/*
* logfile.c - NTFS kernel journal handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2002-2005 Anton Altaparmakov
*
* 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 Linux-NTFS
* 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 NTFS_RW
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/highmem.h>
#include <linux/buffer_head.h>
#include <linux/bitops.h>
#include "attrib.h"
#include "aops.h"
#include "debug.h"
#include "logfile.h"
#include "malloc.h"
#include "volume.h"
#include "ntfs.h"
/**
* ntfs_check_restart_page_header - check the page header for consistency
* @vi: $LogFile inode to which the restart page header belongs
* @rp: restart page header to check
* @pos: position in @vi at which the restart page header resides
*
* Check the restart page header @rp for consistency and return TRUE if it is
* consistent and FALSE otherwise.
*
* This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
* require the full restart page.
*/
static BOOL ntfs_check_restart_page_header(struct inode *vi,
RESTART_PAGE_HEADER *rp, s64 pos)
{
u32 logfile_system_page_size, logfile_log_page_size;
u16 usa_count, usa_ofs, usa_end, ra_ofs;
ntfs_debug("Entering.");
/*
* If the system or log page sizes are smaller than the ntfs block size
* or either is not a power of 2 we cannot handle this log file.
*/
logfile_system_page_size = le32_to_cpu(rp->system_page_size);
logfile_log_page_size = le32_to_cpu(rp->log_page_size);
if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
logfile_log_page_size < NTFS_BLOCK_SIZE ||
logfile_system_page_size &
(logfile_system_page_size - 1) ||
logfile_log_page_size & (logfile_log_page_size - 1)) {
ntfs_error(vi->i_sb, "$LogFile uses unsupported page size.");
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_error(vi->i_sb, "Found restart area in incorrect "
"position in $LogFile.");
return FALSE;
}
/* We only know how to handle version 1.1. */
if (sle16_to_cpu(rp->major_ver) != 1 ||
sle16_to_cpu(rp->minor_ver) != 1) {
ntfs_error(vi->i_sb, "$LogFile version %i.%i is not "
"supported. (This driver supports version "
"1.1 only.)", (int)sle16_to_cpu(rp->major_ver),
(int)sle16_to_cpu(rp->minor_ver));
return FALSE;
}
/* 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_error(vi->i_sb, "$LogFile restart page specifies "
"inconsistent update sequence array count.");
return FALSE;
}
/* Verify the position of the update sequence array. */
usa_ofs = le16_to_cpu(rp->usa_ofs);
usa_end = usa_ofs + usa_count * sizeof(u16);
if (usa_ofs < sizeof(RESTART_PAGE_HEADER) ||
usa_end > NTFS_BLOCK_SIZE - sizeof(u16)) {
ntfs_error(vi->i_sb, "$LogFile restart page specifies "
"inconsistent update sequence array offset.");
return FALSE;
}
/*
* 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 || ra_ofs < usa_end ||
ra_ofs > logfile_system_page_size) {
ntfs_error(vi->i_sb, "$LogFile restart page specifies "
"inconsistent restart area offset.");
return FALSE;
}
/*
* Only restart pages modified by chkdsk are allowed to have chkdsk_lsn
* set.
*/
if (!ntfs_is_chkd_record(rp->magic) && sle64_to_cpu(rp->chkdsk_lsn)) {
ntfs_error(vi->i_sb, "$LogFile restart page is not modified "
"chkdsk but a chkdsk LSN is specified.");
return FALSE;
}
ntfs_debug("Done.");
return TRUE;
}
/**
* ntfs_check_restart_area - check the restart area for consistency
* @vi: $LogFile inode to which the restart page belongs
* @rp: restart page whose restart area to check
*
* Check the restart area of the restart page @rp for consistency and return
* TRUE if it is consistent and FALSE otherwise.
*
* This function assumes that the restart page header has already been
* consistency checked.
*
* This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
* require the full restart page.
*/
static BOOL ntfs_check_restart_area(struct inode *vi, RESTART_PAGE_HEADER *rp)
{
u64 file_size;
RESTART_AREA *ra;
u16 ra_ofs, ra_len, ca_ofs;
u8 fs_bits;
ntfs_debug("Entering.");
ra_ofs = le16_to_cpu(rp->restart_area_offset);
ra = (RESTART_AREA*)((u8*)rp + ra_ofs);
/*
* Everything before ra->file_size must be before the first word
* protected by an update sequence number. This ensures that it is
* safe to access ra->client_array_offset.
