aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ntfs/lcnalloc.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ntfs/lcnalloc.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/ntfs/lcnalloc.c')
-rw-r--r--fs/ntfs/lcnalloc.c1002
1 files changed, 1002 insertions, 0 deletions
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
new file mode 100644
index 000000000000..23fd911078b1
--- /dev/null
+++ b/fs/ntfs/lcnalloc.c
@@ -0,0 +1,1002 @@
1/*
2 * lcnalloc.c - Cluster (de)allocation code. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2004 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 */
50int 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 for (; rl->length; rl++) {
58 int err;
59
60 if (rl->lcn < 0)
61 continue;
62 err = ntfs_bitmap_clear_run(lcnbmp_vi, rl->lcn, rl->length);
63 if (unlikely(err && (!ret || ret == ENOMEM) && ret != err))
64 ret = err;
65 }
66 ntfs_debug("Done.");
67 return ret;
68}
69
70/**
71 * ntfs_cluster_alloc - allocate clusters on an ntfs volume
72 * @vol: mounted ntfs volume on which to allocate the clusters
73 * @start_vcn: vcn to use for the first allocated cluster
74 * @count: number of clusters to allocate
75 * @start_lcn: starting lcn at which to allocate the clusters (or -1 if none)
76 * @zone: zone from which to allocate the clusters
77 *
78 * Allocate @count clusters preferably starting at cluster @start_lcn or at the
79 * current allocator position if @start_lcn is -1, on the mounted ntfs volume
80 * @vol. @zone is either DATA_ZONE for allocation of normal clusters or
81 * MFT_ZONE for allocation of clusters for the master file table, i.e. the
82 * $MFT/$DATA attribute.
83 *
84 * @start_vcn specifies the vcn of the first allocated cluster. This makes
85 * merging the resulting runlist with the old runlist easier.
86 *
87 * You need to check the return value with IS_ERR(). If this is false, the
88 * function was successful and the return value is a runlist describing the
89 * allocated cluster(s). If IS_ERR() is true, the function failed and
90 * PTR_ERR() gives you the error code.
91 *
92 * Notes on the allocation algorithm
93 * =================================
94 *
95 * There are two data zones. First is the area between the end of the mft zone
96 * and the end of the volume, and second is the area between the start of the
97 * volume and the start of the mft zone. On unmodified/standard NTFS 1.x
98 * volumes, the second data zone does not exist due to the mft zone being
99 * expanded to cover the start of the volume in order to reserve space for the
100 * mft bitmap attribute.
101 *
102 * This is not the prettiest function but the complexity stems from the need of
103 * implementing the mft vs data zoned approach and from the fact that we have
104 * access to the lcn bitmap in portions of up to 8192 bytes at a time, so we
105 * need to cope with crossing over boundaries of two buffers. Further, the
106 * fact that the allocator allows for caller supplied hints as to the location
107 * of where allocation should begin and the fact that the allocator keeps track
108 * of where in the data zones the next natural allocation should occur,
109 * contribute to the complexity of the function. But it should all be
110 * worthwhile, because this allocator should: 1) be a full implementation of
111 * the MFT zone approach used by Windows NT, 2) cause reduction in
112 * fragmentation, and 3) be speedy in allocations (the code is not optimized
113 * for speed, but the algorithm is, so further speed improvements are probably
114 * possible).
115 *
116 * FIXME: We should be monitoring cluster allocation and increment the MFT zone
117 * size dynamically but this is something for the future. We will just cause
118 * heavier fragmentation by not doing it and I am not even sure Windows would
119 * grow the MFT zone dynamically, so it might even be correct not to do this.
120 * The overhead in doing dynamic MFT zone expansion would be very large and
121 * unlikely worth the effort. (AIA)
122 *
123 * TODO: I have added in double the required zone position pointer wrap around
124 * logic which can be optimized to having only one of the two logic sets.
125 * However, having the double logic will work fine, but if we have only one of
126 * the sets and we get it wrong somewhere, then we get into trouble, so
127 * removing the duplicate logic requires _very_ careful consideration of _all_
128 * possible code paths. So at least for now, I am leaving the double logic -
129 * better safe than sorry... (AIA)
130 *
131 * Locking: - The volume lcn bitmap must be unlocked on entry and is unlocked
132 * on return.
133 * - This function takes the volume lcn bitmap lock for writing and
134 * modifies the bitmap contents.
