done_zones_check, search_zone = %i, done_zones "
463 "before = 0x%x, done_zones after = 0x%x.\n",
464 search_zone, done_zones, done_zones | search_zone);
465 done_zones |= search_zone;
466 if (done_zones < 7) {
467 ntfs_log_trace("Switching zone.\n");
468 /* Now switch to the next zone we haven't done yet. */
469 pass = 1;
470 switch (search_zone) {
471 case 1:
472 ntfs_log_trace("Switching from mft zone to data1 "
473 "zone.\n");
474 /* Update mft zone position. */
475 if (rlpos) {
476 LCN tc;
477 ntfs_log_trace("Before checks, vol->mft_zone_pos = 0x%llx.\n",
478 (long long) vol->mft_zone_pos);
479 tc = rl[rlpos - 1].lcn +
480 rl[rlpos - 1].length;
481 if (tc >= vol->mft_zone_end) {
482 vol->mft_zone_pos =
483 vol->mft_lcn;
484 if (!vol->mft_zone_end)
485 vol->mft_zone_pos = 0;
486 } else if ((bmp_initial_pos >=
487 vol->mft_zone_pos ||
488 tc > vol->mft_zone_pos)
489 && tc >= vol->mft_lcn)
490 vol->mft_zone_pos = tc;
491 ntfs_log_trace("After checks, vol->mft_zone_pos = 0x%llx.\n",
492 (long long) vol->mft_zone_pos);
493 }
494 /* Switch from mft zone to data1 zone. */
495 switch_to_data1_zone: search_zone = 2;
496 zone_start = bmp_initial_pos =
497 vol->data1_zone_pos;
498 zone_end = vol->nr_clusters;
499 if (zone_start == vol->mft_zone_end)
500 pass = 2;
501 if (zone_start >= zone_end) {
502 vol->data1_zone_pos = zone_start =
503 vol->mft_zone_end;
504 pass = 2;
505 }
506 break;
507 case 2:
508 ntfs_log_trace("Switching from data1 zone to data2 "
509 "zone.\n");
510 /* Update data1 zone position. */
511 if (rlpos) {
512 LCN tc;
513 ntfs_log_trace("Before checks, vol->data1_zone_pos = 0x%llx.\n",
514 (long long) vol->data1_zone_pos);
515 tc = rl[rlpos - 1].lcn +
516 rl[rlpos - 1].length;
517 if (tc >= vol->nr_clusters)
518 vol->data1_zone_pos =
519 vol->mft_zone_end;
520 else if ((bmp_initial_pos >=
521 vol->data1_zone_pos ||
522 tc > vol->data1_zone_pos)
523 && tc >= vol->mft_zone_end)
524 vol->data1_zone_pos = tc;
525 ntfs_log_trace("After checks, vol->data1_zone_pos = 0x%llx.\n",
526 (long long) vol->data1_zone_pos);
527 }
528 /* Switch from data1 zone to data2 zone. */
529 search_zone = 4;
530 zone_start = bmp_initial_pos =
531 vol->data2_zone_pos;
532 zone_end = vol->mft_zone_start;
533 if (!zone_start)
534 pass = 2;
535 if (zone_start >= zone_end) {
536 vol->data2_zone_pos = zone_start =
537 bmp_initial_pos = 0;
538 pass = 2;
539 }
540 break;
541 case 4:
542 ntfs_log_debug("Switching from data2 zone to data1 "
543 "zone.\n");
544 /* Update data2 zone position. */
545 if (rlpos) {
546 LCN tc;
547 ntfs_log_trace("Before checks, vol->data2_zone_pos = 0x%llx.\n",
548 (long long) vol->data2_zone_pos);
549 tc = rl[rlpos - 1].lcn +
550 rl[rlpos - 1].length;
551 if (tc >= vol->mft_zone_start)
552 vol->data2_zone_pos = 0;
553 else if (bmp_initial_pos >=
554 vol->data2_zone_pos ||
555 tc > vol->data2_zone_pos)
556 vol->data2_zone_pos = tc;
557 ntfs_log_trace("After checks, vol->data2_zone_pos = 0x%llx.\n",
558 (long long) vol->data2_zone_pos);
559 }
560 /* Switch from data2 zone to data1 zone. */
