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1da177e4 LT |
1 | /* |
2 | * logfile.c - NTFS kernel journal handling. Part of the Linux-NTFS project. | |
3 | * | |
3bd1f4a1 | 4 | * Copyright (c) 2002-2005 Anton Altaparmakov |
1da177e4 LT |
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/types.h> | |
25 | #include <linux/fs.h> | |
26 | #include <linux/highmem.h> | |
27 | #include <linux/buffer_head.h> | |
28 | #include <linux/bitops.h> | |
29 | ||
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" | |
37 | ||
38 | /** | |
39 | * ntfs_check_restart_page_header - check the page header for consistency | |
40 | * @vi: $LogFile inode to which the restart page header belongs | |
41 | * @rp: restart page header to check | |
42 | * @pos: position in @vi at which the restart page header resides | |
43 | * | |
44 | * Check the restart page header @rp for consistency and return TRUE if it is | |
45 | * consistent and FALSE otherwise. | |
46 | * | |
47 | * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not | |
48 | * require the full restart page. | |
49 | */ | |
50 | static BOOL ntfs_check_restart_page_header(struct inode *vi, | |
51 | RESTART_PAGE_HEADER *rp, s64 pos) | |
52 | { | |
53 | u32 logfile_system_page_size, logfile_log_page_size; | |
54 | u16 usa_count, usa_ofs, usa_end, ra_ofs; | |
55 | ||
56 | ntfs_debug("Entering."); | |
57 | /* | |
58 | * If the system or log page sizes are smaller than the ntfs block size | |
59 | * or either is not a power of 2 we cannot handle this log file. | |
60 | */ | |
61 | logfile_system_page_size = le32_to_cpu(rp->system_page_size); | |
62 | logfile_log_page_size = le32_to_cpu(rp->log_page_size); | |
63 | if (logfile_system_page_size < NTFS_BLOCK_SIZE || | |
64 | logfile_log_page_size < NTFS_BLOCK_SIZE || | |
65 | logfile_system_page_size & | |
66 | (logfile_system_page_size - 1) || | |
67 | logfile_log_page_size & (logfile_log_page_size - 1)) { | |
68 | ntfs_error(vi->i_sb, "$LogFile uses unsupported page size."); | |
69 | return FALSE; | |
70 | } | |
71 | /* | |
72 | * We must be either at !pos (1st restart page) or at pos = system page | |
73 | * size (2nd restart page). | |
74 | */ | |
75 | if (pos && pos != logfile_system_page_size) { | |
76 | ntfs_error(vi->i_sb, "Found restart area in incorrect " | |
77 | "position in $LogFile."); | |
78 | return FALSE; | |
79 | } | |
80 | /* We only know how to handle version 1.1. */ | |
81 | if (sle16_to_cpu(rp->major_ver) != 1 || | |
82 | sle16_to_cpu(rp->minor_ver) != 1) { | |
83 | ntfs_error(vi->i_sb, "$LogFile version %i.%i is not " | |
84 | "supported. (This driver supports version " | |
85 | "1.1 only.)", (int)sle16_to_cpu(rp->major_ver), | |
86 | (int)sle16_to_cpu(rp->minor_ver)); | |
87 | return FALSE; | |
88 | } | |
89 | /* Verify the size of the update sequence array. */ | |
90 | usa_count = 1 + (logfile_system_page_size >> NTFS_BLOCK_SIZE_BITS); | |
91 | if (usa_count != le16_to_cpu(rp->usa_count)) { | |
92 | ntfs_error(vi->i_sb, "$LogFile restart page specifies " | |
93 | "inconsistent update sequence array count."); | |
94 | return FALSE; | |
95 | } | |
96 | /* Verify the position of the update sequence array. */ | |
97 | usa_ofs = le16_to_cpu(rp->usa_ofs); | |
98 | usa_end = usa_ofs + usa_count * sizeof(u16); | |
99 | if (usa_ofs < sizeof(RESTART_PAGE_HEADER) || | |
100 | usa_end > NTFS_BLOCK_SIZE - sizeof(u16)) { | |
101 | ntfs_error(vi->i_sb, "$LogFile restart page specifies " | |
102 | "inconsistent update sequence array offset."); | |
103 | return FALSE; | |
104 | } | |
105 | /* | |