135 */
136runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
137 const s64 count, const LCN start_lcn,
138 const NTFS_CLUSTER_ALLOCATION_ZONES zone)
139{
140 LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
141 LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
142 s64 clusters;
143 struct inode *lcnbmp_vi;
144 runlist_element *rl = NULL;
145 struct address_space *mapping;
146 struct page *page = NULL;
147 u8 *buf, *byte;
148 int err = 0, rlpos, rlsize, buf_size;
149 u8 pass, done_zones, search_zone, need_writeback = 0, bit;
150
151 ntfs_debug("Entering for start_vcn 0x%llx, count 0x%llx, start_lcn "
152 "0x%llx, zone %s_ZONE.", (unsigned long long)start_vcn,
153 (unsigned long long)count,
154 (unsigned long long)start_lcn,
155 zone == MFT_ZONE ? "MFT" : "DATA");
156 BUG_ON(!vol);
157 lcnbmp_vi = vol->lcnbmp_ino;
158 BUG_ON(!lcnbmp_vi);
159 BUG_ON(start_vcn < 0);
160 BUG_ON(count < 0);
161 BUG_ON(start_lcn < -1);
162 BUG_ON(zone < FIRST_ZONE);
163 BUG_ON(zone > LAST_ZONE);
164
165 /* Return empty runlist if @count == 0 */
166 // FIXME: Do we want to just return NULL instead? (AIA)
167 if (!count) {
168 rl = ntfs_malloc_nofs(PAGE_SIZE);
169 if (!rl)
170 return ERR_PTR(-ENOMEM);
171 rl[0].vcn = start_vcn;
172 rl[0].lcn = LCN_RL_NOT_MAPPED;
173 rl[0].length = 0;
174 return rl;
175 }
176 /* Take the lcnbmp lock for writing. */
177 down_write(&vol->lcnbmp_lock);
178 /*
179 * If no specific @start_lcn was requested, use the current data zone
180 * position, otherwise use the requested @start_lcn but make sure it
181 * lies outside the mft zone. Also set done_zones to 0 (no zones done)
182 * and pass depending on whether we are starting inside a zone (1) or
183 * at the beginning of a zone (2). If requesting from the MFT_ZONE,
184 * we either start at the current position within the mft zone or at
185 * the specified position. If the latter is out of bounds then we start
186 * at the beginning of the MFT_ZONE.
187 */
188 done_zones = 0;
189 pass = 1;
190 /*
191 * zone_start and zone_end are the current search range. search_zone
192 * is 1 for mft zone, 2 for data zone 1 (end of mft zone till end of
193 * volume) and 4 for data zone 2 (start of volume till start of mft
194 * zone).
195 */
196 zone_start = start_lcn;
197 if (zone_start < 0) {
198 if (zone == DATA_ZONE)
199 zone_start = vol->data1_zone_pos;
200 else
201 zone_start = vol->mft_zone_pos;
202 if (!zone_start) {
203 /*
204 * Zone starts at beginning of volume which means a
205 * single pass is sufficient.
206 */
207 pass = 2;
208 }
209 } else if (zone == DATA_ZONE && zone_start >= vol->mft_zone_start &&
210 zone_start < vol->mft_zone_end) {
211 zone_start = vol->mft_zone_end;
212 /*
213 * Starting at beginning of data1_zone which means a single
214 * pass in this zone is sufficient.
215 */
216 pass = 2;
217 } else if (zone == MFT_ZONE && (zone_start < vol->mft_zone_start ||
218 zone_start >= vol->mft_zone_end)) {
219 zone_start = vol->mft_lcn;
220 if (!vol->mft_zone_end)
221 zone_start = 0;
222 /*
223 * Starting at beginning of volume which means a single pass
224 * is sufficient.
225 */
226 pass = 2;
227 }
228 if (zone == MFT_ZONE) {
229 zone_end = vol->mft_zone_end;
230 search_zone = 1;
231 } else /* if (zone == DATA_ZONE) */ {
232 /* Skip searching the mft zone. */
233 done_zones |= 1;
234 if (zone_start >= vol->mft_zone_end) {
235 zone_end = vol->nr_clusters;
236 search_zone = 2;
237 } else {
238 zone_end = vol->mft_zone_start;
239 search_zone = 4;
240 }
241 }
242 /*
243 * bmp_pos is the current bit position inside the bitmap. We use
244 * bmp_initial_pos to determine whether or not to do a zone switch.
