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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * NTFS kernel journal handling.
4 *
5 * Copyright (c) 2002-2007 Anton Altaparmakov
6 */
7
8#include <linux/blkdev.h>
9
10#include "attrib.h"
11#include "logfile.h"
12#include "ntfs.h"
13
14/*
15 * ntfs_check_restart_page_header - check the page header for consistency
16 * @vi: LogFile inode to which the restart page header belongs
17 * @rp: restart page header to check
18 * @pos: position in @vi at which the restart page header resides
19 *
20 * Check the restart page header @rp for consistency and return 'true' if it is
21 * consistent and 'false' otherwise.
22 *
23 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
24 * require the full restart page.
25 */
26static bool ntfs_check_restart_page_header(struct inode *vi,
27 struct restart_page_header *rp, s64 pos)
28{
29 u32 logfile_system_page_size, logfile_log_page_size;
30 u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
31 bool have_usa = true;
32
33 ntfs_debug("Entering.");
34 /*
35 * If the system or log page sizes are smaller than the ntfs block size
36 * or either is not a power of 2 we cannot handle this log file.
37 */
38 logfile_system_page_size = le32_to_cpu(rp->system_page_size);
39 logfile_log_page_size = le32_to_cpu(rp->log_page_size);
40 if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
41 logfile_log_page_size < NTFS_BLOCK_SIZE ||
42 logfile_system_page_size &
43 (logfile_system_page_size - 1) ||
44 !is_power_of_2(logfile_log_page_size)) {
45 ntfs_error(vi->i_sb, "LogFile uses unsupported page size.");
46 return false;
47 }
48 /*
49 * We must be either at !pos (1st restart page) or at pos = system page
50 * size (2nd restart page).
51 */
52 if (pos && pos != logfile_system_page_size) {
53 ntfs_error(vi->i_sb, "Found restart area in incorrect position in LogFile.");
54 return false;
55 }
56 /* We only know how to handle version 1.1. */
57 if (le16_to_cpu(rp->major_ver) != 1 ||
58 le16_to_cpu(rp->minor_ver) != 1) {
59 ntfs_error(vi->i_sb,
60 "LogFile version %i.%i is not supported. (This driver supports version 1.1 only.)",
61 (int)le16_to_cpu(rp->major_ver),
62 (int)le16_to_cpu(rp->minor_ver));
63 return false;
64 }
65 /*
66 * If chkdsk has been run the restart page may not be protected by an
67 * update sequence array.
68 */
69 if (ntfs_is_chkd_record(rp->magic) && !le16_to_cpu(rp->usa_count)) {
70 have_usa = false;
71 goto skip_usa_checks;
72 }
73 /* Verify the size of the update sequence array. */
74 usa_count = 1 + (logfile_system_page_size >> NTFS_BLOCK_SIZE_BITS);
75 if (usa_count != le16_to_cpu(rp->usa_count)) {
76 ntfs_error(vi->i_sb,
77 "LogFile restart page specifies inconsistent update sequence array count.");
78 return false;
79 }
80 /* Verify the position of the update sequence array. */
81 usa_ofs = le16_to_cpu(rp->usa_ofs);
82 usa_end = usa_ofs + usa_count * sizeof(u16);
83 if (usa_ofs < sizeof(struct restart_page_header) ||
84 usa_end > NTFS_BLOCK_SIZE - sizeof(u16)) {
85 ntfs_error(vi->i_sb,
86 "LogFile restart page specifies inconsistent update sequence array offset.");
87 return false;
88 }
89skip_usa_checks:
90 /*
91 * Verify the position of the restart area. It must be:
92 * - aligned to 8-byte boundary,
93 * - after the update sequence array, and
94 * - within the system page size.
