fs/ntfs/logfile.c

   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:         $LogFile inode to which the restart page header belongs
  29  * @rp:         restart page header to check
  30  * @pos:        position in @vi at which the restart page header resides
  31  *
  32  * Check the restart page header @rp for consistency and return 'true' if it is
  33  * consistent and 'false' otherwise.
  34  *
  35  * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
  36  * require the full restart page.
  37  */
  38 static bool ntfs_check_restart_page_header(struct inode *vi,
  39                 RESTART_PAGE_HEADER *rp, s64 pos)
  40 {
  41         u32 logfile_system_page_size, logfile_log_page_size;
  42         u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
  43         bool have_usa = true;
  44
  45         ntfs_debug("Entering.");
  46         /*
  47          * If the system or log page sizes are smaller than the ntfs block size
  48          * or either is not a power of 2 we cannot handle this log file.
  49          */
  50         logfile_system_page_size = le32_to_cpu(rp->system_page_size);
  51         logfile_log_page_size = le32_to_cpu(rp->log_page_size);
  52         if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
  53                         logfile_log_page_size < NTFS_BLOCK_SIZE ||
  54                         logfile_system_page_size &
  55                         (logfile_system_page_size - 1) ||
  56                         !is_power_of_2(logfile_log_page_size)) {
  57                 ntfs_error(vi->i_sb, "$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         }
 102 skip_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:         $LogFile inode to which the restart page belongs
 133  * @rp:         restart page whose restart area to check
 134  *
 135  * Check the restart area of the restart page @rp for consistency and return
 136  * 'true' if it is consistent and 'false' otherwise.
 137  *
 138  * This function assumes that the restart page header has already been
 139  * consistency checked.
 140  *
 141  * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
 142  * require the full restart page.
 143  */
 144 static bool ntfs_check_restart_area(struct inode *vi, RESTART_PAGE_HEADER *rp)
 145 {
 146         u64 file_size;
 147         RESTART_AREA *ra;
 148         u16 ra_ofs, ra_len, ca_ofs;
 149         u8 fs_bits;
 150
 151         ntfs_debug("Entering.");
 152         ra_ofs = le16_to_cpu(rp->restart_area_offset);
 153         ra = (RESTART_AREA*)((u8*)rp + ra_ofs);
 154         /*
 155          * Everything before ra->file_size must be before the first word
 156          * protected by an update sequence number.  This ensures that it is
 157          * safe to access ra->client_array_offset.
 158          */
 159         if (ra_ofs + offsetof(RESTART_AREA, file_size) >
 160                         NTFS_BLOCK_SIZE - sizeof(u16)) {
 161                 ntfs_error(vi->i_sb, "$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  */
 259 static 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;
 282 check_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;
 304 err_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  */
 336 static 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 {
 448 err_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  */
 471 bool 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);
 603 is_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;
 639 err_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  */
 665 bool 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  */
 712 bool 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)) {
 747 map_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, 0, 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;
 834 io_err:
 835         ntfs_error(sb, "Failed to write buffer.  Unmount and run chkdsk.");
 836         goto dirty_err;
 837 rl_err:
 838         ntfs_error(sb, "Runlist is corrupt.  Unmount and run chkdsk.");
 839 dirty_err:
 840         NVolSetErrors(vol);
 841         err = -EIO;
 842 err:
 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 */