245 */
246 bmp_pos = bmp_initial_pos = zone_start;
247
248 /* Loop until all clusters are allocated, i.e. clusters == 0. */
249 clusters = count;
250 rlpos = rlsize = 0;
251 mapping = lcnbmp_vi->i_mapping;
252 while (1) {
253 ntfs_debug("Start of outer while loop: done_zones 0x%x, "
254 "search_zone %i, pass %i, zone_start 0x%llx, "
255 "zone_end 0x%llx, bmp_initial_pos 0x%llx, "
256 "bmp_pos 0x%llx, rlpos %i, rlsize %i.",
257 done_zones, search_zone, pass,
258 (unsigned long long)zone_start,
259 (unsigned long long)zone_end,
260 (unsigned long long)bmp_initial_pos,
261 (unsigned long long)bmp_pos, rlpos, rlsize);
262 /* Loop until we run out of free clusters. */
263 last_read_pos = bmp_pos >> 3;
264 ntfs_debug("last_read_pos 0x%llx.",
265 (unsigned long long)last_read_pos);
266 if (last_read_pos > lcnbmp_vi->i_size) {
267 ntfs_debug("End of attribute reached. "
268 "Skipping to zone_pass_done.");
269 goto zone_pass_done;
270 }
271 if (likely(page)) {
272 if (need_writeback) {
273 ntfs_debug("Marking page dirty.");
274 flush_dcache_page(page);
275 set_page_dirty(page);
276 need_writeback = 0;
277 }
278 ntfs_unmap_page(page);
279 }
280 page = ntfs_map_page(mapping, last_read_pos >>
281 PAGE_CACHE_SHIFT);
282 if (IS_ERR(page)) {
283 err = PTR_ERR(page);
284 ntfs_error(vol->sb, "Failed to map page.");
285 goto out;
286 }
287 buf_size = last_read_pos & ~PAGE_CACHE_MASK;
288 buf = page_address(page) + buf_size;
289 buf_size = PAGE_CACHE_SIZE - buf_size;
290 if (unlikely(last_read_pos + buf_size > lcnbmp_vi->i_size))
291 buf_size = lcnbmp_vi->i_size - last_read_pos;
292 buf_size <<= 3;
293 lcn = bmp_pos & 7;
294 bmp_pos &= ~7;
295 ntfs_debug("Before inner while loop: buf_size %i, lcn 0x%llx, "
296 "bmp_pos 0x%llx, need_writeback %i.", buf_size,
297 (unsigned long long)lcn,
298 (unsigned long long)bmp_pos, need_writeback);
299 while (lcn < buf_size && lcn + bmp_pos < zone_end) {
300 byte = buf + (lcn >> 3);
301 ntfs_debug("In inner while loop: buf_size %i, "
302 "lcn 0x%llx, bmp_pos 0x%llx, "
303 "need_writeback %i, byte ofs 0x%x, "
304 "*byte 0x%x.", buf_size,
305 (unsigned long long)lcn,
306 (unsigned long long)bmp_pos,
307 need_writeback,
308 (unsigned int)(lcn >> 3),
309 (unsigned int)*byte);
310 /* Skip full bytes. */
311 if (*byte == 0xff) {
312 lcn = (lcn + 8) & ~7;
313 ntfs_debug("Continuing while loop 1.");
314 continue;
315 }
316 bit = 1 << (lcn & 7);
317 ntfs_debug("bit %i.", bit);
318 /* If the bit is already set, go onto the next one. */
319 if (*byte & bit) {
320 lcn++;
321 ntfs_debug("Continuing while loop 2.");
322 continue;
323 }
324 /*
325 * Allocate more memory if needed, including space for
326 * the terminator element.
327 * ntfs_malloc_nofs() operates on whole pages only.
328 */
329 if ((rlpos + 2) * sizeof(*rl) > rlsize) {
330 runlist_element *rl2;
331
332 ntfs_debug("Reallocating memory.");
333 if (!rl)
334 ntfs_debug("First free bit is at LCN "
335 "0x%llx.",
336 (unsigned long long)
337 (lcn + bmp_pos));
338 rl2 = ntfs_malloc_nofs(rlsize + (int)PAGE_SIZE);
339 if (unlikely(!rl2)) {
340 err = -ENOMEM;
341 ntfs_error(vol->sb, "Failed to "
342 "allocate memory.");
343 goto out;
344 }
345 memcpy(rl2, rl, rlsize);
346 ntfs_free(rl);
347 rl = rl2;
348 rlsize += PAGE_SIZE;
349 ntfs_debug("Reallocated memory, rlsize 0x%x.",
350 rlsize);
351 }
352 /* Allocate the bitmap bit. */
353 *byte |= bit;
354 /* We need to write this bitmap page to disk. */
355 need_writeback = 1;
356 ntfs_debug("*byte 0x%x, need_writeback is set.",
357 (unsigned int)*byte);
358 /*
359 * Coalesce with previous run if adjacent LCNs.
360 * Otherwise, append a new run.