95 */
96 ra_ofs = le16_to_cpu(rp->restart_area_offset);
97 if (ra_ofs & 7 || (have_usa ? ra_ofs < usa_end :
98 ra_ofs < sizeof(struct restart_page_header)) ||
99 ra_ofs > logfile_system_page_size) {
100 ntfs_error(vi->i_sb,
101 "LogFile restart page specifies inconsistent restart area offset.");
102 return false;
103 }
104 /*
105 * Only restart pages modified by chkdsk are allowed to have chkdsk_lsn
106 * set.
107 */
108 if (!ntfs_is_chkd_record(rp->magic) && le64_to_cpu(rp->chkdsk_lsn)) {
109 ntfs_error(vi->i_sb,
110 "LogFile restart page is not modified by chkdsk but a chkdsk LSN is specified.");
111 return false;
112 }
113 ntfs_debug("Done.");
114 return true;
115}
116
117/*
118 * ntfs_check_restart_area - check the restart area for consistency
119 * @vi: LogFile inode to which the restart page belongs
120 * @rp: restart page whose restart area to check
121 *
122 * Check the restart area of the restart page @rp for consistency and return
123 * 'true' if it is consistent and 'false' otherwise.
124 *
125 * This function assumes that the restart page header has already been
126 * consistency checked.
127 *
128 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
129 * require the full restart page.
130 */
131static bool ntfs_check_restart_area(struct inode *vi, struct restart_page_header *rp)
132{
133 u64 file_size;
134 struct restart_area *ra;
135 u32 ra_ofs, ra_len, ca_ofs;
136 u8 fs_bits;
137
138 ntfs_debug("Entering.");
139 ra_ofs = le16_to_cpu(rp->restart_area_offset);
140 ra = (struct restart_area *)((u8 *)rp + ra_ofs);
141 /*
142 * Everything before ra->file_size must be before the first word
143 * protected by an update sequence number. This ensures that it is
144 * safe to access ra->client_array_offset.
145 */
146 if (ra_ofs + offsetof(struct restart_area, file_size) >
147 NTFS_BLOCK_SIZE - sizeof(u16)) {
148 ntfs_error(vi->i_sb,
149 "LogFile restart area specifies inconsistent file offset.");
150 return false;
151 }
152 /*
153 * Now that we can access ra->client_array_offset, make sure everything
154 * up to the log client array is before the first word protected by an
155 * update sequence number. This ensures we can access all of the
156 * restart area elements safely. Also, the client array offset must be
157 * aligned to an 8-byte boundary.
158 */
159 ca_ofs = le16_to_cpu(ra->client_array_offset);
160 if (((ca_ofs + 7) & ~7) != ca_ofs ||
161 ra_ofs + ca_ofs > NTFS_BLOCK_SIZE - sizeof(u16)) {
162 ntfs_error(vi->i_sb,
163 "LogFile restart area specifies inconsistent client array offset.");
164 return false;
165 }
166 /*
167 * The restart area must end within the system page size both when
168 * calculated manually and as specified by ra->restart_area_length.
169 * Also, the calculated length must not exceed the specified length.
170 */
171 ra_len = ca_ofs + le16_to_cpu(ra->log_clients) *
172 sizeof(struct log_client_record);
173 if (ra_ofs + ra_len > le32_to_cpu(rp->system_page_size) ||
174 ra_ofs + le16_to_cpu(ra->restart_area_length) >
175 le32_to_cpu(rp->system_page_size) ||
176 ra_len > le16_to_cpu(ra->restart_area_length)) {
177 ntfs_error(vi->i_sb,
178 "LogFile restart area is out of bounds of the system page size specified by the restart page header and/or the specified restart area length is inconsistent.");
179 return false;
180 }
181 /*
182 * The ra->client_free_list and ra->client_in_use_list must be either
183 * LOGFILE_NO_CLIENT or less than ra->log_clients or they are
184 * overflowing the client array.
