__u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group) { __u16 crc = 0; struct ext2_group_desc *desc; size_t size; size = fs->super->s_desc_size; if (size < EXT2_MIN_DESC_SIZE) size = EXT2_MIN_DESC_SIZE; if (size > sizeof(struct ext4_group_desc)) { printf("%s: illegal s_desc_size(%zd)\n", __func__, size); size = sizeof(struct ext4_group_desc); } desc = ext2fs_group_desc(fs, fs->group_desc, group); if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) { size_t offset = offsetof(struct ext2_group_desc, bg_checksum); #ifdef WORDS_BIGENDIAN struct ext4_group_desc swabdesc; /* Have to swab back to little-endian to do the checksum */ memcpy(&swabdesc, desc, size); ext2fs_swap_group_desc2(fs, (struct ext2_group_desc *) &swabdesc); desc = (struct ext2_group_desc *) &swabdesc; group = ext2fs_swab32(group); #endif crc = ext2fs_crc16(~0, fs->super->s_uuid, sizeof(fs->super->s_uuid)); crc = ext2fs_crc16(crc, &group, sizeof(group)); crc = ext2fs_crc16(crc, desc, offset); offset += sizeof(desc->bg_checksum); /* skip checksum */ /* for checksum of struct ext4_group_desc do the rest...*/ if (offset < size) { crc = ext2fs_crc16(crc, (char *)desc + offset, size - offset); } }
errcode_t ext2fs_flush2(ext2_filsys fs, int flags) { dgrp_t i; errcode_t retval; unsigned long fs_state; __u32 feature_incompat; struct ext2_super_block *super_shadow = 0; struct ext2_group_desc *group_shadow = 0; #ifdef WORDS_BIGENDIAN struct ext2_group_desc *gdp; dgrp_t j; #endif char *group_ptr; blk64_t old_desc_blocks; struct ext2fs_numeric_progress_struct progress; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); fs_state = fs->super->s_state; feature_incompat = fs->super->s_feature_incompat; fs->super->s_wtime = fs->now ? fs->now : time(NULL); fs->super->s_block_group_nr = 0; /* * If the write_bitmaps() function is present, call it to * flush the bitmaps. This is done this way so that a simple * program that doesn't mess with the bitmaps doesn't need to * drag in the bitmaps.c code. * * Bitmap checksums live in the group descriptor, so the * bitmaps need to be written before the descriptors. */ if (fs->write_bitmaps) { retval = fs->write_bitmaps(fs); if (retval) goto errout; } /* Prepare the group descriptors for writing */ #ifdef WORDS_BIGENDIAN retval = EXT2_ET_NO_MEMORY; retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super_shadow); if (retval) goto errout; retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, &group_shadow); if (retval) goto errout; memcpy(super_shadow, fs->super, sizeof(struct ext2_super_block)); memcpy(group_shadow, fs->group_desc, (size_t) fs->blocksize * fs->desc_blocks); /* swap the group descriptors */ for (j = 0; j < fs->group_desc_count; j++) { gdp = ext2fs_group_desc(fs, group_shadow, j); ext2fs_swap_group_desc2(fs, gdp); } #else super_shadow = fs->super; group_shadow = ext2fs_group_desc(fs, fs->group_desc, 0); #endif /* * Set the state of the FS to be non-valid. (The state has * already been backed up earlier, and will be restored after * we write out the backup superblocks.) */ fs->super->s_state &= ~EXT2_VALID_FS; ext2fs_clear_feature_journal_needs_recovery(fs->super); /* * If this is an external journal device, don't write out the * block group descriptors or any of the backup superblocks */ if (ext2fs_has_feature_journal_dev(fs->super)) goto write_primary_superblock_only; /* * Write out the master group descriptors, and the backup * superblocks and group descriptors. */ group_ptr = (char *) group_shadow; if (ext2fs_has_feature_meta_bg(fs->super)) { old_desc_blocks = fs->super->s_first_meta_bg; if (old_desc_blocks > fs->desc_blocks) old_desc_blocks = fs->desc_blocks; } else old_desc_blocks = fs->desc_blocks; if (fs->progress_ops && fs->progress_ops->init) (fs->progress_ops->init)(fs, &progress, NULL, fs->group_desc_count); for (i = 0; i < fs->group_desc_count; i++) { blk64_t super_blk, old_desc_blk, new_desc_blk; if (fs->progress_ops && fs->progress_ops->update) (fs->progress_ops->update)(fs, &progress, i); ext2fs_super_and_bgd_loc2(fs, i, &super_blk, &old_desc_blk, &new_desc_blk, 0); if (!