361 */
362 ntfs_debug("Adding run (lcn 0x%llx, len 0x%llx), "
363 "prev_lcn 0x%llx, lcn 0x%llx, "
364 "bmp_pos 0x%llx, prev_run_len 0x%llx, "
365 "rlpos %i.",
366 (unsigned long long)(lcn + bmp_pos),
367 1ULL, (unsigned long long)prev_lcn,
368 (unsigned long long)lcn,
369 (unsigned long long)bmp_pos,
370 (unsigned long long)prev_run_len,
371 rlpos);
372 if (prev_lcn == lcn + bmp_pos - prev_run_len && rlpos) {
373 ntfs_debug("Coalescing to run (lcn 0x%llx, "
374 "len 0x%llx).",
375 (unsigned long long)
376 rl[rlpos - 1].lcn,
377 (unsigned long long)
378 rl[rlpos - 1].length);
379 rl[rlpos - 1].length = ++prev_run_len;
380 ntfs_debug("Run now (lcn 0x%llx, len 0x%llx), "
381 "prev_run_len 0x%llx.",
382 (unsigned long long)
383 rl[rlpos - 1].lcn,
384 (unsigned long long)
385 rl[rlpos - 1].length,
386 (unsigned long long)
387 prev_run_len);
388 } else {
389 if (likely(rlpos)) {
390 ntfs_debug("Adding new run, (previous "
391 "run lcn 0x%llx, "
392 "len 0x%llx).",
393 (unsigned long long)
394 rl[rlpos - 1].lcn,
395 (unsigned long long)
396 rl[rlpos - 1].length);
397 rl[rlpos].vcn = rl[rlpos - 1].vcn +
398 prev_run_len;
399 } else {
400 ntfs_debug("Adding new run, is first "
401 "run.");
402 rl[rlpos].vcn = start_vcn;
403 }
404 rl[rlpos].lcn = prev_lcn = lcn + bmp_pos;
405 rl[rlpos].length = prev_run_len = 1;
406 rlpos++;
407 }
408 /* Done? */
409 if (!--clusters) {
410 LCN tc;
411 /*
412 * Update the current zone position. Positions
413 * of already scanned zones have been updated
414 * during the respective zone switches.
415 */
416 tc = lcn + bmp_pos + 1;
417 ntfs_debug("Done. Updating current zone "
418 "position, tc 0x%llx, "
419 "search_zone %i.",
420 (unsigned long long)tc,
421 search_zone);
422 switch (search_zone) {
423 case 1:
424 ntfs_debug("Before checks, "
425 "vol->mft_zone_pos "
426 "0x%llx.",
427 (unsigned long long)
428 vol->mft_zone_pos);
429 if (tc >= vol->mft_zone_end) {
430 vol->mft_zone_pos =
431 vol->mft_lcn;
432 if (!vol->mft_zone_end)
433 vol->mft_zone_pos = 0;
434 } else if ((bmp_initial_pos >=
435 vol->mft_zone_pos ||
436 tc > vol->mft_zone_pos)
437 && tc >= vol->mft_lcn)
438 vol->mft_zone_pos = tc;
439 ntfs_debug("After checks, "
440 "vol->mft_zone_pos "
441 "0x%llx.",
442 (unsigned long long)
443 vol->mft_zone_pos);
444 break;
445 case 2:
446 ntfs_debug("Before checks, "
447 "vol->data1_zone_pos "
448 "0x%llx.",
449 (unsigned long long)
450 vol->data1_zone_pos);
451 if (tc >= vol->nr_clusters)
452 vol->data1_zone_pos =
453 vol->mft_zone_end;
454 else if ((bmp_initial_pos >=
455 vol->data1_zone_pos ||
456 tc > vol->data1_zone_pos)
457 && tc >= vol->mft_zone_end)
458 vol->data1_zone_pos = tc;
459 ntfs_debug("After checks, "
460 "vol->data1_zone_pos "
461 "0x%llx.",
462 (unsigned long long)
463 vol->data1_zone_pos);
464 break;
465 case 4:
466 ntfs_debug("Before checks, "
467 "vol->data2_zone_pos "
468 "0x%llx.",
469 (unsigned long long)
470 vol->data2_zone_pos);
471 if (tc >= vol->mft_zone_start)
472 vol->data2_zone_pos = 0;
473 else if (bmp_initial_pos >=
474 vol->data2_zone_pos ||
475 tc > vol->data2_zone_pos)
476 vol->data2_zone_pos = tc;
477 ntfs_debug("After checks, "
478 "vol->data2_zone_pos "
479 "0x%llx.",
480 (unsigned long long)
481 vol->data2_zone_pos);
482 break;
483 default:
484 BUG();
485 }
486 ntfs_debug("Finished. Going to out.");
487 goto out;
488 }
489 lcn++;
490 }
491 bmp_pos += buf_size;
492 ntfs_debug("After inner while loop: buf_size 0x%x, lcn "
493 "0x%llx, bmp_pos 0x%llx, need_writeback %i.",
494 buf_size, (unsigned long long)lcn,
495 (unsigned long long)bmp_pos, need_writeback);
496 if (bmp_pos < zone_end) {
497 ntfs_debug("Continuing outer while loop, "
498 "bmp_pos 0x%llx, zone_end 0x%llx.",
499 (unsigned long long)bmp_pos,
500 (unsigned long long)zone_end);
501 continue;
502 }
503zone_pass_done: /* Finished with the current zone pass. */
504 ntfs_debug("At zone_pass_done, pass %i.", pass);
505 if (pass == 1) {
506 /*
507 * Now do pass 2, scanning the first part of the zone
508 * we omitted in pass 1.