561 goto switch_to_data1_zone; /* See above. */
562 default:
563 NTFS_BUG("switch (search_zone) 3");
564 }
565 ntfs_log_trace("After zone switch, search_zone = %i, pass = "
566 "%i, bmp_initial_pos = 0x%llx, "
567 "zone_start = 0x%llx, zone_end = "
568 "0x%llx.\n", search_zone, pass,
569 (long long)bmp_initial_pos,
570 (long long)zone_start,
571 (long long)zone_end);
572 bmp_pos = zone_start;
573 if (zone_start == zone_end) {
574 ntfs_log_trace("Empty zone, going to "
575 "done_zones_check.\n");
576 /* Empty zone. Don't bother searching it. */
577 goto done_zones_check;
578 }
579 ntfs_log_trace("Continuing outer while loop.\n");
580 continue;
581 } /* done_zones == 7 */
582 ntfs_log_trace("All zones are finished.\n");
583 /*
584 * All zones are finished! If DATA_ZONE, shrink mft zone. If
585 * MFT_ZONE, we have really run out of space.
586 */
587 mft_zone_size = vol->mft_zone_end - vol->mft_zone_start;
588 ntfs_log_trace("vol->mft_zone_start = 0x%llx, vol->mft_zone_end = "
589 "0x%llx, mft_zone_size = 0x%llx.\n",
590 (long long)vol->mft_zone_start,
591 (long long)vol->mft_zone_end,
592 (long long)mft_zone_size);
593 if (zone == MFT_ZONE || mft_zone_size <= 0) {
594 ntfs_log_trace("No free clusters left, going to err_ret.\n");
595 /* Really no more space left on device. */
596 err = ENOSPC;
597 goto err_ret;
598 } /* zone == DATA_ZONE && mft_zone_size > 0 */
599 ntfs_log_trace("Shrinking mft zone.\n");
600 zone_end = vol->mft_zone_end;
601 mft_zone_size >>= 1;
602 if (mft_zone_size > 0)
603 vol->mft_zone_end = vol->mft_zone_start + mft_zone_size;
604 else /* mft zone and data2 zone no longer exist. */
605 vol->data2_zone_pos = vol->mft_zone_start =
606 vol->mft_zone_end = 0;
607 if (vol->mft_zone_pos >= vol->mft_zone_end) {
608 vol->mft_zone_pos = vol->mft_lcn;
609 if (!vol->mft_zone_end)
610 vol->mft_zone_pos = 0;
611 }
612 bmp_pos = zone_start = bmp_initial_pos =
613 vol->data1_zone_pos = vol->mft_zone_end;
614 search_zone = 2;
615 pass = 2;
616 done_zones &= ~2;
617 ntfs_log_trace("After shrinking mft zone, mft_zone_size = 0x%llx, "
618 "vol->mft_zone_start = 0x%llx, "
619 "vol->mft_zone_end = 0x%llx, vol->mft_zone_pos "
620 "= 0x%llx, search_zone = 2, pass = 2, "
621 "dones_zones = 0x%x, zone_start = 0x%llx, "
622 "zone_end = 0x%llx, vol->data1_zone_pos = "
623 "0x%llx, continuing outer while loop.\n",
624 (long long)mft_zone_size,
625 (long long)vol->mft_zone_start,
626 (long long)vol->mft_zone_end,
627 (long long)vol->mft_zone_pos,
628 done_zones,
629 (long long)zone_start,
630 (long long)zone_end,
631 (long long)vol->data1_zone_pos);
632 }
633 ntfs_log_debug("After outer while loop.\n");
634 done_ret:
635 ntfs_log_debug("At done_ret.\n");
636 /* Add runlist terminator element. */
637 rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
638 rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
639 rl[rlpos].length = 0;
640 if (need_writeback) {
641 s64 bw;
642 ntfs_log_trace("Writing back.\n");
643 need_writeback = 0;
644 bw = ntfs_attr_pwrite(vol->lcnbmp_na, last_read_pos, br, buf);