185 */
186 if ((ra->client_free_list != LOGFILE_NO_CLIENT &&
187 le16_to_cpu(ra->client_free_list) >=
188 le16_to_cpu(ra->log_clients)) ||
189 (ra->client_in_use_list != LOGFILE_NO_CLIENT &&
190 le16_to_cpu(ra->client_in_use_list) >=
191 le16_to_cpu(ra->log_clients))) {
192 ntfs_error(vi->i_sb,
193 "LogFile restart area specifies overflowing client free and/or in use lists.");
194 return false;
195 }
196 /*
197 * Check ra->seq_number_bits against ra->file_size for consistency.
198 * We cannot just use ffs() because the file size is not a power of 2.
199 */
200 file_size = le64_to_cpu(ra->file_size);
201 fs_bits = 0;
202 while (file_size) {
203 file_size >>= 1;
204 fs_bits++;
205 }
206 if (le32_to_cpu(ra->seq_number_bits) != 67 - fs_bits) {
207 ntfs_error(vi->i_sb,
208 "LogFile restart area specifies inconsistent sequence number bits.");
209 return false;
210 }
211 /* The log record header length must be a multiple of 8. */
212 if (((le16_to_cpu(ra->log_record_header_length) + 7) & ~7) !=
213 le16_to_cpu(ra->log_record_header_length)) {
214 ntfs_error(vi->i_sb,
215 "LogFile restart area specifies inconsistent log record header length.");
216 return false;
217 }
218 /* Dito for the log page data offset. */
219 if (((le16_to_cpu(ra->log_page_data_offset) + 7) & ~7) !=
220 le16_to_cpu(ra->log_page_data_offset)) {
221 ntfs_error(vi->i_sb,
222 "LogFile restart area specifies inconsistent log page data offset.");
223 return false;
224 }
225 ntfs_debug("Done.");
226 return true;
227}
228
229/*
230 * ntfs_check_log_client_array - check the log client array for consistency
231 * @vi: LogFile inode to which the restart page belongs
232 * @rp: restart page whose log client array to check
233 *
234 * Check the log client array of the restart page @rp for consistency and
235 * return 'true' if it is consistent and 'false' otherwise.
236 *
237 * This function assumes that the restart page header and the restart area have
238 * already been consistency checked.
239 *
240 * Unlike ntfs_check_restart_page_header() and ntfs_check_restart_area(), this
241 * function needs @rp->system_page_size bytes in @rp, i.e. it requires the full
242 * restart page and the page must be multi sector transfer deprotected.
243 */
244static bool ntfs_check_log_client_array(struct inode *vi,
245 struct restart_page_header *rp)
246{
247 struct restart_area *ra;
248 struct log_client_record *ca, *cr;
249 u16 nr_clients, idx;
250 bool in_free_list, idx_is_first;
251
252 ntfs_debug("Entering.");
253 ra = (struct restart_area *)((u8 *)rp + le16_to_cpu(rp->restart_area_offset));
254 ca = (struct log_client_record *)((u8 *)ra +
255 le16_to_cpu(ra->client_array_offset));
256 /*
257 * Check the ra->client_free_list first and then check the
258 * ra->client_in_use_list. Check each of the log client records in
259 * each of the lists and check that the array does not overflow the
260 * ra->log_clients value. Also keep track of the number of records
261 * visited as there cannot be more than ra->log_clients records and
262 * that way we detect eventual loops in within a list.