509 */
510 pass = 2;
511 zone_end = zone_start;
512 switch (search_zone) {
513 case 1: /* mft_zone */
514 zone_start = vol->mft_zone_start;
515 break;
516 case 2: /* data1_zone */
517 zone_start = vol->mft_zone_end;
518 break;
519 case 4: /* data2_zone */
520 zone_start = 0;
521 break;
522 default:
523 BUG();
524 }
525 /* Sanity check. */
526 if (zone_end < zone_start)
527 zone_end = zone_start;
528 bmp_pos = zone_start;
529 ntfs_debug("Continuing outer while loop, pass 2, "
530 "zone_start 0x%llx, zone_end 0x%llx, "
531 "bmp_pos 0x%llx.",
532 (unsigned long long)zone_start,
533 (unsigned long long)zone_end,
534 (unsigned long long)bmp_pos);
535 continue;
536 } /* pass == 2 */
537done_zones_check:
538 ntfs_debug("At done_zones_check, search_zone %i, done_zones "
539 "before 0x%x, done_zones after 0x%x.",
540 search_zone, done_zones,
541 done_zones | search_zone);
542 done_zones |= search_zone;
543 if (done_zones < 7) {
544 ntfs_debug("Switching zone.");
545 /* Now switch to the next zone we haven't done yet. */
546 pass = 1;
547 switch (search_zone) {
548 case 1:
549 ntfs_debug("Switching from mft zone to data1 "
550 "zone.");
551 /* Update mft zone position. */
552 if (rlpos) {
553 LCN tc;
554
555 ntfs_debug("Before checks, "
556 "vol->mft_zone_pos "
557 "0x%llx.",
558 (unsigned long long)
559 vol->mft_zone_pos);
560 tc = rl[rlpos - 1].lcn +
561 rl[rlpos - 1].length;
562 if (tc >= vol->mft_zone_end) {
563 vol->mft_zone_pos =
564 vol->mft_lcn;
565 if (!vol->mft_zone_end)
566 vol->mft_zone_pos = 0;
567 } else if ((bmp_initial_pos >=
568 vol->mft_zone_pos ||
569 tc > vol->mft_zone_pos)
570 && tc >= vol->mft_lcn)
571 vol->mft_zone_pos = tc;
572 ntfs_debug("After checks, "
573 "vol->mft_zone_pos "
574 "0x%llx.",
575 (unsigned long long)
576 vol->mft_zone_pos);
577 }
578 /* Switch from mft zone to data1 zone. */
579switch_to_data1_zone: search_zone = 2;
580 zone_start = bmp_initial_pos =
581 vol->data1_zone_pos;
582 zone_end = vol->nr_clusters;
583 if (zone_start == vol->mft_zone_end)
584 pass = 2;
585 if (zone_start >= zone_end) {
586 vol->data1_zone_pos = zone_start =
587 vol->mft_zone_end;
588 pass = 2;
589 }
590 break;
591 case 2:
592 ntfs_debug("Switching from data1 zone to "
593 "data2 zone.");
594 /* Update data1 zone position. */
595 if (rlpos) {
596 LCN tc;
597
598 ntfs_debug("Before checks, "
599 "vol->data1_zone_pos "
600 "0x%llx.",
601 (unsigned long long)
602 vol->data1_zone_pos);
603 tc = rl[rlpos - 1].lcn +
604 rl[rlpos - 1].length;
605 if (tc >= vol->nr_clusters)
606 vol->data1_zone_pos =
607 vol->mft_zone_end;
608 else if ((bmp_initial_pos >=
609 vol->data1_zone_pos ||
610 tc > vol->data1_zone_pos)
611 && tc >= vol->mft_zone_end)
612 vol->data1_zone_pos = tc;
613 ntfs_debug("After checks, "
614 "vol->data1_zone_pos "
615 "0x%llx.",
616 (unsigned long long)
617 vol->data1_zone_pos);
618 }
619 /* Switch from data1 zone to data2 zone. */
620 search_zone = 4;
621 zone_start = bmp_initial_pos =
622 vol->data2_zone_pos;
623 zone_end = vol->mft_zone_start;
624 if (!zone_start)
625 pass = 2;
626 if (zone_start >= zone_end) {
627 vol->data2_zone_pos = zone_start =
628 bmp_initial_pos = 0;
629 pass = 2;
630 }
631 break;
632 case 4:
633 ntfs_debug("Switching from data2 zone to "
634 "data1 zone.");
635 /* Update data2 zone position. */
636 if (rlpos) {
637 LCN tc;
638
639 ntfs_debug("Before checks, "
640 "vol->data2_zone_pos "
641 "0x%llx.",
642 (unsigned long long)
643 vol->data2_zone_pos);
644 tc = rl[rlpos - 1].lcn +