*/
if (ra_ofs + offsetof(RESTART_AREA, file_size) >
NTFS_BLOCK_SIZE - sizeof(u16)) {
ntfs_error(vi->i_sb, "$LogFile restart area specifies "
"inconsistent file offset.");
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 > NTFS_BLOCK_SIZE - sizeof(u16)) {
ntfs_error(vi->i_sb, "$LogFile restart area specifies "
"inconsistent client array offset.");
return FALSE;
}
/*
* The restart area must end within the system page size both when
* calculated manually and as specified by ra->restart_area_length.
* Also, the calculated length must not exceed the specified length.
*/
ra_len = ca_ofs + le16_to_cpu(ra->log_clients) *
sizeof(LOG_CLIENT_RECORD);
if (ra_ofs + ra_len > le32_to_cpu(rp->system_page_size) ||
ra_ofs + le16_to_cpu(ra->restart_area_length) >
le32_to_cpu(rp->system_page_size) ||
ra_len > le16_to_cpu(ra->restart_area_length)) {
ntfs_error(vi->i_sb, "$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.");
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_error(vi->i_sb, "$LogFile restart area specifies "
"overflowing client free and/or in use lists.");
return FALSE;
}
/*
* Check ra->seq_number_bits against ra->file_size for consistency.
* We cannot just use ffs() because the file size is not a power of 2.
*/
file_size = (u64)sle64_to_cpu(ra->file_size);
fs_bits = 0;
while (file_size) {
file_size >>= 1;
fs_bits++;
}
if (le32_to_cpu(ra->seq_number_bits) != 67 - fs_bits) {
ntfs_error(vi->i_sb, "$LogFile restart area specifies "
"inconsistent sequence number bits.");
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_error(vi->i_sb, "$LogFile restart area specifies "
"inconsistent log record header length.");
return FALSE;
}
/* Dito for the log page data offset. */
if (((le16_to_cpu(ra->log_page_data_offset) + 7) & ~7) !=
le16_to_cpu(ra->log_page_data_offset)) {
ntfs_error(vi->i_sb, "$LogFile restart area specifies "
"inconsistent log page data offset.");
return FALSE;
}
ntfs_debug("Done.");
return TRUE;
}
/**
* ntfs_check_log_client_array - check the log client array for consistency
* @vi: $LogFile inode to which the restart page belongs
* @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(struct inode *vi,
RESTART_PAGE_HEADER *rp)
{
RESTART_AREA *ra;
LOG_CLIENT_RECORD *ca, *cr;
u16 nr_clients, idx;
BOOL in_free_list, idx_is_first;
ntfs_debug("Entering.");
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_debug("Done.");
return TRUE;
err_out:
ntfs_error(vi->i_sb, "$LogFile log client array is corrupt.");
return FALSE;
}
/**
* ntfs_check_and_load_restart_page - check the restart page for consistency
* @vi: $LogFile inode to which the restart page belongs
* @rp: restart page to check
* @pos: position in @vi at which the restart page resides
* @wrp: copy of the multi sector transfer deprotected restart page
*
* Check the restart page @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.
*
* 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.
*/
static BOOL ntfs_check_and_load_restart_page(struct inode *vi,
RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp)
{
RESTART_AREA *ra;
RESTART_PAGE_HEADER *trp;
int size;
BOOL ret;
ntfs_debug("Entering.");
/* Check the restart page header for consistency. */
if (!ntfs_check_restart_page_header(vi, rp, pos)) {
/* Error output already done inside the function. */
return FALSE;
}
/* Check the restart area for consistency. */
if (!ntfs_check_restart_area(vi, rp)) {
/* Error output already done inside the function. */
return FALSE;
}
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_nofs(le32_to_cpu(rp->system_page_size));
if (!trp) {
ntfs_error(vi->i_sb, "Failed to allocate memory for $LogFile "
"restart page buffer.");
return FALSE;
}
/*
* Read the whole of the restart page into the buffer. If it fits
* completely inside @rp, just copy it from there. Otherwise map all
* the required pages and copy the data from them.
