/** * logfile.c - NTFS journal handling. Originated from the Linux-NTFS project. * * Copyright (c) 2002-2005 Anton Altaparmakov * Copyright (c) 2005 Yura Pakhuchiy * Copyright (c) 2005-2009 Szabolcs Szakacsits * * This program/include file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program/include file is distributed in the hope that it will be * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (in the main directory of the NTFS-3G * distribution in the file COPYING); if not, write to the Free Software * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifdef HAVE_STDLIB_H #include #endif #ifdef HAVE_STRING_H #include #endif #ifdef HAVE_ERRNO_H #include #endif #include "attrib.h" #include "debug.h" #include "logfile.h" #include "volume.h" #include "mst.h" #include "logging.h" #include "misc.h" /** * ntfs_check_restart_page_header - check the page header for consistency * @rp: restart page header to check * @pos: position in logfile at which the restart page header resides * * Check the restart page header @rp for consistency and return TRUE if it is * consistent and FALSE otherwise. * * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not * require the full restart page. */ static BOOL ntfs_check_restart_page_header( RESTART_PAGE_HEADER *rp, s64 pos ) { u32 logfile_system_page_size, logfile_log_page_size; u16 ra_ofs, usa_count, usa_ofs, usa_end = 0; BOOL have_usa = TRUE; ntfs_log_trace( "Entering.\n" ); /* * If the system or log page sizes are smaller than the ntfs block size * or either is not a power of 2 we cannot handle this log file. */ logfile_system_page_size = le32_to_cpu( rp->system_page_size ); logfile_log_page_size = le32_to_cpu( rp->log_page_size ); if ( logfile_system_page_size < NTFS_BLOCK_SIZE || logfile_log_page_size < NTFS_BLOCK_SIZE || logfile_system_page_size & ( logfile_system_page_size - 1 ) || logfile_log_page_size & ( logfile_log_page_size - 1 ) ) { ntfs_log_error( "$LogFile uses unsupported page size.\n" ); return FALSE; } /* * We must be either at !pos (1st restart page) or at pos = system page * size (2nd restart page). */ if ( pos && pos != logfile_system_page_size ) { ntfs_log_error( "Found restart area in incorrect " "position in $LogFile.\n" ); return FALSE; } /* We only know how to handle version 1.1. */ if ( sle16_to_cpu( rp->major_ver ) != 1 || sle16_to_cpu( rp->minor_ver ) != 1 ) { ntfs_log_error( "$LogFile version %i.%i is not " "supported. (This driver supports version " "1.1 only.)\n", ( int )sle16_to_cpu( rp->major_ver ), ( int )sle16_to_cpu( rp->minor_ver ) ); return FALSE; } /* * If chkdsk has been run the restart page may not be protected by an * update sequence array. */ if ( ntfs_is_chkd_record( rp->magic ) && !le16_to_cpu( rp->usa_count ) ) { have_usa = FALSE; goto skip_usa_checks; } /* Verify the size of the update sequence array. */ usa_count = 1 + ( logfile_system_page_size >> NTFS_BLOCK_SIZE_BITS ); if ( usa_count != le16_to_cpu( rp->usa_count ) ) { ntfs_log_error( "$LogFile restart page specifies " "inconsistent update sequence array count.\n" ); return FALSE; } /* Verify the position of the update sequence array. */ usa_ofs = le16_to_cpu( rp->usa_ofs ); usa_end = usa_ofs + usa_count * sizeof( u16 ); if ( usa_ofs < sizeof( RESTART_PAGE_HEADER ) || usa_end > NTFS_BLOCK_SIZE - sizeof( u16 ) ) { ntfs_log_error( "$LogFile restart page specifies " "inconsistent update sequence array offset.\n" ); return FALSE; } skip_usa_checks: /* * Verify the position of the restart area. It must be: * - aligned to 8-byte boundary, * - after the update sequence array, and * - within the system page size. */ ra_ofs = le16_to_cpu( rp->restart_area_offset ); if ( ra_ofs & 7 || ( have_usa ? ra_ofs < usa_end : ra_ofs < sizeof( RESTART_PAGE_HEADER ) ) || ra_ofs > logfile_system_page_size ) { ntfs_log_error( "$LogFile restart page specifies " "inconsistent restart area offset.