263 */
264 nr_clients = le16_to_cpu(ra->log_clients);
265 idx = le16_to_cpu(ra->client_free_list);
266 in_free_list = true;
267check_list:
268 for (idx_is_first = true; idx != LOGFILE_NO_CLIENT_CPU; nr_clients--,
269 idx = le16_to_cpu(cr->next_client)) {
270 if (!nr_clients || idx >= le16_to_cpu(ra->log_clients))
271 goto err_out;
272 /* Set @cr to the current log client record. */
273 cr = ca + idx;
274 /* The first log client record must not have a prev_client. */
275 if (idx_is_first) {
276 if (cr->prev_client != LOGFILE_NO_CLIENT)
277 goto err_out;
278 idx_is_first = false;
279 }
280 }
281 /* Switch to and check the in use list if we just did the free list. */
282 if (in_free_list) {
283 in_free_list = false;
284 idx = le16_to_cpu(ra->client_in_use_list);
285 goto check_list;
286 }
287 ntfs_debug("Done.");
288 return true;
289err_out:
290 ntfs_error(vi->i_sb, "LogFile log client array is corrupt.");
291 return false;
292}
293
294/*
295 * ntfs_check_and_load_restart_page - check the restart page for consistency
296 * @vi: LogFile inode to which the restart page belongs
297 * @rp: restart page to check
298 * @pos: position in @vi at which the restart page resides
299 * @wrp: [OUT] copy of the multi sector transfer deprotected restart page
300 * @lsn: [OUT] set to the current logfile lsn on success
301 *
302 * Check the restart page @rp for consistency and return 0 if it is consistent
303 * and -errno otherwise. The restart page may have been modified by chkdsk in
304 * which case its magic is CHKD instead of RSTR.
305 *
306 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
307 * require the full restart page.
308 *
309 * If @wrp is not NULL, on success, *@wrp will point to a buffer containing a
310 * copy of the complete multi sector transfer deprotected page. On failure,
311 * *@wrp is undefined.
312 *
313 * Simillarly, if @lsn is not NULL, on success *@lsn will be set to the current
314 * logfile lsn according to this restart page. On failure, *@lsn is undefined.
315 *
316 * The following error codes are defined:
317 * -EINVAL - The restart page is inconsistent.
318 * -ENOMEM - Not enough memory to load the restart page.
319 * -EIO - Failed to reading from LogFile.
320 */
321static int ntfs_check_and_load_restart_page(struct inode *vi,
322 struct restart_page_header *rp, s64 pos, struct restart_page_header **wrp,
323 s64 *lsn)
324{
325 struct restart_area *ra;
326 struct restart_page_header *trp;
327 int size, err;
328
329 ntfs_debug("Entering.");
330 /* Check the restart page header for consistency. */
331 if (!ntfs_check_restart_page_header(vi, rp, pos)) {
332 /* Error output already done inside the function. */
333 return -EINVAL;
334 }
335 /* Check the restart area for consistency. */
336 if (!ntfs_check_restart_area(vi, rp)) {
337 /* Error output already done inside the function. */
338 return -EINVAL;
339 }
340 ra = (struct restart_area *)((u8 *)rp + le16_to_cpu(rp->restart_area_offset));
341 /*
342 * Allocate a buffer to store the whole restart page so we can multi
343 * sector transfer deprotect it.
344 */
345 trp = kvzalloc(le32_to_cpu(rp->system_page_size), GFP_NOFS);
346 if (!trp) {
347 ntfs_error(vi->i_sb, "Failed to allocate memory for LogFile restart page buffer.");
348 return -ENOMEM;
349 }
350 /*
351 * Read the whole of the restart page into the buffer. If it fits
352 * completely inside @rp, just copy it from there. Otherwise map all
353 * the required pages and copy the data from them.
354 */
355 size = PAGE_SIZE - (pos & ~PAGE_MASK);
356 if (size >= le32_to_cpu(rp->system_page_size)) {
357 memcpy(trp, rp, le32_to_cpu(rp->system_page_size));
358 } else {
359 pgoff_t idx;
360 struct folio *folio;
361 int have_read, to_read;
362
363 /* First copy what we already have in @rp. */
364 memcpy(trp, rp, size);
365 /* Copy the remaining data one page at a time. */
366 have_read = size;
367 to_read = le32_to_cpu(rp->system_page_size) - size;
368 idx = (pos + size) >> PAGE_SHIFT;
369 do {
370 folio = read_mapping_folio(vi->i_mapping, idx, NULL);
371 if (IS_ERR(folio)) {
372 ntfs_error(vi->i_sb, "Error mapping LogFile page (index %lu).",
373 idx);
374 err = PTR_ERR(folio);
375 if (err != -EIO && err != -ENOMEM)
376 err = -EIO;
377 goto err_out;
378 }
379 size = min_t(int, to_read, PAGE_SIZE);
380 memcpy((u8 *)trp + have_read, folio_address(folio), size);
381 folio_put(folio);
382 have_read += size;
383 to_read -= size;
384 idx++;
385 } while (to_read > 0);
386 }
387 /*
388 * Perform the multi sector transfer deprotection on the buffer if the
389 * restart page is protected.
