1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * logfile.c - NTFS kernel journal handling. Part of the Linux-NTFS project.
4 *
5 * Copyright (c) 2002-2007 Anton Altaparmakov
6 */
7
8#ifdef NTFS_RW
9
10#include <linux/types.h>
11#include <linux/fs.h>
12#include <linux/highmem.h>
13#include <linux/buffer_head.h>
14#include <linux/bitops.h>
15#include <linux/log2.h>
16#include <linux/bio.h>
17
18#include "attrib.h"
19#include "aops.h"
20#include "debug.h"
21#include "logfile.h"
22#include "malloc.h"
23#include "volume.h"
24#include "ntfs.h"
25
26/**
27 * ntfs_check_restart_page_header - check the page header for consistency
28 * @vi: $LogFile inode to which the restart page header belongs
29 * @rp: restart page header to check
30 * @pos: position in @vi at which the restart page header resides
31 *
32 * Check the restart page header @rp for consistency and return 'true' if it is
33 * consistent and 'false' otherwise.
34 *
35 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
36 * require the full restart page.
37 */
38static bool ntfs_check_restart_page_header(struct inode *vi,
39 RESTART_PAGE_HEADER *rp, s64 pos)
40{
41 u32 logfile_system_page_size, logfile_log_page_size;
42 u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
43 bool have_usa = true;
44
45 ntfs_debug("Entering.");
46 /*
47 * If the system or log page sizes are smaller than the ntfs block size
48 * or either is not a power of 2 we cannot handle this log file.
49 */
50 logfile_system_page_size = le32_to_cpu(rp->system_page_size);
51 logfile_log_page_size = le32_to_cpu(rp->log_page_size);
52 if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
53 logfile_log_page_size < NTFS_BLOCK_SIZE ||
54 logfile_system_page_size &
55 (logfile_system_page_size - 1) ||
56 !is_power_of_2(logfile_log_page_size)) {
57 ntfs_error(vi->i_sb, "$LogFile uses unsupported page size.");
58 return false;
59 }
60 /*
61 * We must be either at !pos (1st restart page) or at pos = system page
62 * size (2nd restart page).
63 */
64 if (pos && pos != logfile_system_page_size) {
65 ntfs_error(vi->i_sb, "Found restart area in incorrect "
66 "position in $LogFile.");
67 return false;
68 }
69 /* We only know how to handle version 1.1. */
70 if (sle16_to_cpu(rp->major_ver) != 1 ||
71 sle16_to_cpu(rp->minor_ver) != 1) {
72 ntfs_error(vi->i_sb, "$LogFile version %i.%i is not "
73 "supported. (This driver supports version "
74 "1.1 only.)", (int)sle16_to_cpu(rp->major_ver),
75 (int)sle16_to_cpu(rp->minor_ver));
76 return false;
77 }
78 /*
79 * If chkdsk has been run the restart page may not be protected by an
80 * update sequence array.
81 */
82 if (ntfs_is_chkd_record(rp->magic) && !le16_to_cpu(rp->usa_count)) {
83 have_usa = false;
84 goto skip_usa_checks;
85 }
86 /* Verify the size of the update sequence array. */
87 usa_count = 1 + (logfile_system_page_size >> NTFS_BLOCK_SIZE_BITS);
88 if (usa_count != le16_to_cpu(rp->usa_count)) {
89 ntfs_error(vi->i_sb, "$LogFile restart page specifies "
90 "inconsistent update sequence array count.");
91 return false;
92 }
93 /* Verify the position of the update sequence array. */
94 usa_ofs = le16_to_cpu(rp->usa_ofs);
95 usa_end = usa_ofs + usa_count * sizeof(u16);
96 if (usa_ofs < sizeof(RESTART_PAGE_HEADER) ||
97 usa_end > NTFS_BLOCK_SIZE - sizeof(u16)) {
98 ntfs_error(vi->i_sb, "$LogFile restart page specifies "
99 "inconsistent update sequence array offset.");
100 return false;
101 }
102skip_usa_checks:
103 /*
104 * Verify the position of the restart area. It must be:
105 * - aligned to 8-byte boundary,
106 * - after the update sequence array, and
107 * - within the system page size.
