diff options
Diffstat (limited to 'e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c')
| -rw-r--r-- | e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c b/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c new file mode 100644 index 0000000..a5782db --- /dev/null +++ b/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c @@ -0,0 +1,296 @@ +/* vi: set sw=4 ts=4: */ +/* + * rw_bitmaps.c --- routines to read and write the inode and block bitmaps. + * + * Copyright (C) 1993, 1994, 1994, 1996 Theodore Ts'o. + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Public + * License. + * %End-Header% + */ + +#include <stdio.h> +#include <string.h> +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#include <fcntl.h> +#include <time.h> +#ifdef HAVE_SYS_STAT_H +#include <sys/stat.h> +#endif +#ifdef HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#include "ext2_fs.h" +#include "ext2fs.h" +#include "e2image.h" + +#if defined(__powerpc__) && BB_BIG_ENDIAN +/* + * On the PowerPC, the big-endian variant of the ext2 filesystem + * has its bitmaps stored as 32-bit words with bit 0 as the LSB + * of each word. Thus a bitmap with only bit 0 set would be, as + * a string of bytes, 00 00 00 01 00 ... + * To cope with this, we byte-reverse each word of a bitmap if + * we have a big-endian filesystem, that is, if we are *not* + * byte-swapping other word-sized numbers. + */ +#define EXT2_BIG_ENDIAN_BITMAPS +#endif + +#ifdef EXT2_BIG_ENDIAN_BITMAPS +static void ext2fs_swap_bitmap(ext2_filsys fs, char *bitmap, int nbytes) +{ + __u32 *p = (__u32 *) bitmap; + int n; + + for (n = nbytes / sizeof(__u32); n > 0; --n, ++p) + *p = ext2fs_swab32(*p); +} +#endif + +errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs) +{ + dgrp_t i; + size_t nbytes; + errcode_t retval; + char * inode_bitmap = fs->inode_map->bitmap; + char * bitmap_block = NULL; + blk_t blk; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (!(fs->flags & EXT2_FLAG_RW)) + return EXT2_ET_RO_FILSYS; + if (!inode_bitmap) + return 0; + nbytes = (size_t) ((EXT2_INODES_PER_GROUP(fs->super)+7) / 8); + + retval = ext2fs_get_mem(fs->blocksize, &bitmap_block); + if (retval) + return retval; + memset(bitmap_block, 0xff, fs->blocksize); + for (i = 0; i < fs->group_desc_count; i++) { + memcpy(bitmap_block, inode_bitmap, nbytes); + blk = fs->group_desc[i].bg_inode_bitmap; + if (blk) { +#ifdef EXT2_BIG_ENDIAN_BITMAPS + if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) || + (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))) + ext2fs_swap_bitmap(fs, bitmap_block, nbytes); +#endif + retval = io_channel_write_blk(fs->io, blk, 1, + bitmap_block); + if (retval) + return EXT2_ET_INODE_BITMAP_WRITE; + } + inode_bitmap += nbytes; + } + fs->flags &= ~EXT2_FLAG_IB_DIRTY; + ext2fs_free_mem(&bitmap_block); + return 0; +} + +errcode_t ext2fs_write_block_bitmap (ext2_filsys fs) +{ + dgrp_t i; + unsigned int j; + int nbytes; + unsigned int nbits; + errcode_t retval; + char * block_bitmap = fs->block_map->bitmap; + char * bitmap_block = NULL; + blk_t blk; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (!(fs->flags & EXT2_FLAG_RW)) + return EXT2_ET_RO_FILSYS; + if (!block_bitmap) + return 0; + nbytes = EXT2_BLOCKS_PER_GROUP(fs->super) / 8; + retval = ext2fs_get_mem(fs->blocksize, &bitmap_block); + if (retval) + return retval; + memset(bitmap_block, 0xff, fs->blocksize); + for (i = 0; i < fs->group_desc_count; i++) { + memcpy(bitmap_block, block_bitmap, nbytes); + if (i == fs->group_desc_count - 1) { + /* Force bitmap padding for the last group */ + nbits = ((fs->super->s_blocks_count + - fs->super->s_first_data_block) + % EXT2_BLOCKS_PER_GROUP(fs->super)); + if (nbits) + for (j = nbits; j < fs->blocksize * 8; j++) + ext2fs_set_bit(j, bitmap_block); + } + blk = fs->group_desc[i].bg_block_bitmap; + if (blk) { +#ifdef EXT2_BIG_ENDIAN_BITMAPS + if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) || + (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))) + ext2fs_swap_bitmap(fs, bitmap_block, nbytes); +#endif + retval = io_channel_write_blk(fs->io, blk, 1, + bitmap_block); + if (retval) + return EXT2_ET_BLOCK_BITMAP_WRITE; + } + block_bitmap += nbytes; + } + fs->flags &= ~EXT2_FLAG_BB_DIRTY; + ext2fs_free_mem(&bitmap_block); + return 0; +} + +static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block) +{ + dgrp_t i; + char *block_bitmap = 0, *inode_bitmap = 0; + char *buf; + errcode_t retval; + int block_nbytes = (int) EXT2_BLOCKS_PER_GROUP(fs->super) / 8; + int inode_nbytes = (int) EXT2_INODES_PER_GROUP(fs->super) / 8; + blk_t blk; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + fs->write_bitmaps = ext2fs_write_bitmaps; + + retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); + if (retval) + return retval; + if (do_block) { + ext2fs_free_block_bitmap(fs->block_map); + sprintf(buf, "block bitmap for %s", fs->device_name); + retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map); + if (retval) + goto cleanup; + block_bitmap = fs->block_map->bitmap; + } + if (do_inode) { + ext2fs_free_inode_bitmap(fs->inode_map); + sprintf(buf, "inode bitmap for %s", fs->device_name); + retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); + if (retval) + goto cleanup; + inode_bitmap = fs->inode_map->bitmap; + } + ext2fs_free_mem(&buf); + + if (fs->flags & EXT2_FLAG_IMAGE_FILE) { + if (inode_bitmap) { + blk = (fs->image_header->offset_inodemap / + fs->blocksize); + retval = io_channel_read_blk(fs->image_io, blk, + -(inode_nbytes * fs->group_desc_count), + inode_bitmap); + if (retval) + goto cleanup; + } + if (block_bitmap) { + blk = (fs->image_header->offset_blockmap / + fs->blocksize); + retval = io_channel_read_blk(fs->image_io, blk, + -(block_nbytes * fs->group_desc_count), + block_bitmap); + if (retval) + goto cleanup; + } + return 0; + } + + for (i = 0; i < fs->group_desc_count; i++) { + if (block_bitmap) { + blk = fs->group_desc[i].bg_block_bitmap; + if (blk) { + retval = io_channel_read_blk(fs->io, blk, + -block_nbytes, block_bitmap); + if (retval) { + retval = EXT2_ET_BLOCK_BITMAP_READ; + goto cleanup; + } +#ifdef EXT2_BIG_ENDIAN_BITMAPS + if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) || + (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))) + ext2fs_swap_bitmap(fs, block_bitmap, block_nbytes); +#endif + } else + memset(block_bitmap, 0, block_nbytes); + block_bitmap += block_nbytes; + } + if (inode_bitmap) { + blk = fs->group_desc[i].bg_inode_bitmap; + if (blk) { + retval = io_channel_read_blk(fs->io, blk, + -inode_nbytes, inode_bitmap); + if (retval) { + retval = EXT2_ET_INODE_BITMAP_READ; + goto cleanup; + } +#ifdef EXT2_BIG_ENDIAN_BITMAPS + if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) || + (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))) + ext2fs_swap_bitmap(fs, inode_bitmap, inode_nbytes); +#endif + } else + memset(inode_bitmap, 0, inode_nbytes); + inode_bitmap += inode_nbytes; + } + } + return 0; + +cleanup: + if (do_block) { + ext2fs_free_mem(&fs->block_map); + } + if (do_inode) { + ext2fs_free_mem(&fs->inode_map); + } + ext2fs_free_mem(&buf); + return retval; +} + +errcode_t ext2fs_read_inode_bitmap (ext2_filsys fs) +{ + return read_bitmaps(fs, 1, 0); +} + +errcode_t ext2fs_read_block_bitmap(ext2_filsys fs) +{ + return read_bitmaps(fs, 0, 1); +} + +errcode_t ext2fs_read_bitmaps(ext2_filsys fs) +{ + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (fs->inode_map && fs->block_map) + return 0; + + return read_bitmaps(fs, !fs->inode_map, !fs->block_map); +} + +errcode_t ext2fs_write_bitmaps(ext2_filsys fs) +{ + errcode_t retval; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (fs->block_map && ext2fs_test_bb_dirty(fs)) { + retval = ext2fs_write_block_bitmap(fs); + if (retval) + return retval; + } + if (fs->inode_map && ext2fs_test_ib_dirty(fs)) { + retval = ext2fs_write_inode_bitmap(fs); + if (retval) + return retval; + } + return 0; +} + |