/* * 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 #include #include #include #include #include #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 */