645 rl[rlpos - 1].length;
646 if (tc >= vol->mft_zone_start)
647 vol->data2_zone_pos = 0;
648 else if (bmp_initial_pos >=
649 vol->data2_zone_pos ||
650 tc > vol->data2_zone_pos)
651 vol->data2_zone_pos = tc;
652 ntfs_debug("After checks, "
653 "vol->data2_zone_pos "
654 "0x%llx.",
655 (unsigned long long)
656 vol->data2_zone_pos);
657 }
658 /* Switch from data2 zone to data1 zone. */
659 goto switch_to_data1_zone;
660 default:
661 BUG();
662 }
663 ntfs_debug("After zone switch, search_zone %i, "
664 "pass %i, bmp_initial_pos 0x%llx, "
665 "zone_start 0x%llx, zone_end 0x%llx.",
666 search_zone, pass,
667 (unsigned long long)bmp_initial_pos,
668 (unsigned long long)zone_start,
669 (unsigned long long)zone_end);
670 bmp_pos = zone_start;
671 if (zone_start == zone_end) {
672 ntfs_debug("Empty zone, going to "
673 "done_zones_check.");
674 /* Empty zone. Don't bother searching it. */
675 goto done_zones_check;
676 }
677 ntfs_debug("Continuing outer while loop.");
678 continue;
679 } /* done_zones == 7 */
680 ntfs_debug("All zones are finished.");
681 /*
682 * All zones are finished! If DATA_ZONE, shrink mft zone. If
683 * MFT_ZONE, we have really run out of space.
684 */
685 mft_zone_size = vol->mft_zone_end - vol->mft_zone_start;
686 ntfs_debug("vol->mft_zone_start 0x%llx, vol->mft_zone_end "
687 "0x%llx, mft_zone_size 0x%llx.",
688 (unsigned long long)vol->mft_zone_start,
689 (unsigned long long)vol->mft_zone_end,
690 (unsigned long long)mft_zone_size);
691 if (zone == MFT_ZONE || mft_zone_size <= 0) {
692 ntfs_debug("No free clusters left, going to out.");
693 /* Really no more space left on device. */
694 err = ENOSPC;
695 goto out;
696 } /* zone == DATA_ZONE && mft_zone_size > 0 */
697 ntfs_debug("Shrinking mft zone.");
698 zone_end = vol->mft_zone_end;
699 mft_zone_size >>= 1;
700 if (mft_zone_size > 0)
701 vol->mft_zone_end = vol->mft_zone_start + mft_zone_size;
702 else /* mft zone and data2 zone no longer exist. */
703 vol->data2_zone_pos = vol->mft_zone_start =
704 vol->mft_zone_end = 0;
705 if (vol->mft_zone_pos >= vol->mft_zone_end) {
706 vol->mft_zone_pos = vol->mft_lcn;
707 if (!vol->mft_zone_end)
708 vol->mft_zone_pos = 0;
709 }
710 bmp_pos = zone_start = bmp_initial_pos =
711 vol->data1_zone_pos = vol->mft_zone_end;
712 search_zone = 2;
713 pass = 2;
714 done_zones &= ~2;
715 ntfs_debug("After shrinking mft zone, mft_zone_size 0x%llx, "
716 "vol->mft_zone_start 0x%llx, "
717 "vol->mft_zone_end 0x%llx, "
718 "vol->mft_zone_pos 0x%llx, search_zone 2, "
719 "pass 2, dones_zones 0x%x, zone_start 0x%llx, "
720 "zone_end 0x%llx, vol->data1_zone_pos 0x%llx, "
721 "continuing outer while loop.",
722 (unsigned long long)mft_zone_size,
723 (unsigned long long)vol->mft_zone_start,
724 (unsigned long long)vol->mft_zone_end,
725 (unsigned long long)vol->mft_zone_pos,
726 done_zones, (unsigned long long)zone_start,
727 (unsigned long long)zone_end,
728 (unsigned long long)vol->data1_zone_pos);
729 }
730 ntfs_debug("After outer while loop.");
731out:
732 ntfs_debug("At out.");
733 /* Add runlist terminator element. */
734 if (likely(rl)) {
735 rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
736 rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
737 rl[rlpos].length = 0;
738 }
739 if (likely(page && !IS_ERR(page))) {
740 if (need_writeback) {
741 ntfs_debug("Marking page dirty.");
742 flush_dcache_page(page);
743 set_page_dirty(page);
744 need_writeback = 0;
745 }
746 ntfs_unmap_page(page);
747 }
748 if (likely(!err)) {