390 */
391 if ((!ntfs_is_chkd_record(trp->magic) || le16_to_cpu(trp->usa_count)) &&
392 post_read_mst_fixup((struct ntfs_record *)trp, le32_to_cpu(rp->system_page_size))) {
393 /*
394 * A multi sector transfer error was detected. We only need to
395 * abort if the restart page contents exceed the multi sector
396 * transfer fixup of the first sector.
397 */
398 if (le16_to_cpu(rp->restart_area_offset) +
399 le16_to_cpu(ra->restart_area_length) >
400 NTFS_BLOCK_SIZE - sizeof(u16)) {
401 ntfs_error(vi->i_sb,
402 "Multi sector transfer error detected in LogFile restart page.");
403 err = -EINVAL;
404 goto err_out;
405 }
406 }
407 /*
408 * If the restart page is modified by chkdsk or there are no active
409 * logfile clients, the logfile is consistent. Otherwise, need to
410 * check the log client records for consistency, too.
411 */
412 err = 0;
413 if (ntfs_is_rstr_record(rp->magic) &&
414 ra->client_in_use_list != LOGFILE_NO_CLIENT) {
415 if (!ntfs_check_log_client_array(vi, trp)) {
416 err = -EINVAL;
417 goto err_out;
418 }
419 }
420 if (lsn) {
421 if (ntfs_is_rstr_record(rp->magic))
422 *lsn = le64_to_cpu(ra->current_lsn);
423 else /* if (ntfs_is_chkd_record(rp->magic)) */
424 *lsn = le64_to_cpu(rp->chkdsk_lsn);
425 }
426 ntfs_debug("Done.");
427 if (wrp)
428 *wrp = trp;
429 else {
430err_out:
431 kvfree(trp);
432 }
433 return err;
434}
435
436/*
437 * ntfs_check_logfile - check the journal for consistency
438 * @log_vi: struct inode of loaded journal LogFile to check
439 * @rp: [OUT] on success this is a copy of the current restart page
440 *
441 * Check the LogFile journal for consistency and return 'true' if it is
442 * consistent and 'false' if not. On success, the current restart page is
443 * returned in *@rp. Caller must call kvfree(*@rp) when finished with it.
444 *
445 * At present we only check the two restart pages and ignore the log record
446 * pages.
447 *
448 * Note that the MstProtected flag is not set on the LogFile inode and hence
449 * when reading pages they are not deprotected. This is because we do not know
450 * if the LogFile was created on a system with a different page size to ours
451 * yet and mst deprotection would fail if our page size is smaller.
452 */
453bool ntfs_check_logfile(struct inode *log_vi, struct restart_page_header **rp)
454{
455 s64 size, pos;
456 s64 rstr1_lsn, rstr2_lsn;
457 struct ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
458 struct address_space *mapping = log_vi->i_mapping;
459 struct folio *folio = NULL;
460 u8 *kaddr = NULL;
461 struct restart_page_header *rstr1_ph = NULL;
462 struct restart_page_header *rstr2_ph = NULL;
463 int log_page_size, err;
464 bool logfile_is_empty = true;
465 u8 log_page_bits;
466
467 ntfs_debug("Entering.");
468 /* An empty LogFile must have been clean before it got emptied. */
469 if (NVolLogFileEmpty(vol))
470 goto is_empty;
471 size = i_size_read(log_vi);
472 /* Make sure the file doesn't exceed the maximum allowed size. */
473 if (size > MaxLogFileSize)
474 size = MaxLogFileSize;
475 /*
476 * Truncate size to a multiple of the page cache size or the default
477 * log page size if the page cache size is between the default log page
478 * log page size if the page cache size is between the default log page
479 * size and twice that.
