Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[wrt350n-kernel.git] / fs / ntfs / logfile.c
blobd7932e95b1fdfe09ad3e46c78799aa1304d87dc5
1 /*
2 * logfile.c - NTFS kernel journal handling. Part of the Linux-NTFS project.
4 * Copyright (c) 2002-2007 Anton Altaparmakov
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.
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.
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
22 #ifdef NTFS_RW
24 #include <linux/types.h>
25 #include <linux/fs.h>
26 #include <linux/highmem.h>
27 #include <linux/buffer_head.h>
28 #include <linux/bitops.h>
30 #include "attrib.h"
31 #include "aops.h"
32 #include "debug.h"
33 #include "logfile.h"
34 #include "malloc.h"
35 #include "volume.h"
36 #include "ntfs.h"
38 /**
39 * ntfs_check_restart_page_header - check the page header for consistency
40 * @vi: $LogFile inode to which the restart page header belongs
41 * @rp: restart page header to check
42 * @pos: position in @vi at which the restart page header resides
44 * Check the restart page header @rp for consistency and return 'true' if it is
45 * consistent and 'false' otherwise.
47 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
48 * require the full restart page.
50 static bool ntfs_check_restart_page_header(struct inode *vi,
51 RESTART_PAGE_HEADER *rp, s64 pos)
53 u32 logfile_system_page_size, logfile_log_page_size;
54 u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
55 bool have_usa = true;
57 ntfs_debug("Entering.");
59 * If the system or log page sizes are smaller than the ntfs block size
60 * or either is not a power of 2 we cannot handle this log file.
62 logfile_system_page_size = le32_to_cpu(rp->system_page_size);
63 logfile_log_page_size = le32_to_cpu(rp->log_page_size);
64 if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
65 logfile_log_page_size < NTFS_BLOCK_SIZE ||
66 logfile_system_page_size &
67 (logfile_system_page_size - 1) ||
68 logfile_log_page_size & (logfile_log_page_size - 1)) {
69 ntfs_error(vi->i_sb, "$LogFile uses unsupported page size.");
70 return false;
73 * We must be either at !pos (1st restart page) or at pos = system page
74 * size (2nd restart page).
76 if (pos && pos != logfile_system_page_size) {
77 ntfs_error(vi->i_sb, "Found restart area in incorrect "
78 "position in $LogFile.");
79 return false;
81 /* We only know how to handle version 1.1. */
82 if (sle16_to_cpu(rp->major_ver) != 1 ||
83 sle16_to_cpu(rp->minor_ver) != 1) {
84 ntfs_error(vi->i_sb, "$LogFile version %i.%i is not "
85 "supported. (This driver supports version "
86 "1.1 only.)", (int)sle16_to_cpu(rp->major_ver),
87 (int)sle16_to_cpu(rp->minor_ver));
88 return false;
91 * If chkdsk has been run the restart page may not be protected by an
92 * update sequence array.
94 if (ntfs_is_chkd_record(rp->magic) && !le16_to_cpu(rp->usa_count)) {
95 have_usa = false;
96 goto skip_usa_checks;
98 /* Verify the size of the update sequence array. */
99 usa_count = 1 + (logfile_system_page_size >> NTFS_BLOCK_SIZE_BITS);
100 if (usa_count != le16_to_cpu(rp->usa_count)) {
101 ntfs_error(vi->i_sb, "$LogFile restart page specifies "
102 "inconsistent update sequence array count.");
103 return false;
105 /* Verify the position of the update sequence array. */
106 usa_ofs = le16_to_cpu(rp->usa_ofs);
107 usa_end = usa_ofs + usa_count * sizeof(u16);
108 if (usa_ofs < sizeof(RESTART_PAGE_HEADER) ||
109 usa_end > NTFS_BLOCK_SIZE - sizeof(u16)) {
110 ntfs_error(vi->i_sb, "$LogFile restart page specifies "
111 "inconsistent update sequence array offset.");
112 return false;
114 skip_usa_checks:
116 * Verify the position of the restart area. It must be:
117 * - aligned to 8-byte boundary,
118 * - after the update sequence array, and
119 * - within the system page size.