\n" ); return FALSE; } /* * Only restart pages modified by chkdsk are allowed to have chkdsk_lsn * set. */ if ( !ntfs_is_chkd_record( rp->magic ) && sle64_to_cpu( rp->chkdsk_lsn ) ) { ntfs_log_error( "$LogFile restart page is not modified " "by chkdsk but a chkdsk LSN is specified.\n" ); return FALSE; } ntfs_log_trace( "Done.\n" ); return TRUE; } /** * ntfs_check_restart_area - check the restart area for consistency * @rp: restart page whose restart area to check * * Check the restart area of the restart page @rp for consistency and return * TRUE if it is consistent and FALSE otherwise. * * This function assumes that the restart page header has already been * consistency checked. * * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not * require the full restart page. */ static BOOL ntfs_check_restart_area( RESTART_PAGE_HEADER *rp ) { u64 file_size; RESTART_AREA *ra; u16 ra_ofs, ra_len, ca_ofs; u8 fs_bits; ntfs_log_trace( "Entering.\n" ); ra_ofs = le16_to_cpu( rp->restart_area_offset ); ra = ( RESTART_AREA* )( ( u8* )rp + ra_ofs ); /* * Everything before ra->file_size must be before the first word * protected by an update sequence number. This ensures that it is * safe to access ra->client_array_offset. */ if ( ra_ofs + offsetof( RESTART_AREA, file_size ) > NTFS_BLOCK_SIZE - sizeof( u16 ) ) { ntfs_log_error( "$LogFile restart area specifies " "inconsistent file offset.\n" ); return FALSE; } /* * Now that we can access ra->client_array_offset, make sure everything * up to the log client array is before the first word protected by an * update sequence number. This ensures we can access all of the * restart area elements safely. Also, the client array offset must be * aligned to an 8-byte boundary. */ ca_ofs = le16_to_cpu( ra->client_array_offset ); if ( ( ( ca_ofs + 7 ) & ~7 ) != ca_ofs || ra_ofs + ca_ofs > ( u16 )( NTFS_BLOCK_SIZE - sizeof( u16 ) ) ) { ntfs_log_error( "$LogFile restart area specifies " "inconsistent client array offset.\n" ); return FALSE; } /* * The restart area must end within the system page size both when * calculated manually and as specified by ra->restart_area_length. * Also, the calculated length must not exceed the specified length. */ ra_len = ca_ofs + le16_to_cpu( ra->log_clients ) * sizeof( LOG_CLIENT_RECORD ); if ( ( u32 )( ra_ofs + ra_len ) > le32_to_cpu( rp->system_page_size ) || ( u32 )( ra_ofs + le16_to_cpu( ra->restart_area_length ) ) > le32_to_cpu( rp->system_page_size ) || ra_len > le16_to_cpu( ra->restart_area_length ) ) { ntfs_log_error( "$LogFile restart area is out of bounds " "of the system page size specified by the " "restart page header and/or the specified " "restart area length is inconsistent.\n" ); return FALSE; } /* * The ra->client_free_list and ra->client_in_use_list must be either * LOGFILE_NO_CLIENT or less than ra->log_clients or they are * overflowing the client array. */ if ( ( ra->client_free_list != LOGFILE_NO_CLIENT && le16_to_cpu( ra->client_free_list ) >= le16_to_cpu( ra->log_clients ) ) || ( ra->client_in_use_list != LOGFILE_NO_CLIENT && le16_to_cpu( ra->client_in_use_list ) >= le16_to_cpu( ra->log_clients ) ) ) { ntfs_log_error( "$LogFile restart area specifies " "overflowing client free and/or in use lists.\n" ); return FALSE; } /* * Check ra->seq_number_bits against ra->file_size for consistency. * We cannot just use ffs() because the file size is not a power of 2. */ file_size = ( u64 )sle64_to_cpu( ra->file_size ); fs_bits = 0; while ( file_size ) { file_size >>= 1; fs_bits++; } if ( le32_to_cpu( ra->seq_number_bits ) != ( u32 )( 67 - fs_bits ) ) { ntfs_log_error( "$LogFile restart area specifies " "inconsistent sequence number bits.