108 */
109 ra_ofs = le16_to_cpu(rp->restart_area_offset);
110 if (ra_ofs & 7 || (have_usa ? ra_ofs < usa_end :
111 ra_ofs < sizeof(RESTART_PAGE_HEADER)) ||
112 ra_ofs > logfile_system_page_size) {
113 ntfs_error(vi->i_sb, "$LogFile restart page specifies "
114 "inconsistent restart area offset.");
115 return false;
116 }
117 /*
118 * Only restart pages modified by chkdsk are allowed to have chkdsk_lsn
119 * set.
120 */
121 if (!ntfs_is_chkd_record(rp->magic) && sle64_to_cpu(rp->chkdsk_lsn)) {
122 ntfs_error(vi->i_sb, "$LogFile restart page is not modified "
123 "by chkdsk but a chkdsk LSN is specified.");
124 return false;
125 }
126 ntfs_debug("Done.");
127 return true;
128}
129
130/**
131 * ntfs_check_restart_area - check the restart area for consistency
132 * @vi: $LogFile inode to which the restart page belongs
133 * @rp: restart page whose restart area to check
134 *
135 * Check the restart area of the restart page @rp for consistency and return
136 * 'true' if it is consistent and 'false' otherwise.
137 *
138 * This function assumes that the restart page header has already been
139 * consistency checked.
140 *
141 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
142 * require the full restart page.
143 */
144static bool ntfs_check_restart_area(struct inode *vi, RESTART_PAGE_HEADER *rp)
145{
146 u64 file_size;
147 RESTART_AREA *ra;
148 u16 ra_ofs, ra_len, ca_ofs;
149 u8 fs_bits;
150
151 ntfs_debug("Entering.");
152 ra_ofs = le16_to_cpu(rp->restart_area_offset);
153 ra = (RESTART_AREA*)((u8*)rp + ra_ofs);
154 /*
155 * Everything before ra->file_size must be before the first word
156 * protected by an update sequence number. This ensures that it is
157 * safe to access ra->client_array_offset.
158 */
159 if (ra_ofs + offsetof(RESTART_AREA, file_size) >
160 NTFS_BLOCK_SIZE - sizeof(u16)) {
161 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
162 "inconsistent file offset.");
163 return false;
164 }
165 /*
166 * Now that we can access ra->client_array_offset, make sure everything
167 * up to the log client array is before the first word protected by an
168 * update sequence number. This ensures we can access all of the
169 * restart area elements safely. Also, the client array offset must be
170 * aligned to an 8-byte boundary.
171 */
172 ca_ofs = le16_to_cpu(ra->client_array_offset);
173 if (((ca_ofs + 7) & ~7) != ca_ofs ||
174 ra_ofs + ca_ofs > NTFS_BLOCK_SIZE - sizeof(u16)) {
175 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
176 "inconsistent client array offset.");
177 return false;
178 }
179 /*
180 * The restart area must end within the system page size both when
181 * calculated manually and as specified by ra->restart_area_length.
182 * Also, the calculated length must not exceed the specified length.
183 */
184 ra_len = ca_ofs + le16_to_cpu(ra->log_clients) *
185 sizeof(LOG_CLIENT_RECORD);
186 if (ra_ofs + ra_len > le32_to_cpu(rp->system_page_size) ||
187 ra_ofs + le16_to_cpu(ra->restart_area_length) >
188 le32_to_cpu(rp->system_page_size) ||
189 ra_len > le16_to_cpu(ra->restart_area_length)) {
190 ntfs_error(vi->i_sb, "$LogFile restart area is out of bounds "
191 "of the system page size specified by the "
192 "restart page header and/or the specified "
193 "restart area length is inconsistent.");
194 return false;
195 }
196 /*
197 * The ra->client_free_list and ra->client_in_use_list must be either
198 * LOGFILE_NO_CLIENT or less than ra->log_clients or they are
199 * overflowing the client array.
200 */
201 if ((ra->client_free_list != LOGFILE_NO_CLIENT &&
202 le16_to_cpu(ra->client_free_list) >=
203 le16_to_cpu(ra->log_clients)) ||
204 (ra->client_in_use_list != LOGFILE_NO_CLIENT &&
205 le16_to_cpu(ra->client_in_use_list) >=
206 le16_to_cpu(ra->log_clients))) {
207 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
208 "overflowing client free and/or in use lists.");
209 return false;
210 }
211 /*
212 * Check ra->seq_number_bits against ra->file_size for consistency.
