linux/fs/ntfs/logfile.c
Anton Altaparmakov 5a8c0cc32b NTFS: More $LogFile handling fixes: when chkdsk has been run, it can leave the
restart pages in the journal without multi sector transfer protection
      fixups (i.e. the update sequence array is empty and in fact does not
      exist).

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-09-26 10:48:54 +01:00

748 lines
25 KiB
C

/*
* 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: $LogFile inode to which the restart page header belongs
* @rp: restart page header to check
* @pos: position in @vi at which the restart page header resides
*
* Check the restart page header @rp for consistency and return TRUE if it is
* consistent and FALSE otherwise.
*
* This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
* require the full restart page.
*/
static BOOL ntfs_check_restart_page_header(struct inode *vi,
RESTART_PAGE_HEADER *rp, s64 pos)
{
u32 logfile_system_page_size, logfile_log_page_size;
u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
BOOL have_usa = TRUE;
ntfs_debug("Entering.");
/*
* If the system or log page sizes are smaller than the ntfs block size
* or either is not a power of 2 we cannot handle this log file.
*/
logfile_system_page_size = le32_to_cpu(rp->system_page_size);
logfile_log_page_size = le32_to_cpu(rp->log_page_size);
if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
logfile_log_page_size < NTFS_BLOCK_SIZE ||
logfile_system_page_size &
(logfile_system_page_size - 1) ||
logfile_log_page_size & (logfile_log_page_size - 1)) {
ntfs_error(vi->i_sb, "$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;
}
/*
* 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_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;
}
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_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 "
"by 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: [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.
*
* Simillarly, if @lsn is not NULL, on succes *@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(struct inode *vi,
RESTART_PAGE_HEADER *rp, s64 pos, RESTART_PAGE_HEADER **wrp,
LSN *lsn)
{
RESTART_AREA *ra;
RESTART_PAGE_HEADER *trp;
int size, err;
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 -EINVAL;
}
/* Check the restart area for consistency. */
if (!ntfs_check_restart_area(vi, 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_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 -ENOMEM;
}
/*
* 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);
err = PTR_ERR(page);
if (err != -EIO && err != -ENOMEM)
err = -EIO;
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 the
* restart page is protected.
*/
if ((!ntfs_is_chkd_record(trp->magic) || le16_to_cpu(trp->usa_count))
&& post_read_mst_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 - sizeof(u16)) {
ntfs_error(vi->i_sb, "Multi sector transfer error "
"detected in $LogFile restart page.");
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(vi, 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_debug("Done.");
if (wrp)
*wrp = trp;
else {
err_out:
ntfs_free(trp);
}
return err;
}
/**
* ntfs_check_logfile - check the journal for consistency
* @log_vi: struct inode 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(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
{
s64 size, pos;
LSN rstr1_lsn, rstr2_lsn;
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, err;
BOOL logfile_is_empty = TRUE;
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 $LogFile "
"page (index %lu).", idx);
goto err_out;
}
}
kaddr = (u8*)page_address(page) + (pos & ~PAGE_CACHE_MASK);
/*
* A non-empty block means the logfile is not empty while an
* empty block after a non-empty block has been encountered
* means we are done.
*/
if (!ntfs_is_empty_recordp((le32*)kaddr))
logfile_is_empty = FALSE;
else if (!logfile_is_empty)
break;
/*
* A log record page means there cannot be a restart page after
* this so no need to continue searching.
*/
if (ntfs_is_rcrd_recordp((le32*)kaddr))
break;
/* If not a (modified by chkdsk) restart page, continue. */
if (!ntfs_is_rstr_recordp((le32*)kaddr) &&
!ntfs_is_chkd_recordp((le32*)kaddr)) {
if (!pos)
pos = NTFS_BLOCK_SIZE >> 1;
continue;
}
/*
* Check the (modified by chkdsk) restart page for consistency
* and get a copy of the complete multi sector transfer
* deprotected restart page.
*/
err = ntfs_check_and_load_restart_page(log_vi,
(RESTART_PAGE_HEADER*)kaddr, pos,
!rstr1_ph ? &rstr1_ph : &rstr2_ph,
!rstr1_ph ? &rstr1_lsn : &rstr2_lsn);
if (!err) {
/*
* If we have now found the first (modified by chkdsk)
* restart page, continue looking for the second one.
*/
if (!pos) {
pos = NTFS_BLOCK_SIZE >> 1;
continue;
}
/*
* We have now found the second (modified by chkdsk)
* restart page, so we can stop looking.
*/
break;
}
/*
* Error output already done inside the function. Note, we do
* not abort if the restart page was invalid as we might still
* find a valid one further in the file.
*/
if (err != -EINVAL) {
ntfs_unmap_page(page);
goto err_out;
}
/* Continue looking. */
if (!pos)
pos = NTFS_BLOCK_SIZE >> 1;
}
if (page)
ntfs_unmap_page(page);
if (logfile_is_empty) {
NVolSetLogFileEmpty(vol);
is_empty:
ntfs_debug("Done. ($LogFile is empty.)");
return TRUE;
}
if (!rstr1_ph) {
BUG_ON(rstr2_ph);
ntfs_error(vol->sb, "Did not find any restart pages in "
"$LogFile and it was not empty.");
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_debug("Using second restart page as it is more "
"recent.");
ntfs_free(rstr1_ph);
rstr1_ph = rstr2_ph;
/* rstr1_lsn = rstr2_lsn; */
} else {
ntfs_debug("Using first restart page as it is more "
"recent.");
ntfs_free(rstr2_ph);
}
rstr2_ph = NULL;
}
/* All consistency checks passed. */
if (rp)
*rp = rstr1_ph;
else
ntfs_free(rstr1_ph);
ntfs_debug("Done.");
return TRUE;
err_out:
if (rstr1_ph)
ntfs_free(rstr1_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
* @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 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, const RESTART_PAGE_HEADER *rp)
{
ntfs_volume *vol = NTFS_SB(log_vi->i_sb);
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;
}
BUG_ON(!rp);
if (!ntfs_is_rstr_record(rp->magic) &&
!ntfs_is_chkd_record(rp->magic)) {
ntfs_error(vol->sb, "Restart page buffer is invalid. This is "
"probably a bug in that the $LogFile should "
"have been consistency checked before calling "
"this function.");
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_debug("Done. $LogFile indicates a dirty shutdown.");
return FALSE;
}
/* $LogFile indicates a clean shutdown. */
ntfs_debug("Done. $LogFile indicates a clean shutdown.");
return TRUE;
}
/**
* 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 */