(fs->flags & EXT2_FLAG_MASTER_SB_ONLY) &&i && super_blk) { retval = write_backup_super(fs, i, super_blk, super_shadow); if (retval) goto errout; } if (fs->flags & EXT2_FLAG_SUPER_ONLY) continue; if ((old_desc_blk) && (!(fs->flags & EXT2_FLAG_MASTER_SB_ONLY) || (i == 0))) { retval = io_channel_write_blk64(fs->io, old_desc_blk, old_desc_blocks, group_ptr); if (retval) goto errout; } if (new_desc_blk) { int meta_bg = i / EXT2_DESC_PER_BLOCK(fs->super); retval = io_channel_write_blk64(fs->io, new_desc_blk, 1, group_ptr + (meta_bg*fs->blocksize)); if (retval) goto errout; } } if (fs->progress_ops && fs->progress_ops->close) (fs->progress_ops->close)(fs, &progress, NULL); write_primary_superblock_only: /* * Write out master superblock. This has to be done * separately, since it is located at a fixed location * (SUPERBLOCK_OFFSET). We flush all other pending changes * out to disk first, just to avoid a race condition with an * insy-tinsy window.... */ fs->super->s_block_group_nr = 0; fs->super->s_state = fs_state; fs->super->s_feature_incompat = feature_incompat; #ifdef WORDS_BIGENDIAN *super_shadow = *fs->super; ext2fs_swap_super(super_shadow); #endif retval = ext2fs_superblock_csum_set(fs, super_shadow); if (retval) return retval; if (!(flags & EXT2_FLAG_FLUSH_NO_SYNC)) retval = io_channel_flush(fs->io); retval = write_primary_superblock(fs, super_shadow); if (retval) goto errout; fs->flags &= ~EXT2_FLAG_DIRTY; if (!(flags & EXT2_FLAG_FLUSH_NO_SYNC)) retval = io_channel_flush(fs->io); errout: fs->super->s_state = fs_state; #ifdef WORDS_BIGENDIAN if (super_shadow) ext2fs_free_mem(&super_shadow); if (group_shadow) ext2fs_free_mem(&group_shadow); #endif return retval; }
/* * 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 * EXT2_FLAG_SKIP_MMP - Open without multi-mount protection check. * EXT2_FLAG_64BITS - Allow 64-bit bitfields (needed for large * filesystems) */ 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, first_meta_bg; __u32 features; unsigned int blocks_per_group, io_flags; blk64_t group_block, blk; char *dest, *cp; int group_zero_adjust = 0; #ifdef WORDS_BIGENDIAN unsigned int groups_per_block; struct ext2_group_desc *gdp; int j; #endif char *time_env; 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; /* don't overwrite sb backups unless flag is explicitly cleared */ fs->flags |= EXT2_FLAG_MASTER_SB_ONLY; fs->umask = 022; time_env = getenv("E2FSPROGS_FAKE_TIME"); if (time_env) fs->now = strtoul(time_env, NULL, 0); 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; } io_flags = 0; if (flags & EXT2_FLAG_RW) io_flags |= IO_FLAG_RW; if (flags & EXT2_FLAG_EXCLUSIVE) io_flags |= IO_FLAG_EXCLUSIVE; if (flags & EXT2_FLAG_DIRECT_IO) io_flags |= IO_FLAG_DIRECT_IO; retval = manager->open(fs->device_name, io_flags, &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 = io_channel_alloc_buf(fs->io, -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 (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS)) { retval = 0; if (!ext2fs_verify_csum_type(fs, fs->super)) retval = EXT2_ET_UNKNOWN_CSUM; if (!ext2fs_superblock_csum_verify(fs, fs->super)) retval = EXT2_ET_SB_CSUM_INVALID; } #ifdef