\n" ); return FALSE; } /* The log record header length must be a multiple of 8. */ if ( ( ( le16_to_cpu( ra->log_record_header_length ) + 7 ) & ~7 ) != le16_to_cpu( ra->log_record_header_length ) ) { ntfs_log_error( "$LogFile restart area specifies " "inconsistent log record header length.\n" ); return FALSE; } /* Ditto for the log page data offset. */ if ( ( ( le16_to_cpu( ra->log_page_data_offset ) + 7 ) & ~7 ) != le16_to_cpu( ra->log_page_data_offset ) ) { ntfs_log_error( "$LogFile restart area specifies " "inconsistent log page data offset.\n" ); return FALSE; } ntfs_log_trace( "Done.\n" ); return TRUE; } /** * ntfs_check_log_client_array - check the log client array for consistency * @rp: restart page whose log client array to check * * Check the log client array of the restart page @rp for consistency and * return TRUE if it is consistent and FALSE otherwise. * * This function assumes that the restart page header and the restart area have * already been consistency checked. * * Unlike ntfs_check_restart_page_header() and ntfs_check_restart_area(), this * function needs @rp->system_page_size bytes in @rp, i.e. it requires the full * restart page and the page must be multi sector transfer deprotected. */ static BOOL ntfs_check_log_client_array( RESTART_PAGE_HEADER *rp ) { RESTART_AREA *ra; LOG_CLIENT_RECORD *ca, *cr; u16 nr_clients, idx; BOOL in_free_list, idx_is_first; ntfs_log_trace( "Entering.\n" ); ra = ( RESTART_AREA* )( ( u8* )rp + le16_to_cpu( rp->restart_area_offset ) ); ca = ( LOG_CLIENT_RECORD* )( ( u8* )ra + le16_to_cpu( ra->client_array_offset ) ); /* * Check the ra->client_free_list first and then check the * ra->client_in_use_list. Check each of the log client records in * each of the lists and check that the array does not overflow the * ra->log_clients value. Also keep track of the number of records * visited as there cannot be more than ra->log_clients records and * that way we detect eventual loops in within a list. */ nr_clients = le16_to_cpu( ra->log_clients ); idx = le16_to_cpu( ra->client_free_list ); in_free_list = TRUE; check_list: for ( idx_is_first = TRUE; idx != LOGFILE_NO_CLIENT_CPU; nr_clients--, idx = le16_to_cpu( cr->next_client ) ) { if ( !nr_clients || idx >= le16_to_cpu( ra->log_clients ) ) goto err_out; /* Set @cr to the current log client record. */ cr = ca + idx; /* The first log client record must not have a prev_client. */ if ( idx_is_first ) { if ( cr->prev_client != LOGFILE_NO_CLIENT ) goto err_out; idx_is_first = FALSE; } } /* Switch to and check the in use list if we just did the free list. */ if ( in_free_list ) { in_free_list = FALSE; idx = le16_to_cpu( ra->client_in_use_list ); goto check_list; } ntfs_log_trace( "Done.\n" ); return TRUE; err_out: ntfs_log_error( "$LogFile log client array is corrupt.\n" ); return FALSE; } /** * ntfs_check_and_load_restart_page - check the restart page for consistency * @log_na: opened ntfs attribute for journal $LogFile * @rp: restart page to check * @pos: position in @log_na at which the restart page resides * @wrp: [OUT] copy of the multi sector transfer deprotected restart page * @lsn: [OUT] set to the current logfile lsn on success * * Check the restart page @rp for consistency and return 0 if it is consistent * and errno otherwise. The restart page may have been modified by chkdsk in * which case its magic is CHKD instead of RSTR. * * This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not * require the full restart page. * * If @wrp is not NULL, on success, *@wrp will point to a buffer containing a * copy of the complete multi sector transfer deprotected page. On failure, * *@wrp is undefined. * * Similarly, if @lsn is not NULL, on success *@lsn will be set to the current * logfile lsn according to this restart page. On failure, *@lsn is undefined. * * The following error codes are defined: * EINVAL - The restart page is inconsistent. * ENOMEM - Not enough memory to load the restart page. * EIO - Failed to reading from $LogFile. */ static int ntfs_check_and_load_restart_page( ntfs_attr *log_na, RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp, LSN *lsn ) { RESTART_AREA *ra; RESTART_PAGE_HEADER *trp; int err; ntfs_log_trace( "Entering.