121 ra_ofs = le16_to_cpu(rp->restart_area_offset);
122 if (ra_ofs & 7 || (have_usa ? ra_ofs < usa_end :
123 ra_ofs < sizeof(RESTART_PAGE_HEADER)) ||
124 ra_ofs > logfile_system_page_size) {
125 ntfs_error(vi->i_sb, "$LogFile restart page specifies "
126 "inconsistent restart area offset.");
127 return false;
130 * Only restart pages modified by chkdsk are allowed to have chkdsk_lsn
131 * set.
133 if (!ntfs_is_chkd_record(rp->magic) && sle64_to_cpu(rp->chkdsk_lsn)) {
134 ntfs_error(vi->i_sb, "$LogFile restart page is not modified "
135 "by chkdsk but a chkdsk LSN is specified.");
136 return false;
138 ntfs_debug("Done.");
139 return true;
143 * ntfs_check_restart_area - check the restart area for consistency
144 * @vi: $LogFile inode to which the restart page belongs
145 * @rp: restart page whose restart area to check
147 * Check the restart area of the restart page @rp for consistency and return
148 * 'true' if it is consistent and 'false' otherwise.
150 * This function assumes that the restart page header has already been
151 * consistency checked.
153 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
154 * require the full restart page.
156 static bool ntfs_check_restart_area(struct inode *vi, RESTART_PAGE_HEADER *rp)
158 u64 file_size;
159 RESTART_AREA *ra;
160 u16 ra_ofs, ra_len, ca_ofs;
161 u8 fs_bits;
163 ntfs_debug("Entering.");
164 ra_ofs = le16_to_cpu(rp->restart_area_offset);
165 ra = (RESTART_AREA*)((u8*)rp + ra_ofs);
167 * Everything before ra->file_size must be before the first word
168 * protected by an update sequence number. This ensures that it is
169 * safe to access ra->client_array_offset.
171 if (ra_ofs + offsetof(RESTART_AREA, file_size) >
172 NTFS_BLOCK_SIZE - sizeof(u16)) {
173 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
174 "inconsistent file offset.");
175 return false;
178 * Now that we can access ra->client_array_offset, make sure everything
179 * up to the log client array is before the first word protected by an
180 * update sequence number. This ensures we can access all of the
181 * restart area elements safely. Also, the client array offset must be
182 * aligned to an 8-byte boundary.
184 ca_ofs = le16_to_cpu(ra->client_array_offset);
185 if (((ca_ofs + 7) & ~7) != ca_ofs ||
186 ra_ofs + ca_ofs > NTFS_BLOCK_SIZE - sizeof(u16)) {
187 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
188 "inconsistent client array offset.");
189 return false;
192 * The restart area must end within the system page size both when
193 * calculated manually and as specified by ra->restart_area_length.
194 * Also, the calculated length must not exceed the specified length.
196 ra_len = ca_ofs + le16_to_cpu(ra->log_clients) *
197 sizeof(LOG_CLIENT_RECORD);
198 if (ra_ofs + ra_len > le32_to_cpu(rp->system_page_size) ||
199 ra_ofs + le16_to_cpu(ra->restart_area_length) >
200 le32_to_cpu(rp->system_page_size) ||
201 ra_len > le16_to_cpu(ra->restart_area_length)) {
202 ntfs_error(vi->i_sb, "$LogFile restart area is out of bounds "
203 "of the system page size specified by the "
204 "restart page header and/or the specified "
205 "restart area length is inconsistent.");
206 return false;
209 * The ra->client_free_list and ra->client_in_use_list must be either
210 * LOGFILE_NO_CLIENT or less than ra->log_clients or they are
211 * overflowing the client array.
213 if ((ra->client_free_list != LOGFILE_NO_CLIENT &&
214 le16_to_cpu(ra->client_free_list) >=
215 le16_to_cpu(ra->log_clients)) ||
216 (ra->client_in_use_list != LOGFILE_NO_CLIENT &&
217 le16_to_cpu(ra->client_in_use_list) >=
218 le16_to_cpu(ra->log_clients))) {
219 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
220 "overflowing client free and/or in use lists.");
221 return false;
224 * Check ra->seq_number_bits against ra->file_size for consistency.
