diff options
Diffstat (limited to 'fs/ntfs/logfile.c')
| -rw-r--r-- | fs/ntfs/logfile.c | 863 |
1 files changed, 863 insertions, 0 deletions
diff --git a/fs/ntfs/logfile.c b/fs/ntfs/logfile.c new file mode 100644 index 000000000..c71de292c --- /dev/null +++ b/fs/ntfs/logfile.c @@ -0,0 +1,863 @@ +/* + * 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 */ |