WORDS_BIGENDIAN fs->flags |= EXT2_FLAG_SWAP_BYTES; ext2fs_swap_super(fs->super); #else if (fs->flags & EXT2_FLAG_SWAP_BYTES) { retval = EXT2_ET_UNIMPLEMENTED; goto cleanup; } #endif if (fs->super->s_magic != EXT2_SUPER_MAGIC) retval = EXT2_ET_BAD_MAGIC; if (retval) 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)) { features = fs->super->s_feature_incompat; #ifdef EXT2_LIB_SOFTSUPP_INCOMPAT if (flags & EXT2_FLAG_SOFTSUPP_FEATURES) features &= ~EXT2_LIB_SOFTSUPP_INCOMPAT; #endif if (features & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { retval = EXT2_ET_UNSUPP_FEATURE; goto cleanup; } features = fs->super->s_feature_ro_compat; #ifdef EXT2_LIB_SOFTSUPP_RO_COMPAT if (flags & EXT2_FLAG_SOFTSUPP_FEATURES) features &= ~EXT2_LIB_SOFTSUPP_RO_COMPAT; #endif if ((flags & EXT2_FLAG_RW) && (features & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)) { retval = EXT2_ET_RO_UNSUPP_FEATURE; goto cleanup; } if (!(flags & EXT2_FLAG_JOURNAL_DEV_OK) && ext2fs_has_feature_journal_dev(fs->super)) { retval = EXT2_ET_UNSUPP_FEATURE; goto cleanup; } } if ((fs->super->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) > EXT2_MAX_BLOCK_LOG_SIZE) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } /* * bigalloc requires cluster-aware bitfield operations, which at the * moment means we need EXT2_FLAG_64BITS. */ if (ext2fs_has_feature_bigalloc(fs->super) && !(flags & EXT2_FLAG_64BITS)) { retval = EXT2_ET_CANT_USE_LEGACY_BITMAPS; goto cleanup; } if (!ext2fs_has_feature_bigalloc(fs->super) && (fs->super->s_log_block_size != fs->super->s_log_cluster_size)) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(fs->super); if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } /* Enforce the block group descriptor size */ if (ext2fs_has_feature_64bit(fs->super)) { if (fs->super->s_desc_size < EXT2_MIN_DESC_SIZE_64BIT) { retval = EXT2_ET_BAD_DESC_SIZE; goto cleanup; } } else { if (fs->super->s_desc_size && fs->super->s_desc_size != EXT2_MIN_DESC_SIZE) { retval = EXT2_ET_BAD_DESC_SIZE; goto cleanup; } } fs->cluster_ratio_bits = fs->super->s_log_cluster_size - fs->super->s_log_block_size; if (EXT2_BLOCKS_PER_GROUP(fs->super) != EXT2_CLUSTERS_PER_GROUP(fs->super) << fs->cluster_ratio_bits) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->inode_blocks_per_group = ((EXT2_INODES_PER_GROUP(fs->super) * 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 (ext2fs_has_feature_journal_dev(fs->super)) { fs->group_desc_count = 0; *ret_fs = fs; return 0; } if (EXT2_INODES_PER_GROUP(fs->super) == 0) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } /* Precompute the FS UUID to seed other checksums */ ext2fs_init_csum_seed(fs); /* * 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) || EXT2_DESC_PER_BLOCK(fs->super) == 0 || fs->super->s_first_data_block >= ext2fs_blocks_count(fs->super)) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block, blocks_per_group); if (fs->group_desc_count * EXT2_INODES_PER_GROUP(fs->super) != fs->super->s_inodes_count) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, EXT2_DESC_PER_BLOCK(fs->super)); retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, &fs->group_desc); if (retval) goto cleanup; if (!group_block) group_block = fs->super->s_first_data_block; /* * On a FS with a 1K blocksize, block 0 is reserved for bootloaders * so we must increment block numbers to any group 0 items. * * However, we cannot touch group_block directly because in the meta_bg * case, the ext2fs_descriptor_block_loc2() function will interpret * group_block != s_first_data_block to mean that we want to access the * backup group