225 * We cannot just use ffs() because the file size is not a power of 2.
227 file_size = (u64)sle64_to_cpu(ra->file_size);
228 fs_bits = 0;
229 while (file_size) {
230 file_size >>= 1;
231 fs_bits++;
233 if (le32_to_cpu(ra->seq_number_bits) != 67 - fs_bits) {
234 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
235 "inconsistent sequence number bits.");
236 return false;
238 /* The log record header length must be a multiple of 8. */
239 if (((le16_to_cpu(ra->log_record_header_length) + 7) & ~7) !=
240 le16_to_cpu(ra->log_record_header_length)) {
241 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
242 "inconsistent log record header length.");
243 return false;
245 /* Dito for the log page data offset. */
246 if (((le16_to_cpu(ra->log_page_data_offset) + 7) & ~7) !=
247 le16_to_cpu(ra->log_page_data_offset)) {
248 ntfs_error(vi->i_sb, "$LogFile restart area specifies "
249 "inconsistent log page data offset.");
250 return false;
252 ntfs_debug("Done.");
253 return true;
257 * ntfs_check_log_client_array - check the log client array for consistency
258 * @vi: $LogFile inode to which the restart page belongs
259 * @rp: restart page whose log client array to check
261 * Check the log client array of the restart page @rp for consistency and
262 * return 'true' if it is consistent and 'false' otherwise.
264 * This function assumes that the restart page header and the restart area have
265 * already been consistency checked.
267 * Unlike ntfs_check_restart_page_header() and ntfs_check_restart_area(), this
268 * function needs @rp->system_page_size bytes in @rp, i.e. it requires the full
269 * restart page and the page must be multi sector transfer deprotected.
271 static bool ntfs_check_log_client_array(struct inode *vi,
272 RESTART_PAGE_HEADER *rp)
274 RESTART_AREA *ra;
275 LOG_CLIENT_RECORD *ca, *cr;
276 u16 nr_clients, idx;
277 bool in_free_list, idx_is_first;
279 ntfs_debug("Entering.");
280 ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
281 ca = (LOG_CLIENT_RECORD*)((u8*)ra +
282 le16_to_cpu(ra->client_array_offset));
284 * Check the ra->client_free_list first and then check the
285 * ra->client_in_use_list. Check each of the log client records in
286 * each of the lists and check that the array does not overflow the
287 * ra->log_clients value. Also keep track of the number of records
288 * visited as there cannot be more than ra->log_clients records and
289 * that way we detect eventual loops in within a list.
291 nr_clients = le16_to_cpu(ra->log_clients);
292 idx = le16_to_cpu(ra->client_free_list);
293 in_free_list = true;
294 check_list:
295 for (idx_is_first = true; idx != LOGFILE_NO_CLIENT_CPU; nr_clients--,
296 idx = le16_to_cpu(cr->next_client)) {
297 if (!nr_clients || idx >= le16_to_cpu(ra->log_clients))
298 goto err_out;
299 /* Set @cr to the current log client record. */
300 cr = ca + idx;
301 /* The first log client record must not have a prev_client. */
302 if (idx_is_first) {
303 if (cr->prev_client != LOGFILE_NO_CLIENT)
304 goto err_out;
305 idx_is_first = false;
308 /* Switch to and check the in use list if we just did the free list. */
309 if (in_free_list) {
310 in_free_list = false;
311 idx = le16_to_cpu(ra->client_in_use_list);
312 goto check_list;
314 ntfs_debug("Done.");
315 return true;
316 err_out:
317 ntfs_error(vi->i_sb, "$LogFile log client array is corrupt.");
318 return false;
322 * ntfs_check_and_load_restart_page - check the restart page for consistency
323 * @vi: $LogFile inode to which the restart page belongs
324 * @rp: restart page to check
325 * @pos: position in @vi at which the restart page resides
326 * @wrp: [OUT] copy of the multi sector transfer deprotected restart page
327 * @lsn: [OUT] set to the current logfile lsn on success
329 * Check the restart page @rp for consistency and return 0 if it is consistent
330 * and -errno otherwise. The restart page may have been modified by chkdsk in
331 * which case its magic is CHKD instead of RSTR.