*/
size = PAGE_CACHE_SIZE - (pos & ~PAGE_CACHE_MASK);
if (size >= le32_to_cpu(rp->system_page_size)) {
memcpy(trp, rp, le32_to_cpu(rp->system_page_size));
} else {
pgoff_t idx;
struct page *page;
int have_read, to_read;
/* First copy what we already have in @rp. */
memcpy(trp, rp, size);
/* Copy the remaining data one page at a time. */
have_read = size;
to_read = le32_to_cpu(rp->system_page_size) - size;
idx = (pos + size) >> PAGE_CACHE_SHIFT;
BUG_ON((pos + size) & ~PAGE_CACHE_MASK);
do {
page = ntfs_map_page(vi->i_mapping, idx);
if (IS_ERR(page)) {
ntfs_error(vi->i_sb, "Error mapping $LogFile "
"page (index %lu).", idx);
goto err_out;
}
size = min_t(int, to_read, PAGE_CACHE_SIZE);
memcpy((u8*)trp + have_read, page_address(page), size);
ntfs_unmap_page(page);
have_read += size;
to_read -= size;
idx++;
} while (to_read > 0);
}
/* Perform the multi sector transfer deprotection on the buffer. */
if (post_read_mst_fixup((NTFS_RECORD*)trp,
le32_to_cpu(rp->system_page_size))) {
ntfs_error(vi->i_sb, "Multi sector transfer error detected in "
"$LogFile restart page.");
goto err_out;
}
/* Check the log client records for consistency. */
ret = ntfs_check_log_client_array(vi, trp);
if (ret && wrp)
*wrp = trp;
else
ntfs_free(trp);
ntfs_debug("Done.");
return ret;
err_out:
ntfs_free(trp);
return FALSE;
}
/**
* ntfs_check_logfile - check the journal for consistency
* @log_vi: struct inode of loaded journal $LogFile to check
*
* Check the $LogFile journal for consistency and return TRUE if it is
* consistent and FALSE if not.
*
* 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(struct inode *log_vi)
{
s64 size, pos, rstr1_pos, rstr2_pos;
ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
struct address_space *mapping = log_vi->i_mapping;
struct page *page = NULL;
u8 *kaddr = NULL;
RESTART_PAGE_HEADER *rstr1_ph = NULL;
RESTART_PAGE_HEADER *rstr2_ph = NULL;
int log_page_size, log_page_mask, ofs;
BOOL logfile_is_empty = TRUE;
BOOL rstr1_found = FALSE;
BOOL rstr2_found = FALSE;
u8 log_page_bits;
ntfs_debug("Entering.");
/* An empty $LogFile must have been clean before it got emptied. */
if (NVolLogFileEmpty(vol))
goto is_empty;
size = i_size_read(log_vi);
/* Make sure the file doesn't exceed the maximum allowed size. */
if (size > MaxLogFileSize)
size = MaxLogFileSize;
/*
* Truncate size to a multiple of the page cache size or the default
* log page size if the page cache size is between the default log page
* log page size if the page cache size is between the default log page
* size and twice that.
*/
if (PAGE_CACHE_SIZE >= DefaultLogPageSize && PAGE_CACHE_SIZE <=
DefaultLogPageSize * 2)
log_page_size = DefaultLogPageSize;
else
log_page_size = PAGE_CACHE_SIZE;
log_page_mask = log_page_size - 1;
/*
* Use generic_ffs() instead of ffs() to enable the compiler to
* optimize log_page_size and log_page_bits into constants.
*/
log_page_bits = generic_ffs(log_page_size) - 1;
size &= ~(s64)(log_page_size - 1);
/*
* Ensure the log file is big enough to store at least the two restart
* pages and the minimum number of log record pages.
*/
if (size < log_page_size * 2 || (size - log_page_size * 2) >>
log_page_bits < MinLogRecordPages) {
ntfs_error(vol->sb, "$LogFile is too small.");
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 uninitialzed records, the log file can be assumed
* to be empty.
*/
for (pos = 0; pos < size; pos <<= 1) {
pgoff_t idx = pos >> PAGE_CACHE_SHIFT;
if (!page || page->index != idx) {
if (page)
ntfs_unmap_page(page);
page = ntfs_map_page(mapping, idx);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Error mapping $LogFile "
"page (index %lu).", idx);
return FALSE;
}
}
kaddr = (u8*)page_address(page) + (pos & ~PAGE_CACHE_MASK);
/*
* A non-empty block means the logfile is not empty while an
* empty block after a non-empty block has been encountered
* means we are done.
*/
if (!ntfs_is_empty_recordp((le32*)kaddr))
logfile_is_empty = FALSE;
else if (!logfile_is_empty)
break;
/*
* A log record page means there cannot be a restart page after
* this so no need to continue searching.
*/
if (ntfs_is_rcrd_recordp((le32*)kaddr))
break;
/*
* A modified by chkdsk restart page means we cannot handle
* this log file.
*/
if (ntfs_is_chkd_recordp((le32*)kaddr)) {
ntfs_error(vol->sb, "$LogFile has been modified by "
"chkdsk. Mount this volume in "
"Windows.");
goto err_out;
}
/* If not a restart page, continue. */
if (!ntfs_is_rstr_recordp((le32*)kaddr)) {
/* Skip to the minimum page size for the next one. */
if (!pos)
pos = NTFS_BLOCK_SIZE >> 1;
continue;
}
/* We now know we have a restart page. */
if (!pos) {
rstr1_found = TRUE;
rstr1_pos = pos;
} else {
if (rstr2_found) {
ntfs_error(vol->sb, "Found more than two "
"restart pages in $LogFile.");
goto err_out;
}
rstr2_found = TRUE;
rstr2_pos = pos;
}
/*
* Check the restart page for consistency and get a copy of the
* complete multi sector transfer deprotected restart page.