213 * We cannot just use ffs() because the file size is not a power of 2.
214 */
215 file_size = (u64)sle64_to_cpu(ra->file_size);
216 fs_bits = 0;
217 while (file_size) {
218 file_size >>= 1;
219 fs_bits++;
220 }
221 if (le32_to_cpu(ra->seq_number_bits) != 67 - fs_bits) {
222 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
223 "inconsistent sequence number bits.");
224 return false;
225 }
226 /* The log record header length must be a multiple of 8. */
227 if (((le16_to_cpu(ra->log_record_header_length) + 7) & ~7) !=
228 le16_to_cpu(ra->log_record_header_length)) {
229 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
230 "inconsistent log record header length.");
231 return false;
232 }
233 /* Dito for the log page data offset. */
234 if (((le16_to_cpu(ra->log_page_data_offset) + 7) & ~7) !=
235 le16_to_cpu(ra->log_page_data_offset)) {
236 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
237 "inconsistent log page data offset.");
238 return false;
239 }
240 ntfs_debug("Done.");
241 return true;
242}
243
244/**
245 * ntfs_check_log_client_array - check the log client array for consistency
246 * @vi: $LogFile inode to which the restart page belongs
247 * @rp: restart page whose log client array to check
248 *
249 * Check the log client array of the restart page @rp for consistency and
250 * return 'true' if it is consistent and 'false' otherwise.
251 *
252 * This function assumes that the restart page header and the restart area have
253 * already been consistency checked.
254 *
255 * Unlike ntfs_check_restart_page_header() and ntfs_check_restart_area(), this
256 * function needs @rp->system_page_size bytes in @rp, i.e. it requires the full
257 * restart page and the page must be multi sector transfer deprotected.
258 */
259static bool ntfs_check_log_client_array(struct inode *vi,
260 RESTART_PAGE_HEADER *rp)
261{
262 RESTART_AREA *ra;
263 LOG_CLIENT_RECORD *ca, *cr;
264 u16 nr_clients, idx;
265 bool in_free_list, idx_is_first;
266
267 ntfs_debug("Entering.");
268 ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
269 ca = (LOG_CLIENT_RECORD*)((u8*)ra +
270 le16_to_cpu(ra->client_array_offset));
271 /*
272 * Check the ra->client_free_list first and then check the
273 * ra->client_in_use_list. Check each of the log client records in
274 * each of the lists and check that the array does not overflow the
275 * ra->log_clients value. Also keep track of the number of records
276 * visited as there cannot be more than ra->log_clients records and
277 * that way we detect eventual loops in within a list.
278 */
279 nr_clients = le16_to_cpu(ra->log_clients);
280 idx = le16_to_cpu(ra->client_free_list);
281 in_free_list = true;
282check_list:
283 for (idx_is_first = true; idx != LOGFILE_NO_CLIENT_CPU; nr_clients--,
284 idx = le16_to_cpu(cr->next_client)) {
285 if (!nr_clients || idx >= le16_to_cpu(ra->log_clients))
286 goto err_out;
287 /* Set @cr to the current log client record. */
288 cr = ca + idx;
289 /* The first log client record must not have a prev_client. */
290 if (idx_is_first) {
291 if (cr->prev_client != LOGFILE_NO_CLIENT)
292 goto err_out;
293 idx_is_first = false;
294 }
295 }
296 /* Switch to and check the in use list if we just did the free list. */
297 if (in_free_list) {
298 in_free_list = false;
299 idx = le16_to_cpu(ra->client_in_use_list);
300 goto check_list;
301 }
302 ntfs_debug("Done.");
303 return true;
304err_out:
305 ntfs_error(vi->i_sb, "$LogFile log client array is corrupt.");
306 return false;
307}
308
309/**
310 * ntfs_check_and_load_restart_page - check the restart page for consistency
311 * @vi: $LogFile inode to which the restart page belongs
312 * @rp: restart page to check
313 * @pos: position in @vi at which the restart page resides
314 * @wrp: [OUT] copy of the multi sector transfer deprotected restart page
315 * @lsn: [OUT] set to the current logfile lsn on success
316 *
317 * Check the restart page @rp for consistency and return 0 if it is consistent
318 * and -errno otherwise. The restart page may have been modified by chkdsk in
319 * which case its magic is CHKD instead of RSTR.