480 */
481 if (DefaultLogPageSize <= PAGE_SIZE &&
482 DefaultLogPageSize * 2 <= PAGE_SIZE)
483 log_page_size = DefaultLogPageSize;
484 else
485 log_page_size = PAGE_SIZE;
486 /*
487 * Use ntfs_ffs() instead of ffs() to enable the compiler to
488 * optimize log_page_size and log_page_bits into constants.
489 */
490 log_page_bits = ntfs_ffs(log_page_size) - 1;
491 size &= ~(s64)(log_page_size - 1);
492 /*
493 * Ensure the log file is big enough to store at least the two restart
494 * pages and the minimum number of log record pages.
495 */
496 if (size < log_page_size * 2 || (size - log_page_size * 2) >>
497 log_page_bits < MinLogRecordPages) {
498 ntfs_error(vol->sb, "LogFile is too small.");
499 return false;
500 }
501 /*
502 * Read through the file looking for a restart page. Since the restart
503 * page header is at the beginning of a page we only need to search at
504 * what could be the beginning of a page (for each page size) rather
505 * than scanning the whole file byte by byte. If all potential places
506 * contain empty and uninitialzed records, the log file can be assumed
507 * to be empty.
508 */
509 for (pos = 0; pos < size; pos <<= 1) {
510 pgoff_t idx = pos >> PAGE_SHIFT;
511
512 if (!folio || folio->index != idx) {
513 if (folio) {
514 kunmap_local(kaddr);
515 folio_put(folio);
516 }
517 folio = read_mapping_folio(mapping, idx, NULL);
518 if (IS_ERR(folio)) {
519 ntfs_error(vol->sb, "Error mapping LogFile page (index %lu).",
520 idx);
521 goto err_out;
522 }
523 }
524 kaddr = (u8 *)kmap_local_folio(folio, 0) + (pos & ~PAGE_MASK);
525 /*
526 * A non-empty block means the logfile is not empty while an
527 * empty block after a non-empty block has been encountered
528 * means we are done.
529 */
530 if (!ntfs_is_empty_recordp((__le32 *)kaddr))
531 logfile_is_empty = false;
532 else if (!logfile_is_empty)
533 break;
534 /*
535 * A log record page means there cannot be a restart page after
536 * this so no need to continue searching.
537 */
538 if (ntfs_is_rcrd_recordp((__le32 *)kaddr))
539 break;
540 /* If not a (modified by chkdsk) restart page, continue. */
541 if (!ntfs_is_rstr_recordp((__le32 *)kaddr) &&
542 !ntfs_is_chkd_recordp((__le32 *)kaddr)) {
543 if (!pos)
544 pos = NTFS_BLOCK_SIZE >> 1;
545 continue;
546 }
547 /*
548 * Check the (modified by chkdsk) restart page for consistency
549 * and get a copy of the complete multi sector transfer
550 * deprotected restart page.
551 */
552 err = ntfs_check_and_load_restart_page(log_vi,
553 (struct restart_page_header *)kaddr, pos,
554 !rstr1_ph ? &rstr1_ph : &rstr2_ph,
555 !rstr1_ph ? &rstr1_lsn : &rstr2_lsn);
556 if (!err) {
557 /*
558 * If we have now found the first (modified by chkdsk)
559 * restart page, continue looking for the second one.
560 */
561 if (!pos) {
562 pos = NTFS_BLOCK_SIZE >> 1;
563 continue;
564 }
565 /*
566 * We have now found the second (modified by chkdsk)
567 * restart page, so we can stop looking.