106 | * Verify the position of the restart area. It must be: | |
107 | * - aligned to 8-byte boundary, | |
108 | * - after the update sequence array, and | |
109 | * - within the system page size. | |
110 | */ | |
111 | ra_ofs = le16_to_cpu(rp->restart_area_offset); | |
112 | if (ra_ofs & 7 || ra_ofs < usa_end || | |
113 | ra_ofs > logfile_system_page_size) { | |
114 | ntfs_error(vi->i_sb, "$LogFile restart page specifies " | |
115 | "inconsistent restart area offset."); | |
116 | return FALSE; | |
117 | } | |
118 | /* | |
119 | * Only restart pages modified by chkdsk are allowed to have chkdsk_lsn | |
120 | * set. | |
121 | */ | |
122 | if (!ntfs_is_chkd_record(rp->magic) && sle64_to_cpu(rp->chkdsk_lsn)) { | |
123 | ntfs_error(vi->i_sb, "$LogFile restart page is not modified " | |
124 | "chkdsk but a chkdsk LSN is specified."); | |
125 | return FALSE; | |
126 | } | |
127 | ntfs_debug("Done."); | |
128 | return TRUE; | |
129 | } | |
130 | ||
131 | /** | |
132 | * ntfs_check_restart_area - check the restart area for consistency | |
133 | * @vi: $LogFile inode to which the restart page belongs | |
134 | * @rp: restart page whose restart area to check | |
135 | * | |
136 | * Check the restart area of the restart page @rp for consistency and return | |
137 | * TRUE if it is consistent and FALSE otherwise. | |
138 | * | |
139 | * This function assumes that the restart page header has already been | |
140 | * consistency checked. | |
141 | * | |
142 | * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not | |
143 | * require the full restart page. | |
144 | */ | |
145 | static BOOL ntfs_check_restart_area(struct inode *vi, RESTART_PAGE_HEADER *rp) | |
146 | { | |
147 | u64 file_size; | |
148 | RESTART_AREA *ra; | |
149 | u16 ra_ofs, ra_len, ca_ofs; | |
150 | u8 fs_bits; | |
151 | ||
152 | ntfs_debug("Entering."); | |
153 | ra_ofs = le16_to_cpu(rp->restart_area_offset); | |
154 | ra = (RESTART_AREA*)((u8*)rp + ra_ofs); | |
155 | /* | |
156 | * Everything before ra->file_size must be before the first word | |
157 | * protected by an update sequence number. This ensures that it is | |
158 | * safe to access ra->client_array_offset. | |
159 | */ | |
160 | if (ra_ofs + offsetof(RESTART_AREA, file_size) > | |
161 | NTFS_BLOCK_SIZE - sizeof(u16)) { | |
162 | ntfs_error(vi->i_sb, "$LogFile restart area specifies " | |
163 | "inconsistent file offset."); | |
164 | return FALSE; | |
165 | } | |
166 | /* | |
167 | * Now that we can access ra->client_array_offset, make sure everything | |
168 | * up to the log client array is before the first word protected by an | |
169 | * update sequence number. This ensures we can access all of the | |
170 | * restart area elements safely. Also, the client array offset must be | |
171 | * aligned to an 8-byte boundary. | |
172 | */ | |
173 | ca_ofs = le16_to_cpu(ra->client_array_offset); | |
174 | if (((ca_ofs + 7) & ~7) != ca_ofs || | |
175 | ra_ofs + ca_ofs > NTFS_BLOCK_SIZE - sizeof(u16)) { | |
176 | ntfs_error(vi->i_sb, "$LogFile restart area specifies " | |
177 | "inconsistent client array offset."); | |
178 | return FALSE; | |
179 | } | |
180 | /* | |
181 | * The restart area must end within the system page size both when | |
182 | * calculated manually and as specified by ra->restart_area_length. | |
183 | * Also, the calculated length must not exceed the specified length. | |
184 | */ | |
185 | ra_len = ca_ofs + le16_to_cpu(ra->log_clients) * | |
186 | sizeof(LOG_CLIENT_RECORD); | |
187 | if (ra_ofs + ra_len > le32_to_cpu(rp->system_page_size) || | |
