- 根目录:
- fs
- ntfs
- logfile.c
/*
* logfile.c - NTFS kernel journal handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2002-2007 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 <linux/log2.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: $LogFile inode to which the restart page header belongs
* @rp: restart page header to check
* @pos: position in @vi at which the restart page header resides
*
* Check the restart page header @rp for consistency and return 'true' if it is
* consistent and 'false' otherwise.
*
* This function only needs NTFS_BLOCK_SIZE bytes in @rp, i.e. it does not
* require the full restart page.
*/
static bool ntfs_check_restart_page_header(struct inode *vi,
RESTART_PAGE_HEADER *rp, s64 pos)
{
u32 logfile_system_page_size, logfile_log_page_size;
u16 ra_ofs, usa_count, usa_ofs, usa_end = 0;
bool have_usa = true;
ntfs_debug("Entering.");
/*
* If the system or log page sizes are smaller than the ntfs block size
* or either is not a power of 2 we cannot handle this log file.
*/
logfile_system_page_size = le32_to_cpu(rp->system_page_size);
logfile_log_page_size = le32_to_cpu(rp->log_page_size);
if (logfile_system_page_size < NTFS_BLOCK_SIZE ||
logfile_log_page_size < NTFS_BLOCK_SIZE ||
logfile_system_page_size &
(logfile_system_page_size - 1) ||
!is_power_of_2(logfile_log_page_size)) {
ntfs_error(vi->i_sb, "$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 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(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 $LogFile must have been clean before it got emptied. */
if (NVolLogFileEmpty(vol))
goto is_empty;
size = i_size_read(log_vi);
/* Make sure the file doesn't exceed the maximum allowed size. */
if (size > MaxLogFileSize)
size = MaxLogFileSize;
/*
* Truncate size to a multiple of the page cache size or the default
* log page size if the page cache size is between the default log page
* log page size if the page cache size is between the default log page
* size and twice that.
*/
if (PAGE_CACHE_SIZE >= DefaultLogPageSize && PAGE_CACHE_SIZE <=
DefaultLogPageSize * 2)
log_page_size = DefaultLogPageSize;
else
log_page_size = PAGE_CACHE_SIZE;
log_page_mask = log_page_size - 1;
/*
* Use ntfs_ffs() instead of ffs() to enable the compiler to
* optimize log_page_size and log_page_bits into constants.
*/
log_page_bits = ntfs_ffs(log_page_size) - 1;
size &= ~(s64)(log_page_size - 1);
/*
* Ensure the log file is big enough to store at least the two restart
* pages and the minimum number of log record pages.
*/
if (size < log_page_size * 2 || (size - log_page_size * 2) >>
log_page_bits < MinLogRecordPages) {
ntfs_error(vol->sb, "$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 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(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)
{
VCN vcn, end_vcn;
ntfs_inode *log_ni = NTFS_I(log_vi);
ntfs_volume *vol = log_ni->vol;
struct super_block *sb = vol->sb;
runlist_element *rl;
unsigned long flags;
unsigned block_size, block_size_bits;
int err;
bool should_wait = true;
ntfs_debug("Entering.");
if (NVolLogFileEmpty(vol)) {
ntfs_debug("Done.");
return true;
}
/*
* We cannot use ntfs_attr_set() because we may be still in the middle
* of a mount operation. Thus we do the emptying by hand by first
* zapping the page cache pages for the $LogFile/$DATA attribute and
* then emptying each of the buffers in each of the clusters specified
* by the runlist by hand.
*/
block_size = sb->s_blocksize;
block_size_bits = sb->s_blocksize_bits;
vcn = 0;
read_lock_irqsave(&log_ni->size_lock, flags);
end_vcn = (log_ni->initialized_size + vol->cluster_size_mask) >>
vol->cluster_size_bits;
read_unlock_irqrestore(&log_ni->size_lock, flags);
truncate_inode_pages(log_vi->i_mapping, 0);
down_write(&log_ni->runlist.lock);
rl = log_ni->runlist.rl;
if (unlikely(!rl || vcn < rl->vcn || !rl->length)) {
map_vcn:
err = ntfs_map_runlist_nolock(log_ni, vcn, NULL);
if (err) {
ntfs_error(sb, "Failed to map runlist fragment (error "
"%d).", -err);
goto err;
}
rl = log_ni->runlist.rl;
BUG_ON(!rl || vcn < rl->vcn || !rl->length);
}
/* Seek to the runlist element containing @vcn. */
while (rl->length && vcn >= rl[1].vcn)
rl++;
do {
LCN lcn;
sector_t block, end_block;
s64 len;
/*
* If this run is not mapped map it now and start again as the
* runlist will have been updated.
*/
lcn = rl->lcn;
if (unlikely(lcn == LCN_RL_NOT_MAPPED)) {
vcn = rl->vcn;
goto map_vcn;
}
/* If this run is not valid abort with an error. */
if (unlikely(!rl->length || lcn < LCN_HOLE))
goto rl_err;
/* Skip holes. */
if (lcn == LCN_HOLE)
continue;
block = lcn << vol->cluster_size_bits >> block_size_bits;
len = rl->length;
if (rl[1].vcn > end_vcn)
len = end_vcn - rl->vcn;
end_block = (lcn + len) << vol->cluster_size_bits >>
block_size_bits;
/* Iterate over the blocks in the run and empty them. */
do {
struct buffer_head *bh;
/* Obtain the buffer, possibly not uptodate. */
bh = sb_getblk(sb, block);
BUG_ON(!bh);
/* Setup buffer i/o submission. */
lock_buffer(bh);
bh->b_end_io = end_buffer_write_sync;
get_bh(bh);
/* Set the entire contents of the buffer to 0xff. */
memset(bh->b_data, -1, block_size);
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
if (buffer_dirty(bh))
clear_buffer_dirty(bh);
/*
* Submit the buffer and wait for i/o to complete but
* only for the first buffer so we do not miss really
* serious i/o errors. Once the first buffer has
* completed ignore errors afterwards as we can assume
* that if one buffer worked all of them will work.
*/
submit_bh(WRITE, bh);
if (should_wait) {
should_wait = false;
wait_on_buffer(bh);
if (unlikely(!buffer_uptodate(bh)))
goto io_err;
}
brelse(bh);
} while (++block < end_block);
} while ((++rl)->vcn < end_vcn);
up_write(&log_ni->runlist.lock);
/*
* Zap the pages again just in case any got instantiated whilst we were
* emptying the blocks by hand. FIXME: We may not have completed
* writing to all the buffer heads yet so this may happen too early.
* We really should use a kernel thread to do the emptying
* asynchronously and then we can also set the volume dirty and output
* an error message if emptying should fail.
*/
truncate_inode_pages(log_vi->i_mapping, 0);
/* Set the flag so we do not have to do it again on remount. */
NVolSetLogFileEmpty(vol);
ntfs_debug("Done.");
return true;
io_err:
ntfs_error(sb, "Failed to write buffer. Unmount and run chkdsk.");
goto dirty_err;
rl_err:
ntfs_error(sb, "Runlist is corrupt. Unmount and run chkdsk.");
dirty_err:
NVolSetErrors(vol);
err = -EIO;
err:
up_write(&log_ni->runlist.lock);
ntfs_error(sb, "Failed to fill $LogFile with 0xff bytes (error %d).",
-err);
return false;
}
#endif /* NTFS_RW */