148 files changed, 141286 insertions, 0 deletions
diff --git a/libntfs-3g/bitmap.c b/libntfs-3g/bitmap.c new file mode 100755 index 0000000..65162a2 --- a/dev/null +++ b/libntfs-3g/bitmap.c @@ -0,0 +1,300 @@ +/** + * bitmap.c - Bitmap handling code. Originated from the Linux-NTFS project. + * + * Copyright (c) 2002-2006 Anton Altaparmakov + * Copyright (c) 2004-2005 Richard Russon + * Copyright (c) 2004-2008 Szabolcs Szakacsits + * + * 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 NTFS-3G + * 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 HAVE_CONFIG_H +#include "config.h" +#endif + +#ifdef HAVE_STDLIB_H +#include <stdlib.h> +#endif +#ifdef HAVE_STDIO_H +#include <stdio.h> +#endif +#ifdef HAVE_STRING_H +#include <string.h> +#endif +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif + +#include "types.h" +#include "attrib.h" +#include "bitmap.h" +#include "debug.h" +#include "logging.h" +#include "misc.h" + +/** + * ntfs_bit_set - set a bit in a field of bits + * @bitmap: field of bits + * @bit: bit to set + * @new_value: value to set bit to (0 or 1) + * + * Set the bit @bit in the @bitmap to @new_value. Ignore all errors. + */ +void ntfs_bit_set(u8 *bitmap, const u64 bit, const u8 new_value) +{ + if (!bitmap || new_value > 1) + return; + if (!new_value) + bitmap[bit >> 3] &= ~(1 << (bit & 7)); + else + bitmap[bit >> 3] |= (1 << (bit & 7)); +} + +/** + * ntfs_bit_get - get value of a bit in a field of bits + * @bitmap: field of bits + * @bit: bit to get + * + * Get and return the value of the bit @bit in @bitmap (0 or 1). + * Return -1 on error. + */ +char ntfs_bit_get(const u8 *bitmap, const u64 bit) +{ + if (!bitmap) + return -1; + return (bitmap[bit >> 3] >> (bit & 7)) & 1; +} + +/** + * ntfs_bit_get_and_set - get value of a bit in a field of bits and set it + * @bitmap: field of bits + * @bit: bit to get/set + * @new_value: value to set bit to (0 or 1) + * + * Return the value of the bit @bit and set it to @new_value (0 or 1). + * Return -1 on error. + */ +char ntfs_bit_get_and_set(u8 *bitmap, const u64 bit, const u8 new_value) +{ + register u8 old_bit, shift; + + if (!bitmap || new_value > 1) + return -1; + shift = bit & 7; + old_bit = (bitmap[bit >> 3] >> shift) & 1; + if (new_value != old_bit) + bitmap[bit >> 3] ^= 1 << shift; + return old_bit; +} + +/** + * ntfs_bitmap_set_bits_in_run - set a run of bits in a bitmap to a value + * @na: attribute containing the bitmap + * @start_bit: first bit to set + * @count: number of bits to set + * @value: value to set the bits to (i.e. 0 or 1) + * + * Set @count bits starting at bit @start_bit in the bitmap described by the + * attribute @na to @value, where @value is either 0 or 1. + * + * On success return 0 and on error return -1 with errno set to the error code. + */ +static int ntfs_bitmap_set_bits_in_run(ntfs_attr *na, s64 start_bit, + s64 count, int value) +{ + s64 bufsize, br; + u8 *buf, *lastbyte_buf; + int bit, firstbyte, lastbyte, lastbyte_pos, tmp, ret = -1; + + if (!na || start_bit < 0 || count < 0) { + errno = EINVAL; + ntfs_log_perror("%s: Invalid argument (%p, %lld, %lld)", + __FUNCTION__, na, (long long)start_bit, (long long)count); + return -1; + } + + bit = start_bit & 7; + if (bit) + firstbyte = 1; + else + firstbyte = 0; + + /* Calculate the required buffer size in bytes, capping it at 8kiB. */ + bufsize = ((count - (bit ? 8 - bit : 0) + 7) >> 3) + firstbyte; + if (bufsize > 8192) + bufsize = 8192; + + buf = ntfs_malloc(bufsize); + if (!buf) + return -1; + + /* Depending on @value, zero or set all bits in the allocated buffer. */ + memset(buf, value ? 