descriptors. This is not what we want if the caller * set superblock == 0 (i.e. auto-detect the superblock), which is * what's going on here. */ if (group_block == 0 && fs->blocksize == 1024) group_zero_adjust = 1; dest = (char *) fs->group_desc; #ifdef WORDS_BIGENDIAN groups_per_block = EXT2_DESC_PER_BLOCK(fs->super); #endif if (ext2fs_has_feature_meta_bg(fs->super)) { first_meta_bg = fs->super->s_first_meta_bg; if (first_meta_bg > fs->desc_blocks) first_meta_bg = fs->desc_blocks; } else first_meta_bg = fs->desc_blocks; if (first_meta_bg) { retval = io_channel_read_blk(fs->io, group_block + group_zero_adjust + 1, first_meta_bg, dest); if (retval) goto cleanup; #ifdef WORDS_BIGENDIAN gdp = (struct ext2_group_desc *) dest; for (j=0; j < groups_per_block*first_meta_bg; j++) { gdp = ext2fs_group_desc(fs, fs->group_desc, j); ext2fs_swap_group_desc2(fs, gdp); } #endif dest += fs->blocksize*first_meta_bg; } for (i=first_meta_bg ; i < fs->desc_blocks; i++) { blk = ext2fs_descriptor_block_loc2(fs, group_block, i); retval = io_channel_read_blk64(fs->io, blk, 1, dest); if (retval) goto cleanup; #ifdef WORDS_BIGENDIAN for (j=0; j < groups_per_block; j++) { gdp = ext2fs_group_desc(fs, fs->group_desc, i * groups_per_block + j); ext2fs_swap_group_desc2(fs, gdp); } #endif dest += fs->blocksize; } fs->stride = fs->super->s_raid_stride; /* * If recovery is from backup superblock, Clear _UNININT flags & * reset bg_itable_unused to zero */ if (superblock > 1 && ext2fs_has_group_desc_csum(fs)) { dgrp_t group; for (group = 0; group < fs->group_desc_count; group++) { ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT); ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT); ext2fs_bg_itable_unused_set(fs, group, 0); /* The checksum will be reset later, but fix it here * anyway to avoid printing a lot of spurious errors. */ ext2fs_group_desc_csum_set(fs, group); } if (fs->flags & EXT2_FLAG_RW) ext2fs_mark_super_dirty(fs); } if (ext2fs_has_feature_mmp(fs->super) && !(flags & EXT2_FLAG_SKIP_MMP) && (flags & (EXT2_FLAG_RW | EXT2_FLAG_EXCLUSIVE))) { retval = ext2fs_mmp_start(fs); if (retval) { fs->flags |= EXT2_FLAG_SKIP_MMP; /* just do cleanup */ ext2fs_mmp_stop(fs); goto cleanup; } } if (fs->flags & EXT2_FLAG_SHARE_DUP) { fs->block_sha_map = ext2fs_hashmap_create(ext2fs_djb2_hash, block_sha_map_free_entry, 4096); if (!fs->block_sha_map) { retval = EXT2_ET_NO_MEMORY; goto cleanup; } ext2fs_set_feature_shared_blocks(fs->super); } fs->flags &= ~EXT2_FLAG_NOFREE_ON_ERROR; *ret_fs = fs; return 0; cleanup: if (!(flags & EXT2_FLAG_NOFREE_ON_ERROR)) { ext2fs_free(fs); fs = NULL; } *ret_fs = fs; return retval; }
/* * 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_channel * io, ext2_filsys *ret_fs) { ext2_filsys fs; io_manager manager = (*io)->manager; errcode_t retval; unsigned long i, first_meta_bg; __u32 features; int groups_per_block, blocks_per_group, io_flags; blk64_t group_block, blk; char *dest, *cp; #ifdef WORDS_BIGENDIAN struct ext2_group_desc *gdp; int j; #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->io = *io; fs->flags = flags; /* don't overwrite sb backups unless flag is explicitly cleared */ fs->flags |= EXT2_FLAG_MASTER_SB_ONLY; 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; } io_flags = 0; if (flags & EXT2_FLAG_RW) io_flags |= IO_FLAG_RW; if (flags & EXT2_FLAG_EXCLUSIVE) io_flags |= IO_FLAG_EXCLUSIVE; if (flags & EXT2_FLAG_DIRECT_IO) io_flags |= IO_FLAG_DIRECT_IO; retval = manager->open(fs->device_name, io_flags, &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_memalign(SUPERBLOCK_SIZE, 512, &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); #ifdef