333 * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
334 * require the full restart page.
336 * If @wrp is not NULL, on success, *@wrp will point to a buffer containing a
337 * copy of the complete multi sector transfer deprotected page. On failure,
338 * *@wrp is undefined.
340 * Simillarly, if @lsn is not NULL, on succes *@lsn will be set to the current
341 * logfile lsn according to this restart page. On failure, *@lsn is undefined.
343 * The following error codes are defined:
344 * -EINVAL - The restart page is inconsistent.
345 * -ENOMEM - Not enough memory to load the restart page.
346 * -EIO - Failed to reading from $LogFile.
348 static int ntfs_check_and_load_restart_page(struct inode *vi,
349 RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp,
350 LSN *lsn)
352 RESTART_AREA *ra;
353 RESTART_PAGE_HEADER *trp;
354 int size, err;
356 ntfs_debug("Entering.");
357 /* Check the restart page header for consistency. */
358 if (!ntfs_check_restart_page_header(vi, rp, pos)) {
359 /* Error output already done inside the function. */
360 return -EINVAL;
362 /* Check the restart area for consistency. */
363 if (!ntfs_check_restart_area(vi, rp)) {
364 /* Error output already done inside the function. */
365 return -EINVAL;
367 ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
369 * Allocate a buffer to store the whole restart page so we can multi
370 * sector transfer deprotect it.
372 trp = ntfs_malloc_nofs(le32_to_cpu(rp->system_page_size));
373 if (!trp) {
374 ntfs_error(vi->i_sb, "Failed to allocate memory for $LogFile "
375 "restart page buffer.");
376 return -ENOMEM;
379 * Read the whole of the restart page into the buffer. If it fits
380 * completely inside @rp, just copy it from there. Otherwise map all
381 * the required pages and copy the data from them.
383 size = PAGE_CACHE_SIZE - (pos & ~PAGE_CACHE_MASK);
384 if (size >= le32_to_cpu(rp->system_page_size)) {
385 memcpy(trp, rp, le32_to_cpu(rp->system_page_size));
386 } else {
387 pgoff_t idx;
388 struct page *page;
389 int have_read, to_read;
391 /* First copy what we already have in @rp. */
392 memcpy(trp, rp, size);
393 /* Copy the remaining data one page at a time. */
394 have_read = size;
395 to_read = le32_to_cpu(rp->system_page_size) - size;
396 idx = (pos + size) >> PAGE_CACHE_SHIFT;
397 BUG_ON((pos + size) & ~PAGE_CACHE_MASK);
398 do {
399 page = ntfs_map_page(vi->i_mapping, idx);
400 if (IS_ERR(page)) {
401 ntfs_error(vi->i_sb, "Error mapping $LogFile "
402 "page (index %lu).", idx);
403 err = PTR_ERR(page);
404 if (err != -EIO && err != -ENOMEM)
405 err = -EIO;
406 goto err_out;
408 size = min_t(int, to_read, PAGE_CACHE_SIZE);
409 memcpy((u8*)trp + have_read, page_address(page), size);
410 ntfs_unmap_page(page);
411 have_read += size;
412 to_read -= size;
413 idx++;
414 } while (to_read > 0);
417 * Perform the multi sector transfer deprotection on the buffer if the
418 * restart page is protected.
420 if ((!ntfs_is_chkd_record(trp->magic) || le16_to_cpu(trp->usa_count))
421 && post_read_mst_fixup((NTFS_RECORD*)trp,
422 le32_to_cpu(rp->system_page_size))) {
424 * A multi sector tranfer error was detected. We only need to
425 * abort if the restart page contents exceed the multi sector
426 * transfer fixup of the first sector.