568 */
569 break;
570 }
571 /*
572 * Error output already done inside the function. Note, we do
573 * not abort if the restart page was invalid as we might still
574 * find a valid one further in the file.
575 */
576 if (err != -EINVAL) {
577 kunmap_local(kaddr);
578 folio_put(folio);
579 goto err_out;
580 }
581 /* Continue looking. */
582 if (!pos)
583 pos = NTFS_BLOCK_SIZE >> 1;
584 }
585 if (folio) {
586 kunmap_local(kaddr);
587 folio_put(folio);
588 }
589 if (logfile_is_empty) {
590 NVolSetLogFileEmpty(vol);
591is_empty:
592 ntfs_debug("Done. (LogFile is empty.)");
593 return true;
594 }
595 if (!rstr1_ph) {
596 ntfs_error(vol->sb,
597 "Did not find any restart pages in LogFile and it was not empty.");
598 return false;
599 }
600 /* If both restart pages were found, use the more recent one. */
601 if (rstr2_ph) {
602 /*
603 * If the second restart area is more recent, switch to it.
604 * Otherwise just throw it away.
605 */
606 if (rstr2_lsn > rstr1_lsn) {
607 ntfs_debug("Using second restart page as it is more recent.");
608 kvfree(rstr1_ph);
609 rstr1_ph = rstr2_ph;
610 /* rstr1_lsn = rstr2_lsn; */
611 } else {
612 ntfs_debug("Using first restart page as it is more recent.");
613 kvfree(rstr2_ph);
614 }
615 rstr2_ph = NULL;
616 }
617 /* All consistency checks passed. */
618 if (rp)
619 *rp = rstr1_ph;
620 else
621 kvfree(rstr1_ph);
622 ntfs_debug("Done.");
623 return true;
624err_out:
625 kvfree(rstr1_ph);
626 return false;
627}
628
629/*
630 * ntfs_empty_logfile - empty the contents of the LogFile journal
631 * @log_vi: struct inode of loaded journal LogFile to empty
632 *
633 * Empty the contents of the LogFile journal @log_vi and return 'true' on
634 * success and 'false' on error.
635 *
636 * This function assumes that the LogFile journal has already been consistency
637 * checked by a call to ntfs_check_logfile() and that ntfs_is_logfile_clean()
638 * has been used to ensure that the LogFile is clean.
639 */
640bool ntfs_empty_logfile(struct inode *log_vi)
641{
642 s64 vcn, end_vcn;
643 struct ntfs_inode *log_ni = NTFS_I(log_vi);
644 struct ntfs_volume *vol = log_ni->vol;
645 struct super_block *sb = vol->sb;
646 struct runlist_element *rl;
647 unsigned long flags;
648 int err;
649 bool should_wait = true;
650 char *empty_buf = NULL;
651 struct file_ra_state *ra = NULL;
652
653 ntfs_debug("Entering.");
654 if (NVolLogFileEmpty(vol)) {
655 ntfs_debug("Done.");
656 return true;
657 }
658
659 /*
660 * We cannot use ntfs_attr_set() because we may be still in the middle
661 * of a mount operation. Thus we do the emptying by hand by first
662 * zapping the page cache pages for the LogFile/DATA attribute and
663 * then emptying each of the buffers in each of the clusters specified
664 * by the runlist by hand.
