diff options
Diffstat (limited to 'e2fsprogs/old_e2fsprogs/ext2fs/openfs.c')
| -rw-r--r-- | e2fsprogs/old_e2fsprogs/ext2fs/openfs.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/openfs.c b/e2fsprogs/old_e2fsprogs/ext2fs/openfs.c new file mode 100644 index 0000000..716be06 --- /dev/null +++ b/e2fsprogs/old_e2fsprogs/ext2fs/openfs.c @@ -0,0 +1,330 @@ +/* vi: set sw=4 ts=4: */ +/* + * openfs.c --- open an ext2 filesystem + * + * Copyright (C) 1993, 1994, 1995, 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> +#if HAVE_SYS_STAT_H +#include <sys/stat.h> +#endif +#if HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#include "ext2_fs.h" + + +#include "ext2fs.h" +#include "e2image.h" + +blk_t ext2fs_descriptor_block_loc(ext2_filsys fs, blk_t group_block, dgrp_t i) +{ + int bg; + int has_super = 0; + int ret_blk; + + if (!(fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) || + (i < fs->super->s_first_meta_bg)) + return (group_block + i + 1); + + bg = (fs->blocksize / sizeof (struct ext2_group_desc)) * i; + if (ext2fs_bg_has_super(fs, bg)) + has_super = 1; + ret_blk = (fs->super->s_first_data_block + has_super + + (bg * fs->super->s_blocks_per_group)); + /* + * If group_block is not the normal value, we're trying to use + * the backup group descriptors and superblock --- so use the + * alternate location of the second block group in the + * metablock group. Ideally we should be testing each bg + * descriptor block individually for correctness, but we don't + * have the infrastructure in place to do that. + */ + if (group_block != fs->super->s_first_data_block && + ((ret_blk + fs->super->s_blocks_per_group) < + fs->super->s_blocks_count)) + ret_blk += fs->super->s_blocks_per_group; + return ret_blk; +} + +errcode_t ext2fs_open(const char *name, int flags, int superblock, + unsigned int block_size, io_manager manager, + ext2_filsys *ret_fs) +{ + return ext2fs_open2(name, 0, flags, superblock, block_size, + manager, ret_fs); +} + +/* + * Note: if superblock is non-zero, block-size must also be non-zero. + * Superblock and block_size can be zero to use the default size. + * + * Valid flags for ext2fs_open() + * + * EXT2_FLAG_RW - Open the filesystem for read/write. + * EXT2_FLAG_FORCE - Open the filesystem even if some of the + * features aren't supported. + * EXT2_FLAG_JOURNAL_DEV_OK - Open an ext3 journal device + */ +errcode_t ext2fs_open2(const char *name, const char *io_options, + int flags, int superblock, + unsigned int block_size, io_manager manager, + ext2_filsys *ret_fs) +{ + ext2_filsys fs; + errcode_t retval; + unsigned long i; + int groups_per_block, blocks_per_group; + blk_t group_block, blk; + char *dest, *cp; +#if BB_BIG_ENDIAN + int j; + struct ext2_group_desc *gdp; +#endif + + EXT2_CHECK_MAGIC(manager, EXT2_ET_MAGIC_IO_MANAGER); + + retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); + if (retval) + return retval; + + memset(fs, 0, sizeof(struct struct_ext2_filsys)); + fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; + fs->flags = flags; + fs->umask = 022; + retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); + if (retval) + goto cleanup; + strcpy(fs->device_name, name); + cp = strchr(fs->device_name, '?'); + if (!io_options && cp) { + *cp++ = 0; + io_options = cp; + } + + retval = manager->open(fs->device_name, + (flags & EXT2_FLAG_RW) ? IO_FLAG_RW : 0, + &fs->io); + if (retval) + goto cleanup; + if (io_options && + (retval = io_channel_set_options(fs->io, io_options))) + goto cleanup; + fs->image_io = fs->io; + fs->io->app_data = fs; + retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &fs->super); + if (retval) + goto cleanup; + if (flags & EXT2_FLAG_IMAGE_FILE) { + retval = ext2fs_get_mem(sizeof(struct ext2_image_hdr), + &fs->image_header); + if (retval) + goto cleanup; + retval = io_channel_read_blk(fs->io, 0, + -(int)sizeof(struct ext2_image_hdr), + fs->image_header); + if (retval) + goto cleanup; + if (fs->image_header->magic_number != EXT2_ET_MAGIC_E2IMAGE) + return EXT2_ET_MAGIC_E2IMAGE; + superblock = 1; + block_size = fs->image_header->fs_blocksize; + } + + /* + * If the user specifies a specific block # for the + * superblock, then he/she must also specify the block size! + * Otherwise, read the master superblock located at offset + * SUPERBLOCK_OFFSET from the start of the partition. + * + * Note: we only save a backup copy of the superblock if we + * are reading the superblock from the primary superblock location. + */ + if (superblock) { + if (!block_size) { + retval = EXT2_ET_INVALID_ARGUMENT; + goto cleanup; + } + io_channel_set_blksize(fs->io, block_size); + group_block = superblock; + fs->orig_super = 0; + } else { + io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET); + superblock = 1; + group_block = 0; + retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &fs->orig_super); + if (retval) + goto cleanup; + } + retval = io_channel_read_blk(fs->io, superblock, -SUPERBLOCK_SIZE, + fs->super); + if (retval) + goto cleanup; + if (fs->orig_super) + memcpy(fs->orig_super, fs->super, SUPERBLOCK_SIZE); + +#if BB_BIG_ENDIAN + if ((fs->super->s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC)) || + (fs->flags & EXT2_FLAG_SWAP_BYTES)) { + fs->flags |= EXT2_FLAG_SWAP_BYTES; + + ext2fs_swap_super(fs->super); + } +#endif + + if (fs->super->s_magic != EXT2_SUPER_MAGIC) { + retval = EXT2_ET_BAD_MAGIC; + goto cleanup; + } + if (fs->super->s_rev_level > EXT2_LIB_CURRENT_REV) { + retval = EXT2_ET_REV_TOO_HIGH; + goto cleanup; + } + + /* + * Check for feature set incompatibility + */ + if (!(flags & EXT2_FLAG_FORCE)) { + if (fs->super->s_feature_incompat & + ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { + retval = EXT2_ET_UNSUPP_FEATURE; + goto cleanup; + } + if ((flags & EXT2_FLAG_RW) && + (fs->super->s_feature_ro_compat & + ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)) { + retval = EXT2_ET_RO_UNSUPP_FEATURE; + goto cleanup; + } + if (!(flags & EXT2_FLAG_JOURNAL_DEV_OK) && + (fs->super->s_feature_incompat & + EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) { + retval = EXT2_ET_UNSUPP_FEATURE; + goto cleanup; + } + } + + fs->blocksize = EXT2_BLOCK_SIZE(fs->super); + if (fs->blocksize == 0) { + retval = EXT2_ET_CORRUPT_SUPERBLOCK; + goto cleanup; + } + fs->fragsize = EXT2_FRAG_SIZE(fs->super); + fs->inode_blocks_per_group = ((fs->super->s_inodes_per_group * + EXT2_INODE_SIZE(fs->super) + + EXT2_BLOCK_SIZE(fs->super) - 1) / + EXT2_BLOCK_SIZE(fs->super)); + if (block_size) { + if (block_size != fs->blocksize) { + retval = EXT2_ET_UNEXPECTED_BLOCK_SIZE; + goto cleanup; + } + } + /* + * Set the blocksize to the filesystem's blocksize. + */ + io_channel_set_blksize(fs->io, fs->blocksize); + + /* + * If this is an external journal device, don't try to read + * the group descriptors, because they're not there. + */ + if (fs->super->s_feature_incompat & + EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { + fs->group_desc_count = 0; + *ret_fs = fs; + return 0; + } + + /* + * Read group descriptors + */ + blocks_per_group = EXT2_BLOCKS_PER_GROUP(fs->super); + if (blocks_per_group == 0 || + blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(fs->super) || + fs->inode_blocks_per_group > EXT2_MAX_INODES_PER_GROUP(fs->super)) { + retval = EXT2_ET_CORRUPT_SUPERBLOCK; + goto cleanup; + } + fs->group_desc_count = (fs->super->s_blocks_count - + fs->super->s_first_data_block + + blocks_per_group - 1) / blocks_per_group; + fs->desc_blocks = (fs->group_desc_count + + EXT2_DESC_PER_BLOCK(fs->super) - 1) + / EXT2_DESC_PER_BLOCK(fs->super); + retval = ext2fs_get_mem(fs->desc_blocks * fs->blocksize, + &fs->group_desc); + if (retval) + goto cleanup; + if (!group_block) + group_block = fs->super->s_first_data_block; + dest = (char *) fs->group_desc; + groups_per_block = fs->blocksize / sizeof(struct ext2_group_desc); + for (i=0 ; i < fs->desc_blocks; i++) { + blk = ext2fs_descriptor_block_loc(fs, group_block, i); + retval = io_channel_read_blk(fs->io, blk, 1, dest); + if (retval) + goto cleanup; +#if BB_BIG_ENDIAN + if (fs->flags & EXT2_FLAG_SWAP_BYTES) { + gdp = (struct ext2_group_desc *) dest; + for (j=0; j < groups_per_block; j++) + ext2fs_swap_group_desc(gdp++); + } +#endif + dest += fs->blocksize; + } + + *ret_fs = fs; + return 0; +cleanup: + ext2fs_free(fs); + return retval; +} + +/* + * Set/get the filesystem data I/O channel. + * + * These functions are only valid if EXT2_FLAG_IMAGE_FILE is true. + */ +errcode_t ext2fs_get_data_io(ext2_filsys fs, io_channel *old_io) +{ + if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0) + return EXT2_ET_NOT_IMAGE_FILE; + if (old_io) { + *old_io = (fs->image_io == fs->io) ? 0 : fs->io; + } + return 0; +} + +errcode_t ext2fs_set_data_io(ext2_filsys fs, io_channel new_io) +{ + if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0) + return EXT2_ET_NOT_IMAGE_FILE; + fs->io = new_io ? new_io : fs->image_io; + return 0; +} + +errcode_t ext2fs_rewrite_to_io(ext2_filsys fs, io_channel new_io) +{ + if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0) + return EXT2_ET_NOT_IMAGE_FILE; + fs->io = fs->image_io = new_io; + fs->flags |= EXT2_FLAG_DIRTY | EXT2_FLAG_RW | + EXT2_FLAG_BB_DIRTY | EXT2_FLAG_IB_DIRTY; + fs->flags &= ~EXT2_FLAG_IMAGE_FILE; + return 0; +} |