645 if (bw != br) {
646 if (bw < 0)
647 err = errno;
648 else
649 err = EIO;
650 ntfs_log_trace("Bitmap writeback failed in done code path "
651 "with error code %i.\n", err);
652 goto err_ret;
653 }
654 }
655 done_err_ret:
656 ntfs_log_debug("At done_err_ret (follows done_ret).\n");
657 free(buf);
658 /* Done! */
659 if (!err)
660 return rl;
661 ntfs_log_trace("Failed to allocate clusters. Returning with error code "
662 "%i.\n", err);
663 errno = err;
664 return NULL;
665 wb_err_ret:
666 ntfs_log_trace("At wb_err_ret.\n");
667 if (need_writeback) {
668 s64 bw;
669 ntfs_log_trace("Writing back.\n");
670 need_writeback = 0;
671 bw = ntfs_attr_pwrite(vol->lcnbmp_na, last_read_pos, br, buf);
672 if (bw != br) {
673 if (bw < 0)
674 err = errno;
675 else
676 err = EIO;
677 ntfs_log_trace("Bitmap writeback failed in error code path "
678 "with error code %i.\n", err);
679 }
680 }
681 err_ret:
682 ntfs_log_trace("At err_ret.\n");
683 if (rl) {
684 if (err == ENOSPC) {
685 ntfs_log_trace("err = ENOSPC, first free lcn = 0x%llx, could "
686 "allocate up to = 0x%llx clusters.\n",
687 (long long)rl[0].lcn,
688 (long long)count - clusters);
689 }
690 /* Add runlist terminator element. */
691 rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
692 rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
693 rl[rlpos].length = 0;
694 /* Deallocate all allocated clusters. */
695 ntfs_log_trace("Deallocating allocated clusters.\n");
696 ntfs_cluster_free_from_rl(vol, rl);
697 /* Free the runlist. */
698 free(rl);
699 rl = NULL;
700 } else {
701 if (err == ENOSPC) {
702 ntfs_log_trace("No space left at all, err = ENOSPC, first "
703 "free lcn = 0x%llx.\n",
704 (long long)vol->data1_zone_pos);
705 }
706 }
707 ntfs_log_trace("rl = NULL, going to done_err_ret.\n");
708 goto done_err_ret;
709 }
710
711 /**
712 * ntfs_cluster_free_from_rl - free clusters from runlist
713 * @vol: mounted ntfs volume on which to free the clusters
714 * @rl: runlist from which deallocate clusters
715 *
716 * On success return 0 and on error return -1 with errno set to the error code.
717 */
718 int ntfs_cluster_free_from_rl(ntfs_volume *vol, runlist *rl)
719 {
720 ntfs_log_trace("Entering.\n");
721
722 for (; rl->length; rl++) {
723
724 ntfs_log_trace("Dealloc lcn 0x%llx, len 0x%llx.\n",
725 (long long)rl->lcn, (long long)rl->length);
726
727 if (rl->lcn >= 0 && ntfs_bitmap_clear_run(vol->lcnbmp_na,
728 rl->lcn, rl->length)) {
729 int eo = errno;
730 ntfs_log_trace("Eeek! Deallocation of clusters failed.\n");
731 errno = eo;
732 return -1;
733 }
734 }
735 return 0;
736 }
737
738 /**
739 * ntfs_cluster_free - free clusters on an ntfs volume
740 * @vol: mounted ntfs volume on which to free the clusters
741 * @na: attribute whose runlist describes the clusters to free
742 * @start_vcn: vcn in @rl at which to start freeing clusters
743 * @count: number of clusters to free or -1 for all clusters
744 *
745 * Free @count clusters starting at the cluster @start_vcn in the runlist
746 * described by the attribute @na from the mounted ntfs volume @vol.