320 *
321 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
322 * require the full restart page.
323 *
324 * If @wrp is not NULL, on success, *@wrp will point to a buffer containing a
325 * copy of the complete multi sector transfer deprotected page. On failure,
326 * *@wrp is undefined.
327 *
328 * Simillarly, if @lsn is not NULL, on success *@lsn will be set to the current
329 * logfile lsn according to this restart page. On failure, *@lsn is undefined.
330 *
331 * The following error codes are defined:
332 * -EINVAL - The restart page is inconsistent.
333 * -ENOMEM - Not enough memory to load the restart page.
334 * -EIO - Failed to reading from $LogFile.
335 */
336static int ntfs_check_and_load_restart_page(struct inode *vi,
337 RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp,
338 LSN *lsn)
339{
340 RESTART_AREA *ra;
341 RESTART_PAGE_HEADER *trp;
342 int size, err;
343
344 ntfs_debug("Entering.");
345 /* Check the restart page header for consistency. */
346 if (!ntfs_check_restart_page_header(vi, rp, pos)) {
347 /* Error output already done inside the function. */
348 return -EINVAL;
349 }
350 /* Check the restart area for consistency. */
351 if (!ntfs_check_restart_area(vi, rp)) {
352 /* Error output already done inside the function. */
353 return -EINVAL;
354 }
355 ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
356 /*
357 * Allocate a buffer to store the whole restart page so we can multi
358 * sector transfer deprotect it.
359 */
360 trp = ntfs_malloc_nofs(le32_to_cpu(rp->system_page_size));
361 if (!trp) {
362 ntfs_error(vi->i_sb, "Failed to allocate memory for $LogFile "
363 "restart page buffer.");
364 return -ENOMEM;
365 }
366 /*
367 * Read the whole of the restart page into the buffer. If it fits
368 * completely inside @rp, just copy it from there. Otherwise map all
369 * the required pages and copy the data from them.
370 */
371 size = PAGE_SIZE - (pos & ~PAGE_MASK);
372 if (size >= le32_to_cpu(rp->system_page_size)) {
373 memcpy(trp, rp, le32_to_cpu(rp->system_page_size));
374 } else {
375 pgoff_t idx;
376 struct page *page;
377 int have_read, to_read;
378
379 /* First copy what we already have in @rp. */
380 memcpy(trp, rp, size);
381 /* Copy the remaining data one page at a time. */
382 have_read = size;
383 to_read = le32_to_cpu(rp->system_page_size) - size;
384 idx = (pos + size) >> PAGE_SHIFT;
385 BUG_ON((pos + size) & ~PAGE_MASK);
386 do {
387 page = ntfs_map_page(vi->i_mapping, idx);
388 if (IS_ERR(page)) {
389 ntfs_error(vi->i_sb, "Error mapping $LogFile "
390 "page (index %lu).", idx);
391 err = PTR_ERR(page);
392 if (err != -EIO && err != -ENOMEM)
393 err = -EIO;
394 goto err_out;
395 }
396 size = min_t(int, to_read, PAGE_SIZE);
397 memcpy((u8*)trp + have_read, page_address(page), size);
398 ntfs_unmap_page(page);
399 have_read += size;
400 to_read -= size;
401 idx++;
402 } while (to_read > 0);
403 }
404 /*
405 * Perform the multi sector transfer deprotection on the buffer if the
406 * restart page is protected.
407 */
408 if ((!ntfs_is_chkd_record(trp->magic) || le16_to_cpu(trp->usa_count))
409 && post_read_mst_fixup((NTFS_RECORD*)trp,
410 le32_to_cpu(rp->system_page_size))) {
411 /*
412 * A multi sector tranfer error was detected. We only need to
413 * abort if the restart page contents exceed the multi sector
414 * transfer fixup of the first sector.