749 up_write(&vol->lcnbmp_lock);
750 ntfs_debug("Done.");
751 return rl;
752 }
753 ntfs_error(vol->sb, "Failed to allocate clusters, aborting "
754 "(error %i).", err);
755 if (rl) {
756 int err2;
757
758 if (err == ENOSPC)
759 ntfs_debug("Not enough space to complete allocation, "
760 "err ENOSPC, first free lcn 0x%llx, "
761 "could allocate up to 0x%llx "
762 "clusters.",
763 (unsigned long long)rl[0].lcn,
764 (unsigned long long)count - clusters);
765 /* Deallocate all allocated clusters. */
766 ntfs_debug("Attempting rollback...");
767 err2 = ntfs_cluster_free_from_rl_nolock(vol, rl);
768 if (err2) {
769 ntfs_error(vol->sb, "Failed to rollback (error %i). "
770 "Leaving inconsistent metadata! "
771 "Unmount and run chkdsk.", err2);
772 NVolSetErrors(vol);
773 }
774 /* Free the runlist. */
775 ntfs_free(rl);
776 } else if (err == ENOSPC)
777 ntfs_debug("No space left at all, err = ENOSPC, "
778 "first free lcn = 0x%llx.",
779 (unsigned long long)vol->data1_zone_pos);
780 up_write(&vol->lcnbmp_lock);
781 return ERR_PTR(err);
782}
783
784/**
785 * __ntfs_cluster_free - free clusters on an ntfs volume
786 * @vi: vfs inode whose runlist describes the clusters to free
787 * @start_vcn: vcn in the runlist of @vi at which to start freeing clusters
788 * @count: number of clusters to free or -1 for all clusters
789 * @is_rollback: if TRUE this is a rollback operation
790 *
791 * Free @count clusters starting at the cluster @start_vcn in the runlist
792 * described by the vfs inode @vi.
793 *
794 * If @count is -1, all clusters from @start_vcn to the end of the runlist are
795 * deallocated. Thus, to completely free all clusters in a runlist, use
796 * @start_vcn = 0 and @count = -1.
797 *
798 * @is_rollback should always be FALSE, it is for internal use to rollback
799 * errors. You probably want to use ntfs_cluster_free() instead.
800 *
801 * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
802 * has to deal with it later.
803 *
804 * Return the number of deallocated clusters (not counting sparse ones) on
805 * success and -errno on error.
806 *
807 * Locking: - The runlist described by @vi must be unlocked on entry and is
808 * unlocked on return.
809 * - This function takes the runlist lock of @vi for reading and
810 * sometimes for writing and sometimes modifies the runlist.
811 * - The volume lcn bitmap must be unlocked on entry and is unlocked
812 * on return.
813 * - This function takes the volume lcn bitmap lock for writing and
814 * modifies the bitmap contents.
815 */
816s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count,
817 const BOOL is_rollback)
818{
819 s64 delta, to_free, total_freed, real_freed;
820 ntfs_inode *ni;
821 ntfs_volume *vol;
822 struct inode *lcnbmp_vi;
823 runlist_element *rl;
824 int err;
825
826 BUG_ON(!vi);
827 ntfs_debug("Entering for i_ino 0x%lx, start_vcn 0x%llx, count "
828 "0x%llx.%s", vi->i_ino, (unsigned long long)start_vcn,
829 (unsigned long long)count,
830 is_rollback ? " (rollback)" : "");
831 ni = NTFS_I(vi);
832 vol = ni->vol;
833 lcnbmp_vi = vol->lcnbmp_ino;
834 BUG_ON(!lcnbmp_vi);
835 BUG_ON(start_vcn < 0);
836 BUG_ON(count < -1);
837 /*
838 * Lock the lcn bitmap for writing but only if not rolling back. We
839 * must hold the lock all the way including through rollback otherwise
840 * rollback is not possible because once we have cleared a bit and
841 * dropped the lock, anyone could have set the bit again, thus
842 * allocating the cluster for another use.