0xff : 0, bufsize); + + /* If there is a first partial byte... */ + if (bit) { + /* read it in... */ + br = ntfs_attr_pread(na, start_bit >> 3, 1, buf); + if (br != 1) { + if (br >= 0) + errno = EIO; + goto free_err_out; + } + /* and set or clear the appropriate bits in it. */ + while ((bit & 7) && count--) { + if (value) + *buf |= 1 << bit++; + else + *buf &= ~(1 << bit++); + } + /* Update @start_bit to the new position. */ + start_bit = (start_bit + 7) & ~7; + } + + /* Loop until @count reaches zero. */ + lastbyte = 0; + lastbyte_buf = NULL; + bit = count & 7; + do { + /* If there is a last partial byte... */ + if (count > 0 && bit) { + lastbyte_pos = ((count + 7) >> 3) + firstbyte; + if (!lastbyte_pos) { + // FIXME: Eeek! BUG! + ntfs_log_error("Lastbyte is zero. Leaving " + "inconsistent metadata.\n"); + errno = EIO; + goto free_err_out; + } + /* and it is in the currently loaded bitmap window... */ + if (lastbyte_pos <= bufsize) { + lastbyte_buf = buf + lastbyte_pos - 1; + + /* read the byte in... */ + br = ntfs_attr_pread(na, (start_bit + count) >> + 3, 1, lastbyte_buf); + if (br != 1) { + // FIXME: Eeek! We need rollback! (AIA) + if (br >= 0) + errno = EIO; + ntfs_log_perror("Reading of last byte " + "failed (%lld). Leaving inconsistent " + "metadata", (long long)br); + goto free_err_out; + } + /* and set/clear the appropriate bits in it. */ + while (bit && count--) { + if (value) + *lastbyte_buf |= 1 << --bit; + else + *lastbyte_buf &= ~(1 << --bit); + } + /* We don't want to come back here... */ + bit = 0; + /* We have a last byte that we have handled. */ + lastbyte = 1; + } + } + + /* Write the prepared buffer to disk. */ + tmp = (start_bit >> 3) - firstbyte; + br = ntfs_attr_pwrite(na, tmp, bufsize, buf); + if (br != bufsize) { + // FIXME: Eeek! We need rollback! (AIA) + if (br >= 0) + errno = EIO; + ntfs_log_perror("Failed to write buffer to bitmap " + "(%lld != %lld). Leaving inconsistent metadata", + (long long)br, (long long)bufsize); + goto free_err_out; + } + + /* Update counters. */ + tmp = (bufsize - firstbyte - lastbyte) << 3; + if (firstbyte) { + firstbyte = 0; + /* + * Re-set the partial first byte so a subsequent write + * of the buffer does not have stale, incorrect bits. + */ + *buf = value ? 0xff : 0; + } + start_bit += tmp; + count -= tmp; + if (bufsize > (tmp = (count + 7) >> 3)) + bufsize = tmp; + + if (lastbyte && count != 0) { + // FIXME: Eeek! BUG! + ntfs_log_error("Last buffer but count is not zero " + "(%lld). Leaving inconsistent metadata.\n", + (long long)count); + errno = EIO; + goto free_err_out; + } + } while (count > 0); + + ret = 0; + +free_err_out: + free(buf); + return ret; +} + +/** + * ntfs_bitmap_set_run - set a run of bits in a bitmap + * @na: attribute containing the bitmap + * @start_bit: first bit to set + * @count: number of bits to set + * + * Set @count bits starting at bit @start_bit in the bitmap described by the + * attribute @na. + * + * On success return 0 and on error return -1 with errno set to the error code. + */ +int ntfs_bitmap_set_run(ntfs_attr *na, s64 start_bit, s64 count) +{ + int ret; + + ntfs_log_enter("Set from bit %lld, count %lld\n", + (long long)start_bit, (long long)count); + ret = ntfs_bitmap_set_bits_in_run(na, start_bit, count, 1); + ntfs_log_leave("\n"); + return ret; +} + +/** + * ntfs_bitmap_clear_run - clear a run of bits in a bitmap + * @na: attribute containing the bitmap + * @start_bit: first bit to clear + * @count: number of bits to clear + * + * Clear @count bits starting at bit @start_bit in the bitmap described by the + * attribute @na. + * + * On success return 0 and on error return -1 with errno set to the error code. + */ +int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count) +{ + int ret; + + ntfs_log_enter("Clear from bit %lld, count %lld\n", + (long long)start_bit, (long long)count); + ret = ntfs_bitmap_set_bits_in_run(na, start_bit, count, 0); + ntfs_log_leave("\n"); + return ret; +} + |