From d1e063beb43e595680c65e3804d1f8ddff53373b Mon Sep 17 00:00:00 2001 From: Guido Guenther Date: Sat, 18 Nov 2006 23:48:07 +0100 Subject: Imported Debian version 0.3.8.8 --- e2fslib/openfs.c | 240 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100644 e2fslib/openfs.c (limited to 'e2fslib/openfs.c') diff --git a/e2fslib/openfs.c b/e2fslib/openfs.c new file mode 100644 index 0000000..042e25a --- /dev/null +++ b/e2fslib/openfs.c @@ -0,0 +1,240 @@ +/* + * 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 +#include +#if HAVE_UNISTD_H +#include +#endif +#include +#include +#if HAVE_SYS_STAT_H +#include +#endif +#if HAVE_SYS_TYPES_H +#include +#endif + +#include "ext2_fs.h" +#include "ext2fs.h" +#include "e2image.h" + +/* + * 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_open(const char *name, int flags, int superblock, + int block_size, io_manager manager, ext2_filsys *ret_fs) +{ + ext2_filsys fs; + errcode_t retval; + int i, j, groups_per_block; + blk_t group_block; + char *dest; + struct ext2_group_desc *gdp; + + EXT2_CHECK_MAGIC(manager, EXT2_ET_MAGIC_IO_MANAGER); + + retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), + (void **) &fs); + if (retval) + return retval; + + memset(fs, 0, sizeof(struct struct_ext2_filsys)); + fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; + fs->flags = flags; + retval = manager->open(name, (flags & EXT2_FLAG_RW) ? IO_FLAG_RW : 0, + &fs->io); + if (retval) + goto cleanup; + fs->io->app_data = fs; + retval = ext2fs_get_mem(strlen(name)+1, (void **) &fs->device_name); + if (retval) + goto cleanup; + strcpy(fs->device_name, name); + retval = ext2fs_get_mem(SUPERBLOCK_SIZE, (void **) &fs->super); + if (retval) + goto cleanup; + if (flags & EXT2_FLAG_IMAGE_FILE) { + retval = ext2fs_get_mem(sizeof(struct ext2_image_hdr), + (void **) &fs->image_header); + if (retval) + goto cleanup; + retval = io_channel_read_blk(fs->io, 0, + -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 + 1; + fs->orig_super = 0; + } else { + io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET); + superblock = 1; + group_block = 0; + retval = ext2fs_get_mem(SUPERBLOCK_SIZE, + (void **) &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); + +#ifdef EXT2FS_ENABLE_SWAPFS + 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) { + printf("%x, %x\n",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 + */ + if ((EXT2_BLOCKS_PER_GROUP(fs->super)) == 0) { + retval = EXT2_ET_CORRUPT_SUPERBLOCK; + goto cleanup; + } + fs->group_desc_count = (fs->super->s_blocks_count - + fs->super->s_first_data_block + + EXT2_BLOCKS_PER_GROUP(fs->super) - 1) + / EXT2_BLOCKS_PER_GROUP(fs->super); + 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, + (void **) &fs->group_desc); + if (retval) + goto cleanup; + if (!group_block) + group_block = fs->super->s_first_data_block + 1; + dest = (char *) fs->group_desc; + for (i=0 ; i < fs->desc_blocks; i++) { + retval = io_channel_read_blk(fs->io, group_block, 1, dest); + if (retval) + goto cleanup; + group_block++; +#ifdef EXT2FS_ENABLE_SWAPFS + if (fs->flags & EXT2_FLAG_SWAP_BYTES) { + gdp = (struct ext2_group_desc *) dest; + groups_per_block = fs->blocksize / + sizeof(struct ext2_group_desc); + 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; +} + -- cgit v1.2.3