\n" ); /* Check the restart page header for consistency. */ if ( !ntfs_check_restart_page_header( rp, pos ) ) { /* Error output already done inside the function. */ return EINVAL; } /* Check the restart area for consistency. */ if ( !ntfs_check_restart_area( rp ) ) { /* Error output already done inside the function. */ return EINVAL; } ra = ( RESTART_AREA* )( ( u8* )rp + le16_to_cpu( rp->restart_area_offset ) ); /* * Allocate a buffer to store the whole restart page so we can multi * sector transfer deprotect it. */ trp = ntfs_malloc( le32_to_cpu( rp->system_page_size ) ); if ( !trp ) return errno; /* * Read the whole of the restart page into the buffer. If it fits * completely inside @rp, just copy it from there. Otherwise read it * from disk. */ if ( le32_to_cpu( rp->system_page_size ) <= NTFS_BLOCK_SIZE ) memcpy( trp, rp, le32_to_cpu( rp->system_page_size ) ); else if ( ntfs_attr_pread( log_na, pos, le32_to_cpu( rp->system_page_size ), trp ) != le32_to_cpu( rp->system_page_size ) ) { err = errno; ntfs_log_error( "Failed to read whole restart page into the " "buffer.\n" ); if ( err != ENOMEM ) err = EIO; goto err_out; } /* * Perform the multi sector transfer deprotection on the buffer if the * restart page is protected. */ if ( ( !ntfs_is_chkd_record( trp->magic ) || le16_to_cpu( trp->usa_count ) ) && ntfs_mst_post_read_fixup( ( NTFS_RECORD* )trp, le32_to_cpu( rp->system_page_size ) ) ) { /* * A multi sector tranfer error was detected. We only need to * abort if the restart page contents exceed the multi sector * transfer fixup of the first sector. */ if ( le16_to_cpu( rp->restart_area_offset ) + le16_to_cpu( ra->restart_area_length ) > NTFS_BLOCK_SIZE - ( int )sizeof( u16 ) ) { ntfs_log_error( "Multi sector transfer error " "detected in $LogFile restart page.\n" ); err = EINVAL; goto err_out; } } /* * If the restart page is modified by chkdsk or there are no active * logfile clients, the logfile is consistent. Otherwise, need to * check the log client records for consistency, too. */ err = 0; if ( ntfs_is_rstr_record( rp->magic ) && ra->client_in_use_list != LOGFILE_NO_CLIENT ) { if ( !ntfs_check_log_client_array( trp ) ) { err = EINVAL; goto err_out; } } if ( lsn ) { if ( ntfs_is_rstr_record( rp->magic ) ) *lsn = sle64_to_cpu( ra->current_lsn ); else /* if (ntfs_is_chkd_record(rp->magic)) */ *lsn = sle64_to_cpu( rp->chkdsk_lsn ); } ntfs_log_trace( "Done.\n" ); if ( wrp ) *wrp = trp; else { err_out: free( trp ); } return err; } /** * ntfs_check_logfile - check in the journal if the volume is consistent * @log_na: ntfs attribute of loaded journal $LogFile to check * @rp: [OUT] on success this is a copy of the current restart page * * Check the $LogFile journal for consistency and return TRUE if it is * consistent and FALSE if not. On success, the current restart page is * returned in *@rp. Caller must call ntfs_free(*@rp) when finished with it. * * At present we only check the two restart pages and ignore the log record * pages. * * Note that the MstProtected flag is not set on the $LogFile inode and hence * when reading pages they are not deprotected. This is because we do not know * if the $LogFile was created on a system with a different page size to ours * yet and mst deprotection would fail if our page size is smaller. */ BOOL ntfs_check_logfile( ntfs_attr *log_na, RESTART_PAGE_HEADER **rp ) { s64 size, pos; LSN rstr1_lsn, rstr2_lsn; ntfs_volume *vol = log_na->ni->vol; u8 *kaddr = NULL; RESTART_PAGE_HEADER *rstr1_ph = NULL; RESTART_PAGE_HEADER *rstr2_ph = NULL; int log_page_size, log_page_mask, err; BOOL logfile_is_empty = TRUE; u8 log_page_bits; ntfs_log_trace( "Entering.