843 */
844 if (likely(!is_rollback))
845 down_write(&vol->lcnbmp_lock);
846
847 total_freed = real_freed = 0;
848
849 /* This returns with ni->runlist locked for reading on success. */
850 rl = ntfs_find_vcn(ni, start_vcn, FALSE);
851 if (IS_ERR(rl)) {
852 if (!is_rollback)
853 ntfs_error(vol->sb, "Failed to find first runlist "
854 "element (error %li), aborting.",
855 PTR_ERR(rl));
856 err = PTR_ERR(rl);
857 goto err_out;
858 }
859 if (unlikely(rl->lcn < LCN_HOLE)) {
860 if (!is_rollback)
861 ntfs_error(vol->sb, "First runlist element has "
862 "invalid lcn, aborting.");
863 err = -EIO;
864 goto unl_err_out;
865 }
866 /* Find the starting cluster inside the run that needs freeing. */
867 delta = start_vcn - rl->vcn;
868
869 /* The number of clusters in this run that need freeing. */
870 to_free = rl->length - delta;
871 if (count >= 0 && to_free > count)
872 to_free = count;
873
874 if (likely(rl->lcn >= 0)) {
875 /* Do the actual freeing of the clusters in this run. */
876 err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn + delta,
877 to_free, likely(!is_rollback) ? 0 : 1);
878 if (unlikely(err)) {
879 if (!is_rollback)
880 ntfs_error(vol->sb, "Failed to clear first run "
881 "(error %i), aborting.", err);
882 goto unl_err_out;
883 }
884 /* We have freed @to_free real clusters. */
885 real_freed = to_free;
886 };
887 /* Go to the next run and adjust the number of clusters left to free. */
888 ++rl;
889 if (count >= 0)
890 count -= to_free;
891
892 /* Keep track of the total "freed" clusters, including sparse ones. */
893 total_freed = to_free;
894 /*
895 * Loop over the remaining runs, using @count as a capping value, and
896 * free them.
897 */
898 for (; rl->length && count != 0; ++rl) {
899 if (unlikely(rl->lcn < LCN_HOLE)) {
900 VCN vcn;
901
902 /*
903 * Attempt to map runlist, dropping runlist lock for
904 * the duration.
905 */
906 vcn = rl->vcn;
907 up_read(&ni->runlist.lock);
908 err = ntfs_map_runlist(ni, vcn);
909 if (err) {
910 if (!is_rollback)
911 ntfs_error(vol->sb, "Failed to map "
912 "runlist fragment.");
913 if (err == -EINVAL || err == -ENOENT)
914 err = -EIO;
915 goto err_out;
916 }
917 /*
918 * This returns with ni->runlist locked for reading on
919 * success.
920 */
921 rl = ntfs_find_vcn(ni, vcn, FALSE);
922 if (IS_ERR(rl)) {
923 err = PTR_ERR(rl);
924 if (!is_rollback)
925 ntfs_error(vol->sb, "Failed to find "
926 "subsequent runlist "
927 "element.");
928 goto err_out;
929 }
930 if (unlikely(rl->lcn < LCN_HOLE)) {
931 if (!is_rollback)
932 ntfs_error(vol->sb, "Runlist element "
933 "has invalid lcn "
934 "(0x%llx).",
935 (unsigned long long)
936 rl->lcn);
937 err = -EIO;
938 goto unl_err_out;
939 }
940 }
941 /* The number of clusters in this run that need freeing. */
942 to_free = rl->length;
943 if (count >= 0 && to_free > count)
944 to_free = count;
945
946 if (likely(rl->lcn >= 0)) {
947 /* Do the actual freeing of the clusters in the run. */
948 err = ntfs_bitmap_set_bits_in_run(lcnbmp_vi, rl->lcn,
949 to_free, likely(!is_rollback) ? 0 : 1);
950 if (unlikely(err)) {
951 if (!is_rollback)
952 ntfs_error(vol->sb, "Failed to clear "
953 "subsequent run.");
954 goto unl_err_out;
955 }
956 /* We have freed @to_free real clusters. */
957 real_freed += to_free;
958 }
959 /* Adjust the number of clusters left to free. */
960 if (count >= 0)
961 count -= to_free;
962
963 /* Update the total done clusters. */
964 total_freed += to_free;
965 }
966 up_read(&ni->runlist.lock);
967 if (likely(!is_rollback))
968 up_write(&vol->lcnbmp_lock);
969
970 BUG_ON(count > 0);
971
972 /* We are done. Return the number of actually freed clusters. */
973 ntfs_debug("Done.");
974 return real_freed;
975unl_err_out:
976 up_read(&ni->runlist.lock);
977err_out:
978 if (is_rollback)
979 return err;
980 /* If no real clusters were freed, no need to rollback. */
981 if (!real_freed) {
982 up_write(&vol->lcnbmp_lock);
983 return err;
984 }
985 /*
986 * Attempt to rollback and if that succeeds just return the error code.
987 * If rollback fails, set the volume errors flag, emit an error
988 * message, and return the error code.
989 */
990 delta = __ntfs_cluster_free(vi, start_vcn, total_freed, TRUE);
991 if (delta < 0) {
992 ntfs_error(vol->sb, "Failed to rollback (error %i). Leaving "
993 "inconsistent metadata! Unmount and run "
994 "chkdsk.", (int)delta);
995 NVolSetErrors(vol);
996 }
997 up_write(&vol->lcnbmp_lock);
998 ntfs_error(vol->sb, "Aborting (error %i).", err);
999 return err;
1000}
1001
1002#endif /* NTFS_RW */
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-26 23:06:03 -0500