188 | ra_ofs + le16_to_cpu(ra->restart_area_length) > | |
189 | le32_to_cpu(rp->system_page_size) || | |
190 | ra_len > le16_to_cpu(ra->restart_area_length)) { | |
191 | ntfs_error(vi->i_sb, "$LogFile restart area is out of bounds " | |
192 | "of the system page size specified by the " | |
193 | "restart page header and/or the specified " | |
194 | "restart area length is inconsistent."); | |
195 | return FALSE; | |
196 | } | |
197 | /* | |
198 | * The ra->client_free_list and ra->client_in_use_list must be either | |
199 | * LOGFILE_NO_CLIENT or less than ra->log_clients or they are | |
200 | * overflowing the client array. | |
201 | */ | |
202 | if ((ra->client_free_list != LOGFILE_NO_CLIENT && | |
203 | le16_to_cpu(ra->client_free_list) >= | |
204 | le16_to_cpu(ra->log_clients)) || | |
205 | (ra->client_in_use_list != LOGFILE_NO_CLIENT && | |
206 | le16_to_cpu(ra->client_in_use_list) >= | |
207 | le16_to_cpu(ra->log_clients))) { | |
208 | ntfs_error(vi->i_sb, "$LogFile restart area specifies " | |
209 | "overflowing client free and/or in use lists."); | |
210 | return FALSE; | |
211 | } | |
212 | /* | |
213 | * Check ra->seq_number_bits against ra->file_size for consistency. | |
214 | * We cannot just use ffs() because the file size is not a power of 2. | |
215 | */ | |
216 | file_size = (u64)sle64_to_cpu(ra->file_size); | |
217 | fs_bits = 0; | |
218 | while (file_size) { | |
219 | file_size >>= 1; | |
220 | fs_bits++; | |
221 | } | |
222 | if (le32_to_cpu(ra->seq_number_bits) != 67 - fs_bits) { | |
223 | ntfs_error(vi->i_sb, "$LogFile restart area specifies " | |
224 | "inconsistent sequence number bits."); | |
225 | return FALSE; | |
226 | } | |
227 | /* The log record header length must be a multiple of 8. */ | |
228 | if (((le16_to_cpu(ra->log_record_header_length) + 7) & ~7) != | |
229 | le16_to_cpu(ra->log_record_header_length)) { | |
230 | ntfs_error(vi->i_sb, "$LogFile restart area specifies " | |
231 | "inconsistent log record header length."); | |
232 | return FALSE; | |
233 | } | |
234 | /* Dito for the log page data offset. */ | |
235 | if (((le16_to_cpu(ra->log_page_data_offset) + 7) & ~7) != | |
236 | le16_to_cpu(ra->log_page_data_offset)) { | |
237 | ntfs_error(vi->i_sb, "$LogFile restart area specifies " | |
238 | "inconsistent log page data offset."); | |
239 | return FALSE; | |
240 | } | |
241 | ntfs_debug("Done."); | |
242 | return TRUE; | |
243 | } | |
244 | ||
245 | /** | |
246 | * ntfs_check_log_client_array - check the log client array for consistency | |
247 | * @vi: $LogFile inode to which the restart page belongs | |
248 | * @rp: restart page whose log client array to check | |
249 | * | |
250 | * Check the log client array of the restart page @rp for consistency and | |
251 | * return TRUE if it is consistent and FALSE otherwise. | |
252 | * | |
253 | * This function assumes that the restart page header and the restart area have | |
254 | * already been consistency checked. | |
255 | * | |
256 | * Unlike ntfs_check_restart_page_header() and ntfs_check_restart_area(), this | |
257 | * function needs @rp->system_page_size bytes in @rp, i.e. it requires the full | |
258 | * restart page and the page must be multi sector transfer deprotected. | |
259 | */ | |
260 | static BOOL ntfs_check_log_client_array(struct inode *vi, | |
261 | RESTART_PAGE_HEADER *rp) | |
262 | { | |
263 | RESTART_AREA *ra; | |
264 | LOG_CLIENT_RECORD *ca, *cr; | |
265 | u16 nr_clients, idx; | |
266 | BOOL in_free_list, idx_is_first; | |
267 | ||
268 | ntfs_debug("Entering."); | |