428 if (le16_to_cpu(rp->restart_area_offset) +
429 le16_to_cpu(ra->restart_area_length) >
430 NTFS_BLOCK_SIZE - sizeof(u16)) {
431 ntfs_error(vi->i_sb, "Multi sector transfer error "
432 "detected in $LogFile restart page.");
433 err = -EINVAL;
434 goto err_out;
438 * If the restart page is modified by chkdsk or there are no active
439 * logfile clients, the logfile is consistent. Otherwise, need to
440 * check the log client records for consistency, too.
442 err = 0;
443 if (ntfs_is_rstr_record(rp->magic) &&
444 ra->client_in_use_list != LOGFILE_NO_CLIENT) {
445 if (!ntfs_check_log_client_array(vi, trp)) {
446 err = -EINVAL;
447 goto err_out;
450 if (lsn) {
451 if (ntfs_is_rstr_record(rp->magic))
452 *lsn = sle64_to_cpu(ra->current_lsn);
453 else /* if (ntfs_is_chkd_record(rp->magic)) */
454 *lsn = sle64_to_cpu(rp->chkdsk_lsn);
456 ntfs_debug("Done.");
457 if (wrp)
458 *wrp = trp;
459 else {
460 err_out:
461 ntfs_free(trp);
463 return err;
467 * ntfs_check_logfile - check the journal for consistency
468 * @log_vi: struct inode of loaded journal $LogFile to check
469 * @rp: [OUT] on success this is a copy of the current restart page
471 * Check the $LogFile journal for consistency and return 'true' if it is
472 * consistent and 'false' if not. On success, the current restart page is
473 * returned in *@rp. Caller must call ntfs_free(*@rp) when finished with it.
475 * At present we only check the two restart pages and ignore the log record
476 * pages.
478 * Note that the MstProtected flag is not set on the $LogFile inode and hence
479 * when reading pages they are not deprotected. This is because we do not know
480 * if the $LogFile was created on a system with a different page size to ours
481 * yet and mst deprotection would fail if our page size is smaller.
483 bool ntfs_check_logfile(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
485 s64 size, pos;
486 LSN rstr1_lsn, rstr2_lsn;
487 ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
488 struct address_space *mapping = log_vi->i_mapping;
489 struct page *page = NULL;
490 u8 *kaddr = NULL;
491 RESTART_PAGE_HEADER *rstr1_ph = NULL;
492 RESTART_PAGE_HEADER *rstr2_ph = NULL;
493 int log_page_size, log_page_mask, err;
494 bool logfile_is_empty = true;
495 u8 log_page_bits;
497 ntfs_debug("Entering.");
498 /* An empty $LogFile must have been clean before it got emptied. */
499 if (NVolLogFileEmpty(vol))
500 goto is_empty;
501 size = i_size_read(log_vi);
502 /* Make sure the file doesn't exceed the maximum allowed size. */
503 if (size > MaxLogFileSize)
504 size = MaxLogFileSize;
506 * Truncate size to a multiple of the page cache size or the default
507 * log page size if the page cache size is between the default log page
508 * log page size if the page cache size is between the default log page
509 * size and twice that.
511 if (PAGE_CACHE_SIZE >= DefaultLogPageSize && PAGE_CACHE_SIZE <=
512 DefaultLogPageSize * 2)
513 log_page_size = DefaultLogPageSize;
514 else
515 log_page_size = PAGE_CACHE_SIZE;
516 log_page_mask = log_page_size - 1;
518 * Use ntfs_ffs() instead of ffs() to enable the compiler to
519 * optimize log_page_size and log_page_bits into constants.
521 log_page_bits = ntfs_ffs(log_page_size) - 1;
522 size &= ~(s64)(log_page_size - 1);
524 * Ensure the log file is big enough to store at least the two restart
525 * pages and the minimum number of log record pages.
527 if (size < log_page_size * 2 || (size - log_page_size * 2) >>
528 log_page_bits < MinLogRecordPages) {
529 ntfs_error(vol->sb, "$LogFile is too small.");
530 return false;
533 * Read through the file looking for a restart page. Since the restart
534 * page header is at the beginning of a page we only need to search at
535 * what could be the beginning of a page (for each page size) rather
536 * than scanning the whole file byte by byte. If all potential places
537 * contain empty and uninitialzed records, the log file can be assumed
538 * to be empty.