415 */
416 if (le16_to_cpu(rp->restart_area_offset) +
417 le16_to_cpu(ra->restart_area_length) >
418 NTFS_BLOCK_SIZE - sizeof(u16)) {
419 ntfs_error(vi->i_sb, "Multi sector transfer error "
420 "detected in $LogFile restart page.");
421 err = -EINVAL;
422 goto err_out;
423 }
424 }
425 /*
426 * If the restart page is modified by chkdsk or there are no active
427 * logfile clients, the logfile is consistent. Otherwise, need to
428 * check the log client records for consistency, too.
429 */
430 err = 0;
431 if (ntfs_is_rstr_record(rp->magic) &&
432 ra->client_in_use_list != LOGFILE_NO_CLIENT) {
433 if (!ntfs_check_log_client_array(vi, trp)) {
434 err = -EINVAL;
435 goto err_out;
436 }
437 }
438 if (lsn) {
439 if (ntfs_is_rstr_record(rp->magic))
440 *lsn = sle64_to_cpu(ra->current_lsn);
441 else /* if (ntfs_is_chkd_record(rp->magic)) */
442 *lsn = sle64_to_cpu(rp->chkdsk_lsn);
443 }
444 ntfs_debug("Done.");
445 if (wrp)
446 *wrp = trp;
447 else {
448err_out:
449 ntfs_free(trp);
450 }
451 return err;
452}
453
454/**
455 * ntfs_check_logfile - check the journal for consistency
456 * @log_vi: struct inode of loaded journal $LogFile to check
457 * @rp: [OUT] on success this is a copy of the current restart page
458 *
459 * Check the $LogFile journal for consistency and return 'true' if it is
460 * consistent and 'false' if not. On success, the current restart page is
461 * returned in *@rp. Caller must call ntfs_free(*@rp) when finished with it.
462 *
463 * At present we only check the two restart pages and ignore the log record
464 * pages.
465 *
466 * Note that the MstProtected flag is not set on the $LogFile inode and hence
467 * when reading pages they are not deprotected. This is because we do not know
468 * if the $LogFile was created on a system with a different page size to ours
469 * yet and mst deprotection would fail if our page size is smaller.
470 */
471bool ntfs_check_logfile(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
472{
473 s64 size, pos;
474 LSN rstr1_lsn, rstr2_lsn;
475 ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
476 struct address_space *mapping = log_vi->i_mapping;
477 struct page *page = NULL;
478 u8 *kaddr = NULL;
479 RESTART_PAGE_HEADER *rstr1_ph = NULL;
480 RESTART_PAGE_HEADER *rstr2_ph = NULL;
481 int log_page_size, err;
482 bool logfile_is_empty = true;
483 u8 log_page_bits;
484
485 ntfs_debug("Entering.");
486 /* An empty $LogFile must have been clean before it got emptied. */
487 if (NVolLogFileEmpty(vol))
488 goto is_empty;
489 size = i_size_read(log_vi);
490 /* Make sure the file doesn't exceed the maximum allowed size. */
491 if (size > MaxLogFileSize)
492 size = MaxLogFileSize;
493 /*
494 * Truncate size to a multiple of the page cache size or the default
495 * log page size if the page cache size is between the default log page
496 * log page size if the page cache size is between the default log page
497 * size and twice that.
498 */
499 if (PAGE_SIZE >= DefaultLogPageSize && PAGE_SIZE <=
500 DefaultLogPageSize * 2)
501 log_page_size = DefaultLogPageSize;
502 else
503 log_page_size = PAGE_SIZE;
504 /*
505 * Use ntfs_ffs() instead of ffs() to enable the compiler to
506 * optimize log_page_size and log_page_bits into constants.
507 */
508 log_page_bits = ntfs_ffs(log_page_size) - 1;
509 size &= ~(s64)(log_page_size - 1);
510 /*
511 * Ensure the log file is big enough to store at least the two restart
512 * pages and the minimum number of log record pages.
513 */
514 if (size < log_page_size * 2 || (size - log_page_size * 2) >>
515 log_page_bits < MinLogRecordPages) {
516 ntfs_error(vol->sb, "$LogFile is too small.");
517 return false;
518 }
519 /*
520 * Read through the file looking for a restart page. Since the restart
521 * page header is at the beginning of a page we only need to search at
522 * what could be the beginning of a page (for each page size) rather
523 * than scanning the whole file byte by byte. If all potential places
524 * contain empty and uninitialzed records, the log file can be assumed
525 * to be empty.