269 | ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset)); | |
270 | ca = (LOG_CLIENT_RECORD*)((u8*)ra + | |
271 | le16_to_cpu(ra->client_array_offset)); | |
272 | /* | |
273 | * Check the ra->client_free_list first and then check the | |
274 | * ra->client_in_use_list. Check each of the log client records in | |
275 | * each of the lists and check that the array does not overflow the | |
276 | * ra->log_clients value. Also keep track of the number of records | |
277 | * visited as there cannot be more than ra->log_clients records and | |
278 | * that way we detect eventual loops in within a list. | |
279 | */ | |
280 | nr_clients = le16_to_cpu(ra->log_clients); | |
281 | idx = le16_to_cpu(ra->client_free_list); | |
282 | in_free_list = TRUE; | |
283 | check_list: | |
284 | for (idx_is_first = TRUE; idx != LOGFILE_NO_CLIENT_CPU; nr_clients--, | |
285 | idx = le16_to_cpu(cr->next_client)) { | |
286 | if (!nr_clients || idx >= le16_to_cpu(ra->log_clients)) | |
287 | goto err_out; | |
288 | /* Set @cr to the current log client record. */ | |
289 | cr = ca + idx; | |
290 | /* The first log client record must not have a prev_client. */ | |
291 | if (idx_is_first) { | |
292 | if (cr->prev_client != LOGFILE_NO_CLIENT) | |
293 | goto err_out; | |
294 | idx_is_first = FALSE; | |
295 | } | |
296 | } | |
297 | /* Switch to and check the in use list if we just did the free list. */ | |
298 | if (in_free_list) { | |
299 | in_free_list = FALSE; | |
300 | idx = le16_to_cpu(ra->client_in_use_list); | |
301 | goto check_list; | |
302 | } | |
303 | ntfs_debug("Done."); | |
304 | return TRUE; | |
305 | err_out: | |
306 | ntfs_error(vi->i_sb, "$LogFile log client array is corrupt."); | |
307 | return FALSE; | |
308 | } | |
309 | ||
310 | /** | |
311 | * ntfs_check_and_load_restart_page - check the restart page for consistency | |
312 | * @vi: $LogFile inode to which the restart page belongs | |
313 | * @rp: restart page to check | |
314 | * @pos: position in @vi at which the restart page resides | |
315 | * @wrp: copy of the multi sector transfer deprotected restart page | |
316 | * | |
317 | * Check the restart page @rp for consistency and return TRUE if it is | |
318 | * consistent and FALSE otherwise. | |
319 | * | |
320 | * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not | |
321 | * require the full restart page. | |
322 | * | |
323 | * If @wrp is not NULL, on success, *@wrp will point to a buffer containing a | |
324 | * copy of the complete multi sector transfer deprotected page. On failure, | |
325 | * *@wrp is undefined. | |
326 | */ | |
327 | static BOOL ntfs_check_and_load_restart_page(struct inode *vi, | |
328 | RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp) | |
329 | { | |
330 | RESTART_AREA *ra; | |
331 | RESTART_PAGE_HEADER *trp; | |
332 | int size; | |
333 | BOOL ret; | |
334 | ||
335 | ntfs_debug("Entering."); | |
336 | /* Check the restart page header for consistency. */ | |
337 | if (!ntfs_check_restart_page_header(vi, rp, pos)) { | |
338 | /* Error output already done inside the function. */ | |
339 | return FALSE; | |
340 | } | |
341 | /* Check the restart area for consistency. */ | |
342 | if (!ntfs_check_restart_area(vi, rp)) { | |
343 | /* Error output already done inside the function. */ | |
344 | return FALSE; | |
345 | } | |
346 | ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset)); | |
347 | /* | |
348 | * Allocate a buffer to store the whole restart page so we can multi | |
349 | * sector transfer deprotect it. | |
350 | */ | |
351 | trp = ntfs_malloc_nofs(le32_to_cpu(rp->system_page_size)); | |