540 for (pos = 0; pos < size; pos <<= 1) {
541 pgoff_t idx = pos >> PAGE_CACHE_SHIFT;
542 if (!page || page->index != idx) {
543 if (page)
544 ntfs_unmap_page(page);
545 page = ntfs_map_page(mapping, idx);
546 if (IS_ERR(page)) {
547 ntfs_error(vol->sb, "Error mapping $LogFile "
548 "page (index %lu).", idx);
549 goto err_out;
552 kaddr = (u8*)page_address(page) + (pos & ~PAGE_CACHE_MASK);
554 * A non-empty block means the logfile is not empty while an
555 * empty block after a non-empty block has been encountered
556 * means we are done.
558 if (!ntfs_is_empty_recordp((le32*)kaddr))
559 logfile_is_empty = false;
560 else if (!logfile_is_empty)
561 break;
563 * A log record page means there cannot be a restart page after
564 * this so no need to continue searching.
566 if (ntfs_is_rcrd_recordp((le32*)kaddr))
567 break;
568 /* If not a (modified by chkdsk) restart page, continue. */
569 if (!ntfs_is_rstr_recordp((le32*)kaddr) &&
570 !ntfs_is_chkd_recordp((le32*)kaddr)) {
571 if (!pos)
572 pos = NTFS_BLOCK_SIZE >> 1;
573 continue;
576 * Check the (modified by chkdsk) restart page for consistency
577 * and get a copy of the complete multi sector transfer
578 * deprotected restart page.
580 err = ntfs_check_and_load_restart_page(log_vi,
581 (RESTART_PAGE_HEADER*)kaddr, pos,
582 !rstr1_ph ? &rstr1_ph : &rstr2_ph,
583 !rstr1_ph ? &rstr1_lsn : &rstr2_lsn);
584 if (!err) {
586 * If we have now found the first (modified by chkdsk)
587 * restart page, continue looking for the second one.
589 if (!pos) {
590 pos = NTFS_BLOCK_SIZE >> 1;
591 continue;
594 * We have now found the second (modified by chkdsk)
595 * restart page, so we can stop looking.
597 break;
600 * Error output already done inside the function. Note, we do
601 * not abort if the restart page was invalid as we might still
602 * find a valid one further in the file.
604 if (err != -EINVAL) {
605 ntfs_unmap_page(page);
606 goto err_out;
608 /* Continue looking. */
609 if (!pos)
610 pos = NTFS_BLOCK_SIZE >> 1;
612 if (page)
613 ntfs_unmap_page(page);
614 if (logfile_is_empty) {
615 NVolSetLogFileEmpty(vol);
616 is_empty:
617 ntfs_debug("Done. ($LogFile is empty.)");
618 return true;
620 if (!rstr1_ph) {
621 BUG_ON(rstr2_ph);
622 ntfs_error(vol->sb, "Did not find any restart pages in "
623 "$LogFile and it was not empty.");
624 return false;
626 /* If both restart pages were found, use the more recent one. */
627 if (rstr2_ph) {
629 * If the second restart area is more recent, switch to it.
630 * Otherwise just throw it away.
632 if (rstr2_lsn > rstr1_lsn) {
633 ntfs_debug("Using second restart page as it is more "
634 "recent.");
635 ntfs_free(rstr1_ph);
636 rstr1_ph = rstr2_ph;
637 /* rstr1_lsn = rstr2_lsn; */
638 } else {
639 ntfs_debug("Using first restart page as it is more "
640 "recent.");
641 ntfs_free(rstr2_ph);
643 rstr2_ph = NULL;
645 /* All consistency checks passed. */
646 if (rp)
647 *rp = rstr1_ph;
648 else
649 ntfs_free(rstr1_ph);
650 ntfs_debug("Done.");
651 return true;
652 err_out:
653 if (rstr1_ph)
654 ntfs_free(rstr1_ph);
655 return false;
659 * ntfs_is_logfile_clean - check in the journal if the volume is clean
660 * @log_vi: struct inode of loaded journal $LogFile to check
661 * @rp: copy of the current restart page
663 * Analyze the $LogFile journal and return 'true' if it indicates the volume was
664 * shutdown cleanly and 'false' if not.