\n" ); /* An empty $LogFile must have been clean before it got emptied. */ if ( NVolLogFileEmpty( vol ) ) goto is_empty; size = log_na->data_size; /* Make sure the file doesn't exceed the maximum allowed size. */ if ( size > ( s64 )MaxLogFileSize ) size = MaxLogFileSize; log_page_size = DefaultLogPageSize; log_page_mask = log_page_size - 1; /* * Use generic_ffs() instead of ffs() to enable the compiler to * optimize log_page_size and log_page_bits into constants. */ log_page_bits = ffs( log_page_size ) - 1; size &= ~( log_page_size - 1 ); /* * Ensure the log file is big enough to store at least the two restart * pages and the minimum number of log record pages. */ if ( size < log_page_size * 2 || ( size - log_page_size * 2 ) >> log_page_bits < MinLogRecordPages ) { ntfs_log_error( "$LogFile is too small.\n" ); return FALSE; } /* Allocate memory for restart page. */ kaddr = ntfs_malloc( NTFS_BLOCK_SIZE ); if ( !kaddr ) return FALSE; /* * Read through the file looking for a restart page. Since the restart * page header is at the beginning of a page we only need to search at * what could be the beginning of a page (for each page size) rather * than scanning the whole file byte by byte. If all potential places * contain empty and uninitialized records, the log file can be assumed * to be empty. */ for ( pos = 0; pos < size; pos <<= 1 ) { /* * Read first NTFS_BLOCK_SIZE bytes of potential restart page. */ if ( ntfs_attr_pread( log_na, pos, NTFS_BLOCK_SIZE, kaddr ) != NTFS_BLOCK_SIZE ) { ntfs_log_error( "Failed to read first NTFS_BLOCK_SIZE " "bytes of potential restart page.\n" ); goto err_out; } /* * A non-empty block means the logfile is not empty while an * empty block after a non-empty block has been encountered * means we are done. */ if ( !ntfs_is_empty_recordp( ( le32* )kaddr ) ) logfile_is_empty = FALSE; else if ( !logfile_is_empty ) break; /* * A log record page means there cannot be a restart page after * this so no need to continue searching. */ if ( ntfs_is_rcrd_recordp( ( le32* )kaddr ) ) break; /* If not a (modified by chkdsk) restart page, continue. */ if ( !ntfs_is_rstr_recordp( ( le32* )kaddr ) && !ntfs_is_chkd_recordp( ( le32* )kaddr ) ) { if ( !pos ) pos = NTFS_BLOCK_SIZE >> 1; continue; } /* * Check the (modified by chkdsk) restart page for consistency * and get a copy of the complete multi sector transfer * deprotected restart page. */ err = ntfs_check_and_load_restart_page( log_na, ( RESTART_PAGE_HEADER* )kaddr, pos, !rstr1_ph ? &rstr1_ph : &rstr2_ph, !rstr1_ph ? &rstr1_lsn : &rstr2_lsn ); if ( !err ) { /* * If we have now found the first (modified by chkdsk) * restart page, continue looking for the second one. */ if ( !pos ) { pos = NTFS_BLOCK_SIZE >> 1; continue; } /* * We have now found the second (modified by chkdsk) * restart page, so we can stop looking. */ break; } /* * Error output already done inside the function. Note, we do * not abort if the restart page was invalid as we might still * find a valid one further in the file. */ if ( err != EINVAL ) goto err_out; /* Continue looking. */ if ( !pos ) pos = NTFS_BLOCK_SIZE >> 1; } if ( kaddr ) { free( kaddr ); kaddr = NULL; } if ( logfile_is_empty ) { NVolSetLogFileEmpty( vol ); is_empty: ntfs_log_trace( "Done. ($LogFile is empty.)\n" ); return TRUE; } if ( !rstr1_ph ) { if ( rstr2_ph ) ntfs_log_error( "BUG: rstr2_ph isn't NULL!\n" ); ntfs_log_error( "Did not find any restart pages in " "$LogFile and it was not empty.\n" ); return FALSE; } /* If both restart pages were found, use the more recent one. */ if ( rstr2_ph ) { /* * If the second restart area is more recent, switch to it. * Otherwise just throw it away. */ if ( rstr2_lsn > rstr1_lsn ) { ntfs_log_debug( "Using second restart page as it is more " "recent.