526 */
527 for (pos = 0; pos < size; pos <<= 1) {
528 pgoff_t idx = pos >> PAGE_SHIFT;
529 if (!page || page->index != idx) {
530 if (page)
531 ntfs_unmap_page(page);
532 page = ntfs_map_page(mapping, idx);
533 if (IS_ERR(page)) {
534 ntfs_error(vol->sb, "Error mapping $LogFile "
535 "page (index %lu).", idx);
536 goto err_out;
537 }
538 }
539 kaddr = (u8*)page_address(page) + (pos & ~PAGE_MASK);
540 /*
541 * A non-empty block means the logfile is not empty while an
542 * empty block after a non-empty block has been encountered
543 * means we are done.
544 */
545 if (!ntfs_is_empty_recordp((le32*)kaddr))
546 logfile_is_empty = false;
547 else if (!logfile_is_empty)
548 break;
549 /*
550 * A log record page means there cannot be a restart page after
551 * this so no need to continue searching.
552 */
553 if (ntfs_is_rcrd_recordp((le32*)kaddr))
554 break;
555 /* If not a (modified by chkdsk) restart page, continue. */
556 if (!ntfs_is_rstr_recordp((le32*)kaddr) &&
557 !ntfs_is_chkd_recordp((le32*)kaddr)) {
558 if (!pos)
559 pos = NTFS_BLOCK_SIZE >> 1;
560 continue;
561 }
562 /*
563 * Check the (modified by chkdsk) restart page for consistency
564 * and get a copy of the complete multi sector transfer
565 * deprotected restart page.
566 */
567 err = ntfs_check_and_load_restart_page(log_vi,
568 (RESTART_PAGE_HEADER*)kaddr, pos,
569 !rstr1_ph ? &rstr1_ph : &rstr2_ph,
570 !rstr1_ph ? &rstr1_lsn : &rstr2_lsn);
571 if (!err) {
572 /*
573 * If we have now found the first (modified by chkdsk)
574 * restart page, continue looking for the second one.
575 */
576 if (!pos) {
577 pos = NTFS_BLOCK_SIZE >> 1;
578 continue;
579 }
580 /*
581 * We have now found the second (modified by chkdsk)
582 * restart page, so we can stop looking.
583 */
584 break;
585 }
586 /*
587 * Error output already done inside the function. Note, we do
588 * not abort if the restart page was invalid as we might still
589 * find a valid one further in the file.
590 */
591 if (err != -EINVAL) {
592 ntfs_unmap_page(page);
593 goto err_out;
594 }
595 /* Continue looking. */
596 if (!pos)
597 pos = NTFS_BLOCK_SIZE >> 1;
598 }
599 if (page)
600 ntfs_unmap_page(page);
601 if (logfile_is_empty) {
602 NVolSetLogFileEmpty(vol);
603is_empty:
604 ntfs_debug("Done. ($LogFile is empty.)");
605 return true;
606 }
607 if (!rstr1_ph) {
608 BUG_ON(rstr2_ph);
609 ntfs_error(vol->sb, "Did not find any restart pages in "
610 "$LogFile and it was not empty.");
611 return false;
612 }
613 /* If both restart pages were found, use the more recent one. */
614 if (rstr2_ph) {
615 /*
616 * If the second restart area is more recent, switch to it.
617 * Otherwise just throw it away.
618 */
619 if (rstr2_lsn > rstr1_lsn) {
620 ntfs_debug("Using second restart page as it is more "
621 "recent.");
622 ntfs_free(rstr1_ph);
623 rstr1_ph = rstr2_ph;
624 /* rstr1_lsn = rstr2_lsn; */
625 } else {
626 ntfs_debug("Using first restart page as it is more "
627 "recent.");
628 ntfs_free(rstr2_ph);
629 }
630 rstr2_ph = NULL;
631 }
632 /* All consistency checks passed. */
633 if (rp)
634 *rp = rstr1_ph;
635 else
636 ntfs_free(rstr1_ph);
637 ntfs_debug("Done.");
638 return true;
639err_out:
640 if (rstr1_ph)
641 ntfs_free(rstr1_ph);
642 return false;
643}
644
645/**
646 * ntfs_is_logfile_clean - check in the journal if the volume is clean
647 * @log_vi: struct inode of loaded journal $LogFile to check
648 * @rp: copy of the current restart page
649 *
650 * Analyze the $LogFile journal and return 'true' if it indicates the volume was
651 * shutdown cleanly and 'false' if not.