666 * At present we only look at the two restart pages and ignore the log record
667 * pages. This is a little bit crude in that there will be a very small number
668 * of cases where we think that a volume is dirty when in fact it is clean.
669 * This should only affect volumes that have not been shutdown cleanly but did
670 * not have any pending, non-check-pointed i/o, i.e. they were completely idle
671 * at least for the five seconds preceeding the unclean shutdown.
673 * This function assumes that the $LogFile journal has already been consistency
674 * checked by a call to ntfs_check_logfile() and in particular if the $LogFile
675 * is empty this function requires that NVolLogFileEmpty() is true otherwise an
676 * empty volume will be reported as dirty.
678 bool ntfs_is_logfile_clean(struct inode *log_vi, const RESTART_PAGE_HEADER *rp)
680 ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
681 RESTART_AREA *ra;
683 ntfs_debug("Entering.");
684 /* An empty $LogFile must have been clean before it got emptied. */
685 if (NVolLogFileEmpty(vol)) {
686 ntfs_debug("Done. ($LogFile is empty.)");
687 return true;
689 BUG_ON(!rp);
690 if (!ntfs_is_rstr_record(rp->magic) &&
691 !ntfs_is_chkd_record(rp->magic)) {
692 ntfs_error(vol->sb, "Restart page buffer is invalid. This is "
693 "probably a bug in that the $LogFile should "
694 "have been consistency checked before calling "
695 "this function.");
696 return false;
698 ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset));
700 * If the $LogFile has active clients, i.e. it is open, and we do not
701 * have the RESTART_VOLUME_IS_CLEAN bit set in the restart area flags,
702 * we assume there was an unclean shutdown.
704 if (ra->client_in_use_list != LOGFILE_NO_CLIENT &&
705 !(ra->flags & RESTART_VOLUME_IS_CLEAN)) {
706 ntfs_debug("Done. $LogFile indicates a dirty shutdown.");
707 return false;
709 /* $LogFile indicates a clean shutdown. */
710 ntfs_debug("Done. $LogFile indicates a clean shutdown.");
711 return true;
715 * ntfs_empty_logfile - empty the contents of the $LogFile journal
716 * @log_vi: struct inode of loaded journal $LogFile to empty
718 * Empty the contents of the $LogFile journal @log_vi and return 'true' on
719 * success and 'false' on error.
721 * This function assumes that the $LogFile journal has already been consistency
722 * checked by a call to ntfs_check_logfile() and that ntfs_is_logfile_clean()
723 * has been used to ensure that the $LogFile is clean.
725 bool ntfs_empty_logfile(struct inode *log_vi)
727 VCN vcn, end_vcn;
728 ntfs_inode *log_ni = NTFS_I(log_vi);
729 ntfs_volume *vol = log_ni->vol;
730 struct super_block *sb = vol->sb;
731 runlist_element *rl;
732 unsigned long flags;
733 unsigned block_size, block_size_bits;
734 int err;
735 bool should_wait = true;
737 ntfs_debug("Entering.");
738 if (NVolLogFileEmpty(vol)) {
739 ntfs_debug("Done.");
740 return true;
743 * We cannot use ntfs_attr_set() because we may be still in the middle
744 * of a mount operation. Thus we do the emptying by hand by first
745 * zapping the page cache pages for the $LogFile/$DATA attribute and
746 * then emptying each of the buffers in each of the clusters specified
747 * by the runlist by hand.