\n" ); free( rstr1_ph ); rstr1_ph = rstr2_ph; /* rstr1_lsn = rstr2_lsn; */ } else { ntfs_log_debug( "Using first restart page as it is more " "recent.\n" ); free( rstr2_ph ); } rstr2_ph = NULL; } /* All consistency checks passed. */ if ( rp ) *rp = rstr1_ph; else free( rstr1_ph ); ntfs_log_trace( "Done.\n" ); return TRUE; err_out: free( kaddr ); free( rstr1_ph ); free( rstr2_ph ); return FALSE; } /** * ntfs_is_logfile_clean - check in the journal if the volume is clean * @log_na: ntfs attribute of loaded journal $LogFile to check * @rp: copy of the current restart page * * Analyze the $LogFile journal and return TRUE if it indicates the volume was * shutdown cleanly and FALSE if not. * * At present we only look at the two restart pages and ignore the log record * pages. This is a little bit crude in that there will be a very small number * of cases where we think that a volume is dirty when in fact it is clean. * This should only affect volumes that have not been shutdown cleanly but did * not have any pending, non-check-pointed i/o, i.e. they were completely idle * at least for the five seconds preceding the unclean shutdown. * * This function assumes that the $LogFile journal has already been consistency * checked by a call to ntfs_check_logfile() and in particular if the $LogFile * is empty this function requires that NVolLogFileEmpty() is true otherwise an * empty volume will be reported as dirty. */ BOOL ntfs_is_logfile_clean( ntfs_attr *log_na, RESTART_PAGE_HEADER *rp ) { RESTART_AREA *ra; ntfs_log_trace( "Entering.\n" ); /* An empty $LogFile must have been clean before it got emptied. */ if ( NVolLogFileEmpty( log_na->ni->vol ) ) { ntfs_log_trace( "$LogFile is empty\n" ); return TRUE; } if ( !rp ) { ntfs_log_error( "Restart page header is NULL\n" ); return FALSE; } if ( !ntfs_is_rstr_record( rp->magic ) && !ntfs_is_chkd_record( rp->magic ) ) { ntfs_log_error( "Restart page buffer is invalid\n" ); return FALSE; } ra = ( RESTART_AREA* )( ( u8* )rp + le16_to_cpu( rp->restart_area_offset ) ); /* * If the $LogFile has active clients, i.e. it is open, and we do not * have the RESTART_VOLUME_IS_CLEAN bit set in the restart area flags, * we assume there was an unclean shutdown. */ if ( ra->client_in_use_list != LOGFILE_NO_CLIENT && !( ra->flags & RESTART_VOLUME_IS_CLEAN ) ) { ntfs_log_error( "The disk contains an unclean file system (%d, " "%d).\n", le16_to_cpu( ra->client_in_use_list ), le16_to_cpu( ra->flags ) ); return FALSE; } /* $LogFile indicates a clean shutdown. */ ntfs_log_trace( "$LogFile indicates a clean shutdown\n" ); return TRUE; } /** * ntfs_empty_logfile - empty the contents of the $LogFile journal * @na: ntfs attribute of journal $LogFile to empty * * Empty the contents of the $LogFile journal @na and return 0 on success and * -1 on error. * * This function assumes that the $LogFile journal has already been consistency * checked by a call to ntfs_check_logfile() and that ntfs_is_logfile_clean() * has been used to ensure that the $LogFile is clean. */ int ntfs_empty_logfile( ntfs_attr *na ) { s64 pos, count; char buf[NTFS_BUF_SIZE]; ntfs_log_trace( "Entering.\n" ); if ( NVolLogFileEmpty( na->ni->vol ) ) return 0; if ( !NAttrNonResident( na ) ) { errno = EIO; ntfs_log_perror( "Resident $LogFile $DATA attribute" ); return -1; } memset( buf, -1, NTFS_BUF_SIZE ); pos = 0; while ( ( count = na->data_size - pos ) > 0 ) { if ( count > NTFS_BUF_SIZE ) count = NTFS_BUF_SIZE; count = ntfs_attr_pwrite( na, pos, count, buf ); if ( count <= 0 ) { ntfs_log_perror( "Failed to reset $LogFile" ); if ( count != -1 ) errno = EIO; return -1; } pos += count; } NVolSetLogFileEmpty( na->ni->vol ); return 0; }