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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 09:25:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 09:25:10 +0000
commit5dced3d1b3deca80e01415a2e35dc7972dcbfae7 (patch)
tree6a403684e0978f0287d7f0ec0e5aab1fd31a59e1 /lib/ext2fs/openfs.c
parentInitial commit. (diff)
downloade2fsprogs-5dced3d1b3deca80e01415a2e35dc7972dcbfae7.tar.xz
e2fsprogs-5dced3d1b3deca80e01415a2e35dc7972dcbfae7.zip
Adding upstream version 1.47.0.upstream/1.47.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/ext2fs/openfs.c')
-rw-r--r--lib/ext2fs/openfs.c590
1 files changed, 590 insertions, 0 deletions
diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
new file mode 100644
index 0000000..fd56a9a
--- /dev/null
+++ b/lib/ext2fs/openfs.c
@@ -0,0 +1,590 @@
+/*
+ * 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 Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#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
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+
+#include "ext2_fs.h"
+
+#include "ext2fs.h"
+#include "e2image.h"
+
+blk64_t ext2fs_descriptor_block_loc2(ext2_filsys fs, blk64_t group_block,
+ dgrp_t i)
+{
+ int bg;
+ int has_super = 0, group_zero_adjust = 0;
+ blk64_t ret_blk;
+
+ /*
+ * On a bigalloc FS with 1K blocks, block 0 is reserved for non-ext4
+ * stuff, so adjust for that if we're being asked for group 0.
+ */
+ if (i == 0 && fs->blocksize == 1024 && EXT2FS_CLUSTER_RATIO(fs) > 1)
+ group_zero_adjust = 1;
+
+ if (!ext2fs_has_feature_meta_bg(fs->super) ||
+ (i < fs->super->s_first_meta_bg))
+ return group_block + i + 1 + group_zero_adjust;
+
+ bg = EXT2_DESC_PER_BLOCK(fs->super) * i;
+ if (ext2fs_bg_has_super(fs, bg))
+ has_super = 1;
+ ret_blk = ext2fs_group_first_block2(fs, bg);
+ /*
+ * 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 + has_super + fs->super->s_blocks_per_group) <
+ ext2fs_blocks_count(fs->super))) {
+ ret_blk += fs->super->s_blocks_per_group;
+
+ /*
+ * If we're going to jump forward a block group, make sure
+ * that we adjust has_super to account for the next group's
+ * backup superblock (or lack thereof).
+ */
+ if (ext2fs_bg_has_super(fs, bg + 1))
+ has_super = 1;
+ else
+ has_super = 0;
+ }
+ return ret_blk + has_super + group_zero_adjust;
+}
+
+blk_t ext2fs_descriptor_block_loc(ext2_filsys fs, blk_t group_block, dgrp_t i)
+{
+ return ext2fs_descriptor_block_loc2(fs, group_block, i);
+}
+
+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);
+}
+
+static void block_sha_map_free_entry(void *data)
+{
+ free(data);
+ return;
+}
+
+/*
+ * 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;
+ unsigned int inode_size;
+ __u64 groups_cnt;
+#ifdef WORDS_BIGENDIAN
+ unsigned int groups_per_block;
+ struct ext2_group_desc *gdp;
+ int j;
+#endif
+ char *time_env;
+ int csum_retries = 0;
+
+ 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;
+ if (flags & EXT2_FLAG_THREADS)
+ io_flags |= IO_FLAG_THREADS;
+ 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 (ext2fs_le32_to_cpu(fs->image_header->magic_number) != EXT2_ET_MAGIC_E2IMAGE)
+ return EXT2_ET_MAGIC_E2IMAGE;
+ superblock = 1;
+ block_size = ext2fs_le32_to_cpu(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;
+ }
+retry:
+ 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)) {
+ if (csum_retries++ < 3)
+ goto retry;
+ 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 >
+ (unsigned) (EXT2_MAX_BLOCK_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE)) ||
+ (fs->super->s_log_cluster_size >
+ (unsigned) (EXT2_MAX_CLUSTER_LOG_SIZE - EXT2_MIN_CLUSTER_LOG_SIZE)) ||
+ (fs->super->s_log_block_size > fs->super->s_log_cluster_size) ||
+ (fs->super->s_log_groups_per_flex > 31)) {
+ 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);
+ inode_size = EXT2_INODE_SIZE(fs->super);
+ if ((inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
+ (inode_size > fs->blocksize) ||
+ (inode_size & (inode_size - 1))) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+
+ /* Enforce the block group descriptor size */
+ if (!(flags & EXT2_FLAG_IGNORE_SB_ERRORS) &&
+ ext2fs_has_feature_64bit(fs->super)) {
+ unsigned desc_size = fs->super->s_desc_size;
+
+ if ((desc_size < EXT2_MIN_DESC_SIZE_64BIT) ||
+ (desc_size > EXT2_MAX_DESC_SIZE) ||
+ (desc_size & (desc_size - 1)) != 0) {
+ 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 < 8 ||
+ 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;
+ }
+ groups_cnt = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
+ fs->super->s_first_data_block,
+ blocks_per_group);
+ if (groups_cnt >> 32) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ fs->group_desc_count = groups_cnt;
+ if (!(flags & EXT2_FLAG_IGNORE_SB_ERRORS) &&
+ (__u64)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));
+ if (ext2fs_has_feature_meta_bg(fs->super) &&
+ (fs->super->s_first_meta_bg > fs->desc_blocks) &&
+ !(flags & EXT2_FLAG_IGNORE_SB_ERRORS)) {
+ retval = EXT2_ET_CORRUPT_SUPERBLOCK;
+ goto cleanup;
+ }
+ if (flags & EXT2_FLAG_SUPER_ONLY)
+ goto skip_read_bg;
+ 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) &&
+ !(flags & EXT2_FLAG_IMAGE_FILE)) {
+ 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);
+ if (gdp)
+ 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);
+ io_channel_cache_readahead(fs->io, blk, 1);
+ }
+
+ 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);
+ if (gdp)
+ 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);
+ }
+skip_read_bg:
+ 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);
+ }
+
+ if (ext2fs_has_feature_casefold(fs->super))
+ fs->encoding = ext2fs_load_nls_table(fs->super->s_encoding);
+
+ 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;
+}
+
+/*
+ * 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)
+{
+ errcode_t err;
+
+ if ((fs->flags & EXT2_FLAG_IMAGE_FILE) == 0)
+ return EXT2_ET_NOT_IMAGE_FILE;
+ err = io_channel_set_blksize(new_io, fs->blocksize);
+ if (err)
+ return err;
+ if ((new_io == fs->image_io) || (new_io == fs->io))
+ return 0;
+ if ((fs->image_io != fs->io) &&
+ fs->image_io)
+ io_channel_close(fs->image_io);
+ if (fs->io)
+ io_channel_close(fs->io);
+ 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;
+}