*/
if (!ntfs_check_and_load_restart_page(log_vi,
(RESTART_PAGE_HEADER*)kaddr, pos,
!pos ? &rstr1_ph : &rstr2_ph)) {
/* Error output already done inside the function. */
goto err_out;
}
/*
* We have a valid restart page. The next one must be after
* a whole system page size as specified by the valid restart
* page.
*/
if (!pos)
pos = le32_to_cpu(rstr1_ph->system_page_size) >> 1;
}
if (page) {
ntfs_unmap_page(page);
page = NULL;
}
if (logfile_is_empty) {
NVolSetLogFileEmpty(vol);
is_empty:
ntfs_debug("Done. ($LogFile is empty.)");
return TRUE;
}
if (!rstr1_found || !rstr2_found) {
ntfs_error(vol->sb, "Did not find two restart pages in "
"$LogFile.");
goto err_out;
}
/*
* The two restart areas must be identical except for the update
* sequence number.
*/
ofs = le16_to_cpu(rstr1_ph->usa_ofs);
if (memcmp(rstr1_ph, rstr2_ph, ofs) || (ofs += sizeof(u16),
memcmp((u8*)rstr1_ph + ofs, (u8*)rstr2_ph + ofs,
le32_to_cpu(rstr1_ph->system_page_size) - ofs))) {
ntfs_error(vol->sb, "The two restart pages in $LogFile do not "
"match.");
goto err_out;
}
ntfs_free(rstr1_ph);
ntfs_free(rstr2_ph);
/* All consistency checks passed. */
ntfs_debug("Done.");
return TRUE;
err_out:
if (page)
ntfs_unmap_page(page);
if (rstr1_ph)
ntfs_free(rstr1_ph);
if (rstr2_ph)
ntfs_free(rstr2_ph);
return FALSE;
}
/**
* ntfs_is_logfile_clean - check in the journal if the volume is clean
* @log_vi: struct inode of loaded journal $LogFile to check
*
* 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 preceeding 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(struct inode *log_vi)
{
ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
struct page *page;
RESTART_PAGE_HEADER *rp;
RESTART_AREA *ra;
ntfs_debug("Entering.");
/* An empty $LogFile must have been clean before it got emptied. */
if (NVolLogFileEmpty(vol)) {
ntfs_debug("Done. ($LogFile is empty.)");
return TRUE;
}
/*
* Read the first restart page. It will be possibly incomplete and
* will not be multi sector transfer deprotected but we only need the
* first NTFS_BLOCK_SIZE bytes so it does not matter.
*/
page = ntfs_map_page(log_vi->i_mapping, 0);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Error mapping $LogFile page (index 0).");
return FALSE;
}
rp = (RESTART_PAGE_HEADER*)page_address(page);
if (!ntfs_is_rstr_record(rp->magic)) {
ntfs_error(vol->sb, "No restart page found at offset zero in "
"$LogFile. This is probably a bug in that "
"the $LogFile should have been consistency "
"checked before calling this function.");
goto err_out;
}
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_debug("Done. $LogFile indicates a dirty shutdown.");
goto err_out;
}
ntfs_unmap_page(page);
/* $LogFile indicates a clean shutdown. */
ntfs_debug("Done. $LogFile indicates a clean shutdown.");
return TRUE;
err_out:
ntfs_unmap_page(page);
return FALSE;
}
/**
* ntfs_empty_logfile - empty the contents of the $LogFile journal
* @log_vi: struct inode of loaded journal $LogFile to empty
*
* Empty the contents of the $LogFile journal @log_vi and return TRUE on
* success and FALSE 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.
*/
BOOL ntfs_empty_logfile(struct inode *log_vi)
{
ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
ntfs_debug("Entering.");
if (!NVolLogFileEmpty(vol)) {
int err;
err = ntfs_attr_set(NTFS_I(log_vi), 0, i_size_read(log_vi),
0xff);
if (unlikely(err)) {
ntfs_error(vol->sb, "Failed to fill $LogFile with "
"0xff bytes (error code %i).", err);
return FALSE;
}
/* Set the flag so we do not have to do it again on remount. */
NVolSetLogFileEmpty(vol);
}
ntfs_debug("Done.");
return TRUE;
}
#endif /* NTFS_RW */