WORDS_BIGENDIAN fs->flags |= EXT2_FLAG_SWAP_BYTES; ext2fs_swap_super(fs->super); #else if (fs->flags & EXT2_FLAG_SWAP_BYTES) { retval = EXT2_ET_UNIMPLEMENTED; goto cleanup; } #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)) { features = fs->super->s_feature_incompat; #ifdef EXT2_LIB_SOFTSUPP_INCOMPAT if (flags & EXT2_FLAG_SOFTSUPP_FEATURES) features &= !EXT2_LIB_SOFTSUPP_INCOMPAT; #endif if (features & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { retval = EXT2_ET_UNSUPP_FEATURE; goto cleanup; } features = fs->super->s_feature_ro_compat; #ifdef EXT2_LIB_SOFTSUPP_RO_COMPAT if (flags & EXT2_FLAG_SOFTSUPP_FEATURES) features &= !EXT2_LIB_SOFTSUPP_RO_COMPAT; #endif if ((flags & EXT2_FLAG_RW) && (features & ~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; } } if ((fs->super->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) > EXT2_MAX_BLOCK_LOG_SIZE) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->blocksize = EXT2_BLOCK_SIZE(fs->super); if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->clustersize = EXT2_CLUSTER_SIZE(fs->super); fs->inode_blocks_per_group = ((EXT2_INODES_PER_GROUP(fs->super) * 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; } if (EXT2_INODES_PER_GROUP(fs->super) == 0) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } /* * 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) || EXT2_DESC_PER_BLOCK(fs->super) == 0 || fs->super->s_first_data_block >= ext2fs_blocks_count(fs->super)) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block, blocks_per_group); if (fs->group_desc_count * EXT2_INODES_PER_GROUP(fs->super) != fs->super->s_inodes_count) { retval = EXT2_ET_CORRUPT_SUPERBLOCK; goto cleanup; } fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, EXT2_DESC_PER_BLOCK(fs->super)); retval = ext2fs_get_array(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 = EXT2_DESC_PER_BLOCK(fs->super); if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) first_meta_bg = fs->super->s_first_meta_bg; else first_meta_bg = fs->desc_blocks; if (first_meta_bg) { retval = io_channel_read_blk(fs->io, group_block+1, first_meta_bg, dest); if (retval) goto cleanup; #ifdef WORDS_BIGENDIAN gdp = (struct ext2_group_desc *) dest; for (j=0; j < groups_per_block*first_meta_bg; j++) { gdp = ext2fs_group_desc(fs, fs->group_desc, j); ext2fs_swap_group_desc2(fs, gdp); } #endif dest += fs->blocksize*first_meta_bg; } for (i=first_meta_bg ; i < fs->desc_blocks; i++) { blk = ext2fs_descriptor_block_loc2(fs, group_block, i); retval = io_channel_read_blk64(fs->io, blk, 1, dest); if (retval) goto cleanup; #ifdef WORDS_BIGENDIAN for (j=0; j < groups_per_block; j++) { /* The below happens to work... be careful. */ gdp = ext2fs_group_desc(fs, fs->group_desc, j); ext2fs_swap_group_desc2(fs, gdp); } #endif dest += fs->blocksize; } fs->stride = fs->super->s_raid_stride; /* * If recovery is from backup superblock, Clear _UNININT flags & * reset bg_itable_unused to zero */ if (superblock > 1 && EXT2_HAS_RO_COMPAT_FEATURE(fs->super, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { dgrp_t group; for (group = 0; group < fs->group_desc_count; group++) { ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT); ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT); ext2fs_bg_itable_unused_set(fs, group, 0); } ext2fs_mark_super_dirty(fs); } fs->flags &= ~EXT2_FLAG_NOFREE_ON_ERROR; *ret_fs = fs; return 0; cleanup: if (flags & EXT2_FLAG_NOFREE_ON_ERROR) *ret_fs = fs; else ext2fs_free(fs); return retval; }
void ext2fs_swap_group_desc(struct ext2_group_desc *gdp) { return ext2fs_swap_group_desc2(0, gdp); }