749 block_size = sb->s_blocksize;
750 block_size_bits = sb->s_blocksize_bits;
751 vcn = 0;
752 read_lock_irqsave(&log_ni->size_lock, flags);
753 end_vcn = (log_ni->initialized_size + vol->cluster_size_mask) >>
754 vol->cluster_size_bits;
755 read_unlock_irqrestore(&log_ni->size_lock, flags);
756 truncate_inode_pages(log_vi->i_mapping, 0);
757 down_write(&log_ni->runlist.lock);
758 rl = log_ni->runlist.rl;
759 if (unlikely(!rl || vcn < rl->vcn || !rl->length)) {
760 map_vcn:
761 err = ntfs_map_runlist_nolock(log_ni, vcn, NULL);
762 if (err) {
763 ntfs_error(sb, "Failed to map runlist fragment (error "
764 "%d).", -err);
765 goto err;
767 rl = log_ni->runlist.rl;
768 BUG_ON(!rl || vcn < rl->vcn || !rl->length);
770 /* Seek to the runlist element containing @vcn. */
771 while (rl->length && vcn >= rl[1].vcn)
772 rl++;
773 do {
774 LCN lcn;
775 sector_t block, end_block;
776 s64 len;
779 * If this run is not mapped map it now and start again as the
780 * runlist will have been updated.
782 lcn = rl->lcn;
783 if (unlikely(lcn == LCN_RL_NOT_MAPPED)) {
784 vcn = rl->vcn;
785 goto map_vcn;
787 /* If this run is not valid abort with an error. */
788 if (unlikely(!rl->length || lcn < LCN_HOLE))
789 goto rl_err;
790 /* Skip holes. */
791 if (lcn == LCN_HOLE)
792 continue;
793 block = lcn << vol->cluster_size_bits >> block_size_bits;
794 len = rl->length;
795 if (rl[1].vcn > end_vcn)
796 len = end_vcn - rl->vcn;
797 end_block = (lcn + len) << vol->cluster_size_bits >>
798 block_size_bits;
799 /* Iterate over the blocks in the run and empty them. */
800 do {
801 struct buffer_head *bh;
803 /* Obtain the buffer, possibly not uptodate. */
804 bh = sb_getblk(sb, block);
805 BUG_ON(!bh);
806 /* Setup buffer i/o submission. */
807 lock_buffer(bh);
808 bh->b_end_io = end_buffer_write_sync;
809 get_bh(bh);
810 /* Set the entire contents of the buffer to 0xff. */
811 memset(bh->b_data, -1, block_size);
812 if (!buffer_uptodate(bh))
813 set_buffer_uptodate(bh);
814 if (buffer_dirty(bh))
815 clear_buffer_dirty(bh);
817 * Submit the buffer and wait for i/o to complete but
818 * only for the first buffer so we do not miss really
819 * serious i/o errors. Once the first buffer has
820 * completed ignore errors afterwards as we can assume
821 * that if one buffer worked all of them will work.
823 submit_bh(WRITE, bh);
824 if (should_wait) {
825 should_wait = false;
826 wait_on_buffer(bh);
827 if (unlikely(!buffer_uptodate(bh)))
828 goto io_err;
830 brelse(bh);
831 } while (++block < end_block);
832 } while ((++rl)->vcn < end_vcn);
833 up_write(&log_ni->runlist.lock);
835 * Zap the pages again just in case any got instantiated whilst we were
836 * emptying the blocks by hand. FIXME: We may not have completed
837 * writing to all the buffer heads yet so this may happen too early.
838 * We really should use a kernel thread to do the emptying
839 * asynchronously and then we can also set the volume dirty and output
840 * an error message if emptying should fail.
842 truncate_inode_pages(log_vi->i_mapping, 0);
843 /* Set the flag so we do not have to do it again on remount. */
844 NVolSetLogFileEmpty(vol);
845 ntfs_debug("Done.");
846 return true;
847 io_err:
848 ntfs_error(sb, "Failed to write buffer. Unmount and run chkdsk.");
849 goto dirty_err;
850 rl_err:
851 ntfs_error(sb, "Runlist is corrupt. Unmount and run chkdsk.");
852 dirty_err:
853 NVolSetErrors(vol);
854 err = -EIO;
855 err:
856 up_write(&log_ni->runlist.lock);
857 ntfs_error(sb, "Failed to fill $LogFile with 0xff bytes (error %d).",
858 -err);
859 return false;
862 #endif /* NTFS_RW */