352 | if (!trp) { | |
353 | ntfs_error(vi->i_sb, "Failed to allocate memory for $LogFile " | |
354 | "restart page buffer."); | |
355 | return FALSE; | |
356 | } | |
357 | /* | |
358 | * Read the whole of the restart page into the buffer. If it fits | |
359 | * completely inside @rp, just copy it from there. Otherwise map all | |
360 | * the required pages and copy the data from them. | |
361 | */ | |
362 | size = PAGE_CACHE_SIZE - (pos & ~PAGE_CACHE_MASK); | |
363 | if (size >= le32_to_cpu(rp->system_page_size)) { | |
364 | memcpy(trp, rp, le32_to_cpu(rp->system_page_size)); | |
365 | } else { | |
366 | pgoff_t idx; | |
367 | struct page *page; | |
368 | int have_read, to_read; | |
369 | ||
370 | /* First copy what we already have in @rp. */ | |
371 | memcpy(trp, rp, size); | |
372 | /* Copy the remaining data one page at a time. */ | |
373 | have_read = size; | |
374 | to_read = le32_to_cpu(rp->system_page_size) - size; | |
375 | idx = (pos + size) >> PAGE_CACHE_SHIFT; | |
376 | BUG_ON((pos + size) & ~PAGE_CACHE_MASK); | |
377 | do { | |
378 | page = ntfs_map_page(vi->i_mapping, idx); | |
379 | if (IS_ERR(page)) { | |
380 | ntfs_error(vi->i_sb, "Error mapping $LogFile " | |
381 | "page (index %lu).", idx); | |
382 | goto err_out; | |
383 | } | |
384 | size = min_t(int, to_read, PAGE_CACHE_SIZE); | |
385 | memcpy((u8*)trp + have_read, page_address(page), size); | |
386 | ntfs_unmap_page(page); | |
387 | have_read += size; | |
388 | to_read -= size; | |
389 | idx++; | |
390 | } while (to_read > 0); | |
391 | } | |
392 | /* Perform the multi sector transfer deprotection on the buffer. */ | |
393 | if (post_read_mst_fixup((NTFS_RECORD*)trp, | |
394 | le32_to_cpu(rp->system_page_size))) { | |
395 | ntfs_error(vi->i_sb, "Multi sector transfer error detected in " | |
396 | "$LogFile restart page."); | |
397 | goto err_out; | |
398 | } | |
399 | /* Check the log client records for consistency. */ | |
400 | ret = ntfs_check_log_client_array(vi, trp); | |
401 | if (ret && wrp) | |
402 | *wrp = trp; | |
403 | else | |
404 | ntfs_free(trp); | |
405 | ntfs_debug("Done."); | |
406 | return ret; | |
407 | err_out: | |
408 | ntfs_free(trp); | |
409 | return FALSE; | |
410 | } | |
411 | ||
412 | /** | |
3bd1f4a1 | 413 | * ntfs_check_logfile - check the journal for consistency |
1da177e4 LT |
414 | * @log_vi: struct inode of loaded journal $LogFile to check |
415 | * | |
416 | * Check the $LogFile journal for consistency and return TRUE if it is | |
417 | * consistent and FALSE if not. | |
418 | * | |
419 | * At present we only check the two restart pages and ignore the log record | |
420 | * pages. | |
421 | * | |
422 | * Note that the MstProtected flag is not set on the $LogFile inode and hence | |
423 | * when reading pages they are not deprotected. This is because we do not know | |
424 | * if the $LogFile was created on a system with a different page size to ours | |
425 | * yet and mst deprotection would fail if our page size is smaller. | |
426 | */ | |
427 | BOOL ntfs_check_logfile(struct inode *log_vi) | |
428 | { | |
429 | s64 size, pos, rstr1_pos, rstr2_pos; | |
430 | ntfs_volume *vol = NTFS_SB(log_vi->i_sb); | |
431 | struct address_space *mapping = log_vi->i_mapping; | |
432 | struct page *page = NULL; | |
433 | u8 *kaddr = NULL; | |
434 | RESTART_PAGE_HEADER *rstr1_ph = NULL; | |
435 | RESTART_PAGE_HEADER *rstr2_ph = NULL; | |
436 | int log_page_size, log_page_mask, ofs; | |
437 | BOOL logfile_is_empty = TRUE; | |
438 | BOOL rstr1_found = FALSE; | |
439 | BOOL rstr2_found = FALSE; | |