747 *
748 * If @count is -1, all clusters from @start_vcn to the end of the runlist
749 * are deallocated.
750 *
751 * On success return the number of deallocated clusters (not counting sparse
752 * clusters) and on error return -1 with errno set to the error code.
753 */
754 int ntfs_cluster_free(ntfs_volume *vol, ntfs_attr *na, VCN start_vcn, s64 count)
755 {
756 runlist *rl;
757 s64 nr_freed, delta, to_free;
758
759 if (!vol || !vol->lcnbmp_na || !na || start_vcn < 0 ||
760 (count < 0 && count != -1)) {
761 ntfs_log_trace("Invalid arguments!\n");
762 errno = EINVAL;
763 return -1;
764 }
765 ntfs_log_trace("Entering for inode 0x%llx, attr 0x%x, count 0x%llx, "
766 "vcn 0x%llx.\n", (unsigned long long)na->ni->mft_no,
767 na->type, (long long)count, (long long)start_vcn);
768
769 rl = ntfs_attr_find_vcn(na, start_vcn);
770 if (!rl) {
771 if (errno == ENOENT)
772 return 0;
773 else
774 return -1;
775 }
776
777 if (rl->lcn < 0 && rl->lcn != LCN_HOLE) {
778 errno = EIO;
779 return -1;
780 }
781
782 /* Find the starting cluster inside the run that needs freeing. */
783 delta = start_vcn - rl->vcn;
784
785 /* The number of clusters in this run that need freeing. */
786 to_free = rl->length - delta;
787 if (count >= 0 && to_free > count)
788 to_free = count;
789
790 if (rl->lcn != LCN_HOLE) {
791 /* Do the actual freeing of the clusters in this run. */
792 if (ntfs_bitmap_clear_run(vol->lcnbmp_na, rl->lcn + delta,
793 to_free))
794 return -1;
795 /* We have freed @to_free real clusters. */
796 nr_freed = to_free;
797 } else {
798 /* No real clusters were freed. */
799 nr_freed = 0;
800 }
801
802 /* Go to the next run and adjust the number of clusters left to free. */
803 ++rl;
804 if (count >= 0)
805 count -= to_free;
806
807 /*
808 * Loop over the remaining runs, using @count as a capping value, and
809 * free them.
810 */
811 for (; rl->length && count != 0; ++rl) {
812 // FIXME: Need to try ntfs_attr_map_runlist() for attribute
813 // list support! (AIA)
814 if (rl->lcn < 0 && rl->lcn != LCN_HOLE) {
815 // FIXME: Eeek! We need rollback! (AIA)
816 ntfs_log_trace("Eeek! invalid lcn (= %lli). Should attempt "
817 "to map runlist! Leaving inconsistent "
818 "metadata!\n", (long long)rl->lcn);
819 errno = EIO;
820 return -1;
821 }
822
823 /* The number of clusters in this run that need freeing. */
824 to_free = rl->length;
825 if (count >= 0 && to_free > count)
826 to_free = count;
827
828 if (rl->lcn != LCN_HOLE) {
829 /* Do the actual freeing of the clusters in the run. */
830 if (ntfs_bitmap_clear_run(vol->lcnbmp_na, rl->lcn,
831 to_free)) {
832 int eo = errno;
833
834 // FIXME: Eeek! We need rollback! (AIA)
835 ntfs_log_trace("Eeek! bitmap clear run failed. "
836 "Leaving inconsistent metadata!\n");
837 errno = eo;
838 return -1;
839 }
840 /* We have freed @to_free real clusters. */
841 nr_freed += to_free;
842 }
843
844 if (count >= 0)
845 count -= to_free;
846 }
847
848 if (count != -1 && count != 0) {
849 // FIXME: Eeek! BUG()
850 ntfs_log_trace("Eeek! count still not zero (= %lli). Leaving "
851 "inconsistent metadata!\n", (long long)count);
852 errno = EIO;
853 return -1;
854 }
855
856 /* Done. Return the number of actual clusters that were freed. */
857 return nr_freed;
858 }