665 */
666 vcn = 0;
667 read_lock_irqsave(&log_ni->size_lock, flags);
668 end_vcn = (log_ni->initialized_size + vol->cluster_size_mask) >>
669 vol->cluster_size_bits;
670 read_unlock_irqrestore(&log_ni->size_lock, flags);
671 truncate_inode_pages(log_vi->i_mapping, 0);
672 down_write(&log_ni->runlist.lock);
673 rl = log_ni->runlist.rl;
674 if (unlikely(!rl || vcn < rl->vcn || !rl->length)) {
675map_vcn:
676 err = ntfs_map_runlist_nolock(log_ni, vcn, NULL);
677 if (err) {
678 ntfs_error(sb, "Failed to map runlist fragment (error %d).", -err);
679 goto err;
680 }
681 rl = log_ni->runlist.rl;
682 }
683 /* Seek to the runlist element containing @vcn. */
684 while (rl->length && vcn >= rl[1].vcn)
685 rl++;
686
687 err = -ENOMEM;
688 empty_buf = kvzalloc(vol->cluster_size, GFP_NOFS);
689 if (!empty_buf)
690 goto err;
691
692 memset(empty_buf, 0xff, vol->cluster_size);
693
694 ra = kzalloc_obj(*ra, GFP_NOFS);
695 if (!ra)
696 goto err;
697
698 file_ra_state_init(ra, sb->s_bdev->bd_mapping);
699 do {
700 s64 lcn;
701 loff_t start, end;
702 s64 len;
703
704 /*
705 * If this run is not mapped map it now and start again as the
706 * runlist will have been updated.
707 */
708 lcn = rl->lcn;
709 if (unlikely(lcn == LCN_RL_NOT_MAPPED)) {
710 vcn = rl->vcn;
711 kvfree(empty_buf);
712 empty_buf = NULL;
713 kfree(ra);
714 ra = NULL;
715 goto map_vcn;
716 }
717 /* If this run is not valid abort with an error. */
718 if (unlikely(!rl->length || lcn < LCN_HOLE))
719 goto rl_err;
720 /* Skip holes. */
721 if (lcn == LCN_HOLE)
722 continue;
723 start = NTFS_CLU_TO_B(vol, lcn);
724 len = rl->length;
725 if (rl[1].vcn > end_vcn)
726 len = end_vcn - rl->vcn;
727 end = NTFS_CLU_TO_B(vol, lcn + len);
728
729 page_cache_sync_readahead(sb->s_bdev->bd_mapping, ra, NULL,
730 start >> PAGE_SHIFT, (end - start) >> PAGE_SHIFT);
731
732 do {
733 err = ntfs_bdev_write(sb, empty_buf, start,
734 vol->cluster_size);
735 if (err) {
736 ntfs_error(sb, "ntfs_dev_write failed, err : %d\n", err);
737 goto io_err;
738 }
739
740 /*
741 * Submit the buffer and wait for i/o to complete but
742 * only for the first buffer so we do not miss really
743 * serious i/o errors. Once the first buffer has
744 * completed ignore errors afterwards as we can assume
745 * that if one buffer worked all of them will work.
746 */
747 if (should_wait) {
748 should_wait = false;
749 err = filemap_write_and_wait_range(sb->s_bdev->bd_mapping,
750 start, start + vol->cluster_size);
751 if (err)
752 goto io_err;
753 }
754 start += vol->cluster_size;
755 } while (start < end);
756 } while ((++rl)->vcn < end_vcn);
757 up_write(&log_ni->runlist.lock);
758 kvfree(empty_buf);
759 kfree(ra);
760 truncate_inode_pages(log_vi->i_mapping, 0);
761 /* Set the flag so we do not have to do it again on remount. */
762 NVolSetLogFileEmpty(vol);
763 ntfs_debug("Done.");
764 return true;
765io_err:
766 ntfs_error(sb, "Failed to write buffer. Unmount and run chkdsk.");
767 goto dirty_err;
768rl_err:
769 ntfs_error(sb, "Runlist is corrupt. Unmount and run chkdsk.");
770dirty_err:
771 NVolSetErrors(vol);
772 err = -EIO;
773err:
774 kvfree(empty_buf);
775 kfree(ra);
776 up_write(&log_ni->runlist.lock);
777 ntfs_error(sb, "Failed to fill LogFile with 0xff bytes (error %d).",
778 -err);
779 return false;
780}