440 | u8 log_page_bits; | |
441 | ||
442 | ntfs_debug("Entering."); | |
443 | /* An empty $LogFile must have been clean before it got emptied. */ | |
444 | if (NVolLogFileEmpty(vol)) | |
445 | goto is_empty; | |
66129f88 | 446 | size = i_size_read(log_vi); |
1da177e4 LT |
447 | /* Make sure the file doesn't exceed the maximum allowed size. */ |
448 | if (size > MaxLogFileSize) | |
449 | size = MaxLogFileSize; | |
450 | /* | |
451 | * Truncate size to a multiple of the page cache size or the default | |
452 | * log page size if the page cache size is between the default log page | |
453 | * log page size if the page cache size is between the default log page | |
454 | * size and twice that. | |
455 | */ | |
456 | if (PAGE_CACHE_SIZE >= DefaultLogPageSize && PAGE_CACHE_SIZE <= | |
457 | DefaultLogPageSize * 2) | |
458 | log_page_size = DefaultLogPageSize; | |
459 | else | |
460 | log_page_size = PAGE_CACHE_SIZE; | |
461 | log_page_mask = log_page_size - 1; | |
462 | /* | |
463 | * Use generic_ffs() instead of ffs() to enable the compiler to | |
464 | * optimize log_page_size and log_page_bits into constants. | |
465 | */ | |
466 | log_page_bits = generic_ffs(log_page_size) - 1; | |
3bd1f4a1 | 467 | size &= ~(s64)(log_page_size - 1); |
1da177e4 LT |
468 | /* |
469 | * Ensure the log file is big enough to store at least the two restart | |
470 | * pages and the minimum number of log record pages. | |
471 | */ | |
472 | if (size < log_page_size * 2 || (size - log_page_size * 2) >> | |
473 | log_page_bits < MinLogRecordPages) { | |
474 | ntfs_error(vol->sb, "$LogFile is too small."); | |
475 | return FALSE; | |
476 | } | |
477 | /* | |
478 | * Read through the file looking for a restart page. Since the restart | |
479 | * page header is at the beginning of a page we only need to search at | |
480 | * what could be the beginning of a page (for each page size) rather | |
481 | * than scanning the whole file byte by byte. If all potential places | |
482 | * contain empty and uninitialzed records, the log file can be assumed | |
483 | * to be empty. | |
484 | */ | |
485 | for (pos = 0; pos < size; pos <<= 1) { | |
486 | pgoff_t idx = pos >> PAGE_CACHE_SHIFT; | |
487 | if (!page || page->index != idx) { | |
488 | if (page) | |
489 | ntfs_unmap_page(page); | |
490 | page = ntfs_map_page(mapping, idx); | |
491 | if (IS_ERR(page)) { | |
492 | ntfs_error(vol->sb, "Error mapping $LogFile " | |
493 | "page (index %lu).", idx); | |
494 | return FALSE; | |
495 | } | |
496 | } | |
497 | kaddr = (u8*)page_address(page) + (pos & ~PAGE_CACHE_MASK); | |
498 | /* | |
499 | * A non-empty block means the logfile is not empty while an | |
500 | * empty block after a non-empty block has been encountered | |
501 | * means we are done. | |
502 | */ | |
503 | if (!ntfs_is_empty_recordp((le32*)kaddr)) | |
504 | logfile_is_empty = FALSE; | |
505 | else if (!logfile_is_empty) | |
506 | break; | |
507 | /* | |
508 | * A log record page means there cannot be a restart page after | |
509 | * this so no need to continue searching. | |
510 | */ | |
511 | if (ntfs_is_rcrd_recordp((le32*)kaddr)) | |
512 | break; | |
513 | /* | |
514 | * A modified by chkdsk restart page means we cannot handle | |
515 | * this log file. | |
516 | */ | |
517 | if (ntfs_is_chkd_recordp((le32*)kaddr)) { | |
518 | ntfs_error(vol->sb, "$LogFile has been modified by " | |
519 | "chkdsk. Mount this volume in " | |
520 | "Windows."); | |
521 | goto err_out; | |
522 | } | |
523 | /* If not a restart page, continue. */ | |
524 | if (!ntfs_is_rstr_recordp((le32*)kaddr)) { | |