652 *
653 * At present we only look at the two restart pages and ignore the log record
654 * pages. This is a little bit crude in that there will be a very small number
655 * of cases where we think that a volume is dirty when in fact it is clean.
656 * This should only affect volumes that have not been shutdown cleanly but did
657 * not have any pending, non-check-pointed i/o, i.e. they were completely idle
658 * at least for the five seconds preceding the unclean shutdown.
659 *
660 * This function assumes that the $LogFile journal has already been consistency
661 * checked by a call to ntfs_check_logfile() and in particular if the $LogFile
662 * is empty this function requires that NVolLogFileEmpty() is true otherwise an
663 * empty volume will be reported as dirty.
664 */
665bool ntfs_is_logfile_clean(struct inode *log_vi, const RESTART_PAGE_HEADER *rp)
666{
667 ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
668 RESTART_AREA *ra;
669
670 ntfs_debug("Entering.");
671 /* An empty $LogFile must have been clean before it got emptied. */
672 if (NVolLogFileEmpty(vol)) {
673 ntfs_debug("Done. ($LogFile is empty.)");
674 return true;
675 }
676 BUG_ON(!rp);
677 if (!ntfs_is_rstr_record(rp->magic) &&
678 !ntfs_is_chkd_record(rp->magic)) {
679 ntfs_error(vol->sb, "Restart page buffer is invalid. This is "
680 "probably a bug in that the $LogFile should "
681 "have been consistency checked before calling "
682 "this function.");
683 return false;
684 }
685 ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
686 /*
687 * If the $LogFile has active clients, i.e. it is open, and we do not
688 * have the RESTART_VOLUME_IS_CLEAN bit set in the restart area flags,
689 * we assume there was an unclean shutdown.
690 */
691 if (ra->client_in_use_list != LOGFILE_NO_CLIENT &&
692 !(ra->flags & RESTART_VOLUME_IS_CLEAN)) {
693 ntfs_debug("Done. $LogFile indicates a dirty shutdown.");
694 return false;
695 }
696 /* $LogFile indicates a clean shutdown. */
697 ntfs_debug("Done. $LogFile indicates a clean shutdown.");
698 return true;
699}
700
701/**
702 * ntfs_empty_logfile - empty the contents of the $LogFile journal
703 * @log_vi: struct inode of loaded journal $LogFile to empty
704 *
705 * Empty the contents of the $LogFile journal @log_vi and return 'true' on
706 * success and 'false' on error.
707 *
708 * This function assumes that the $LogFile journal has already been consistency
709 * checked by a call to ntfs_check_logfile() and that ntfs_is_logfile_clean()
710 * has been used to ensure that the $LogFile is clean.
711 */
712bool ntfs_empty_logfile(struct inode *log_vi)
713{
714 VCN vcn, end_vcn;
715 ntfs_inode *log_ni = NTFS_I(log_vi);
716 ntfs_volume *vol = log_ni->vol;
717 struct super_block *sb = vol->sb;
718 runlist_element *rl;
719 unsigned long flags;
720 unsigned block_size, block_size_bits;
721 int err;
722 bool should_wait = true;
723
724 ntfs_debug("Entering.");
725 if (NVolLogFileEmpty(vol)) {
726 ntfs_debug("Done.");
727 return true;
728 }
729 /*
730 * We cannot use ntfs_attr_set() because we may be still in the middle
731 * of a mount operation. Thus we do the emptying by hand by first
732 * zapping the page cache pages for the $LogFile/$DATA attribute and
733 * then emptying each of the buffers in each of the clusters specified
734 * by the runlist by hand.
