--- /dev/null
+/*
+ * 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 */
Code Review / kvmfornfv.git / blobdiff