525 | /* Skip to the minimum page size for the next one. */ | |
526 | if (!pos) | |
527 | pos = NTFS_BLOCK_SIZE >> 1; | |
528 | continue; | |
529 | } | |
530 | /* We now know we have a restart page. */ | |
531 | if (!pos) { | |
532 | rstr1_found = TRUE; | |
533 | rstr1_pos = pos; | |
534 | } else { | |
535 | if (rstr2_found) { | |
536 | ntfs_error(vol->sb, "Found more than two " | |
537 | "restart pages in $LogFile."); | |
538 | goto err_out; | |
539 | } | |
540 | rstr2_found = TRUE; | |
541 | rstr2_pos = pos; | |
542 | } | |
543 | /* | |
544 | * Check the restart page for consistency and get a copy of the | |
545 | * complete multi sector transfer deprotected restart page. | |
546 | */ | |
547 | if (!ntfs_check_and_load_restart_page(log_vi, | |
548 | (RESTART_PAGE_HEADER*)kaddr, pos, | |
549 | !pos ? &rstr1_ph : &rstr2_ph)) { | |
550 | /* Error output already done inside the function. */ | |
551 | goto err_out; | |
552 | } | |
553 | /* | |
554 | * We have a valid restart page. The next one must be after | |
555 | * a whole system page size as specified by the valid restart | |
556 | * page. | |
557 | */ | |
558 | if (!pos) | |
559 | pos = le32_to_cpu(rstr1_ph->system_page_size) >> 1; | |
560 | } | |
561 | if (page) { | |
562 | ntfs_unmap_page(page); | |
563 | page = NULL; | |
564 | } | |
565 | if (logfile_is_empty) { | |
566 | NVolSetLogFileEmpty(vol); | |
567 | is_empty: | |
568 | ntfs_debug("Done. ($LogFile is empty.)"); | |
569 | return TRUE; | |
570 | } | |
571 | if (!rstr1_found || !rstr2_found) { | |
572 | ntfs_error(vol->sb, "Did not find two restart pages in " | |
573 | "$LogFile."); | |
574 | goto err_out; | |
575 | } | |
576 | /* | |
577 | * The two restart areas must be identical except for the update | |
578 | * sequence number. | |
579 | */ | |
580 | ofs = le16_to_cpu(rstr1_ph->usa_ofs); | |
581 | if (memcmp(rstr1_ph, rstr2_ph, ofs) || (ofs += sizeof(u16), | |
582 | memcmp((u8*)rstr1_ph + ofs, (u8*)rstr2_ph + ofs, | |
583 | le32_to_cpu(rstr1_ph->system_page_size) - ofs))) { | |
584 | ntfs_error(vol->sb, "The two restart pages in $LogFile do not " | |
585 | "match."); | |
586 | goto err_out; | |
587 | } | |
588 | ntfs_free(rstr1_ph); | |
589 | ntfs_free(rstr2_ph); | |
590 | /* All consistency checks passed. */ | |
591 | ntfs_debug("Done."); | |
592 | return TRUE; | |
593 | err_out: | |
594 | if (page) | |
595 | ntfs_unmap_page(page); | |
596 | if (rstr1_ph) | |
597 | ntfs_free(rstr1_ph); | |
598 | if (rstr2_ph) | |
599 | ntfs_free(rstr2_ph); | |
600 | return FALSE; | |
601 | } | |
602 | ||
603 | /** | |
604 | * ntfs_is_logfile_clean - check in the journal if the volume is clean | |
605 | * @log_vi: struct inode of loaded journal $LogFile to check | |
606 | * | |
607 | * Analyze the $LogFile journal and return TRUE if it indicates the volume was | |
608 | * shutdown cleanly and FALSE if not. | |
609 | * | |
610 | * At present we only look at the two restart pages and ignore the log record | |
611 | * pages. This is a little bit crude in that there will be a very small number | |
612 | * of cases where we think that a volume is dirty when in fact it is clean. | |
613 | * This should only affect volumes that have not been shutdown cleanly but did | |
614 | * not have any pending, non-check-pointed i/o, i.e. they were completely idle | |
615 | * at least for the five seconds preceeding the unclean shutdown. | |
616 | * | |
617 | * This function assumes that the $LogFile journal has already been consistency | |
618 | * checked by a call to ntfs_check_logfile() and in particular if the $LogFile | |