735 */
736 block_size = sb->s_blocksize;
737 block_size_bits = sb->s_blocksize_bits;
738 vcn = 0;
739 read_lock_irqsave(&log_ni->size_lock, flags);
740 end_vcn = (log_ni->initialized_size + vol->cluster_size_mask) >>
741 vol->cluster_size_bits;
742 read_unlock_irqrestore(&log_ni->size_lock, flags);
743 truncate_inode_pages(log_vi->i_mapping, 0);
744 down_write(&log_ni->runlist.lock);
745 rl = log_ni->runlist.rl;
746 if (unlikely(!rl || vcn < rl->vcn || !rl->length)) {
747map_vcn:
748 err = ntfs_map_runlist_nolock(log_ni, vcn, NULL);
749 if (err) {
750 ntfs_error(sb, "Failed to map runlist fragment (error "
751 "%d).", -err);
752 goto err;
753 }
754 rl = log_ni->runlist.rl;
755 BUG_ON(!rl || vcn < rl->vcn || !rl->length);
756 }
757 /* Seek to the runlist element containing @vcn. */
758 while (rl->length && vcn >= rl[1].vcn)
759 rl++;
760 do {
761 LCN lcn;
762 sector_t block, end_block;
763 s64 len;
764
765 /*
766 * If this run is not mapped map it now and start again as the
767 * runlist will have been updated.
768 */
769 lcn = rl->lcn;
770 if (unlikely(lcn == LCN_RL_NOT_MAPPED)) {
771 vcn = rl->vcn;
772 goto map_vcn;
773 }
774 /* If this run is not valid abort with an error. */
775 if (unlikely(!rl->length || lcn < LCN_HOLE))
776 goto rl_err;
777 /* Skip holes. */
778 if (lcn == LCN_HOLE)
779 continue;
780 block = lcn << vol->cluster_size_bits >> block_size_bits;
781 len = rl->length;
782 if (rl[1].vcn > end_vcn)
783 len = end_vcn - rl->vcn;
784 end_block = (lcn + len) << vol->cluster_size_bits >>
785 block_size_bits;
786 /* Iterate over the blocks in the run and empty them. */
787 do {
788 struct buffer_head *bh;
789
790 /* Obtain the buffer, possibly not uptodate. */
791 bh = sb_getblk(sb, block);
792 BUG_ON(!bh);
793 /* Setup buffer i/o submission. */
794 lock_buffer(bh);
795 bh->b_end_io = end_buffer_write_sync;
796 get_bh(bh);
797 /* Set the entire contents of the buffer to 0xff. */
798 memset(bh->b_data, -1, block_size);
799 if (!buffer_uptodate(bh))
800 set_buffer_uptodate(bh);
801 if (buffer_dirty(bh))
802 clear_buffer_dirty(bh);
803 /*
804 * Submit the buffer and wait for i/o to complete but
805 * only for the first buffer so we do not miss really
806 * serious i/o errors. Once the first buffer has
807 * completed ignore errors afterwards as we can assume
808 * that if one buffer worked all of them will work.
809 */
810 submit_bh(REQ_OP_WRITE, bh);
811 if (should_wait) {
812 should_wait = false;
813 wait_on_buffer(bh);
814 if (unlikely(!buffer_uptodate(bh)))
815 goto io_err;
816 }
817 brelse(bh);
818 } while (++block < end_block);
819 } while ((++rl)->vcn < end_vcn);
820 up_write(&log_ni->runlist.lock);
821 /*
822 * Zap the pages again just in case any got instantiated whilst we were
823 * emptying the blocks by hand. FIXME: We may not have completed
824 * writing to all the buffer heads yet so this may happen too early.
825 * We really should use a kernel thread to do the emptying
826 * asynchronously and then we can also set the volume dirty and output
827 * an error message if emptying should fail.
828 */
829 truncate_inode_pages(log_vi->i_mapping, 0);
830 /* Set the flag so we do not have to do it again on remount. */
831 NVolSetLogFileEmpty(vol);
832 ntfs_debug("Done.");
833 return true;
834io_err:
835 ntfs_error(sb, "Failed to write buffer. Unmount and run chkdsk.");
836 goto dirty_err;
837rl_err:
838 ntfs_error(sb, "Runlist is corrupt. Unmount and run chkdsk.");
839dirty_err:
840 NVolSetErrors(vol);
841 err = -EIO;
842err:
843 up_write(&log_ni->runlist.lock);
844 ntfs_error(sb, "Failed to fill $LogFile with 0xff bytes (error %d).",
845 -err);
846 return false;
847}
848
849#endif /* NTFS_RW */
850

source code of linux/fs/ntfs/logfile.c