619 | * is empty this function requires that NVolLogFileEmpty() is true otherwise an | |
620 | * empty volume will be reported as dirty. | |
621 | */ | |
622 | BOOL ntfs_is_logfile_clean(struct inode *log_vi) | |
623 | { | |
624 | ntfs_volume *vol = NTFS_SB(log_vi->i_sb); | |
625 | struct page *page; | |
626 | RESTART_PAGE_HEADER *rp; | |
627 | RESTART_AREA *ra; | |
628 | ||
629 | ntfs_debug("Entering."); | |
630 | /* An empty $LogFile must have been clean before it got emptied. */ | |
631 | if (NVolLogFileEmpty(vol)) { | |
632 | ntfs_debug("Done. ($LogFile is empty.)"); | |
633 | return TRUE; | |
634 | } | |
635 | /* | |
636 | * Read the first restart page. It will be possibly incomplete and | |
637 | * will not be multi sector transfer deprotected but we only need the | |
638 | * first NTFS_BLOCK_SIZE bytes so it does not matter. | |
639 | */ | |
640 | page = ntfs_map_page(log_vi->i_mapping, 0); | |
641 | if (IS_ERR(page)) { | |
642 | ntfs_error(vol->sb, "Error mapping $LogFile page (index 0)."); | |
643 | return FALSE; | |
644 | } | |
645 | rp = (RESTART_PAGE_HEADER*)page_address(page); | |
646 | if (!ntfs_is_rstr_record(rp->magic)) { | |
647 | ntfs_error(vol->sb, "No restart page found at offset zero in " | |
648 | "$LogFile. This is probably a bug in that " | |
649 | "the $LogFile should have been consistency " | |
650 | "checked before calling this function."); | |
651 | goto err_out; | |
652 | } | |
653 | ra = (RESTART_AREA*)((u8*)rp + le16_to_cpu(rp->restart_area_offset)); | |
654 | /* | |
655 | * If the $LogFile has active clients, i.e. it is open, and we do not | |
656 | * have the RESTART_VOLUME_IS_CLEAN bit set in the restart area flags, | |
657 | * we assume there was an unclean shutdown. | |
658 | */ | |
659 | if (ra->client_in_use_list != LOGFILE_NO_CLIENT && | |
660 | !(ra->flags & RESTART_VOLUME_IS_CLEAN)) { | |
661 | ntfs_debug("Done. $LogFile indicates a dirty shutdown."); | |
662 | goto err_out; | |
663 | } | |
664 | ntfs_unmap_page(page); | |
665 | /* $LogFile indicates a clean shutdown. */ | |
666 | ntfs_debug("Done. $LogFile indicates a clean shutdown."); | |
667 | return TRUE; | |
668 | err_out: | |
669 | ntfs_unmap_page(page); | |
670 | return FALSE; | |
671 | } | |
672 | ||
673 | /** | |
674 | * ntfs_empty_logfile - empty the contents of the $LogFile journal | |
675 | * @log_vi: struct inode of loaded journal $LogFile to empty | |
676 | * | |
677 | * Empty the contents of the $LogFile journal @log_vi and return TRUE on | |
678 | * success and FALSE on error. | |
679 | * | |
680 | * This function assumes that the $LogFile journal has already been consistency | |
681 | * checked by a call to ntfs_check_logfile() and that ntfs_is_logfile_clean() | |
682 | * has been used to ensure that the $LogFile is clean. | |
683 | */ | |
684 | BOOL ntfs_empty_logfile(struct inode *log_vi) | |
685 | { | |
686 | ntfs_volume *vol = NTFS_SB(log_vi->i_sb); | |
687 | ||
688 | ntfs_debug("Entering."); | |
689 | if (!NVolLogFileEmpty(vol)) { | |
690 | int err; | |
691 | ||
66129f88 AA |
692 | err = ntfs_attr_set(NTFS_I(log_vi), 0, i_size_read(log_vi), |
693 | 0xff); | |
1da177e4 LT |
694 | if (unlikely(err)) { |
695 | ntfs_error(vol->sb, "Failed to fill $LogFile with " | |
696 | "0xff bytes (error code %i).", err); | |
697 | return FALSE; | |
698 | } | |
699 | /* Set the flag so we do not have to do it again on remount. */ | |
700 | NVolSetLogFileEmpty(vol); | |
701 | } | |
702 | ntfs_debug("Done."); | |
703 | return TRUE; | |
704 | } | |
705 | ||
706 | #endif /* NTFS_RW */ |