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-rw-r--r--lib/ext2fs/rw_bitmaps.c682
1 files changed, 682 insertions, 0 deletions
diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
new file mode 100644
index 0000000..1fe65f7
--- /dev/null
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -0,0 +1,682 @@
+/*
+ * 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 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>
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_PTHREAD_H
+#include <pthread.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+#include "e2image.h"
+
+#ifdef HAVE_PTHREAD
+typedef pthread_mutex_t mutex_t;
+
+static void unix_pthread_mutex_lock(mutex_t *mutex)
+{
+ if (mutex)
+ pthread_mutex_lock(mutex);
+}
+static void unix_pthread_mutex_unlock(mutex_t *mutex)
+{
+ if (mutex)
+ pthread_mutex_unlock(mutex);
+}
+#else
+typedef int mutex_t;
+#define unix_pthread_mutex_lock(mutex_t) do {} while (0)
+#define unix_pthread_mutex_unlock(mutex_t) do {} while (0)
+#endif
+
+static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
+{
+ dgrp_t i;
+ unsigned int j;
+ int block_nbytes, inode_nbytes;
+ unsigned int nbits;
+ errcode_t retval;
+ char *block_buf = NULL, *inode_buf = NULL;
+ int csum_flag;
+ blk64_t blk;
+ blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
+ ext2_ino_t ino_itr = 1;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if (!(fs->flags & EXT2_FLAG_RW))
+ return EXT2_ET_RO_FILSYS;
+
+ csum_flag = ext2fs_has_group_desc_csum(fs);
+
+ inode_nbytes = block_nbytes = 0;
+ if (do_block) {
+ block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
+ retval = io_channel_alloc_buf(fs->io, 0, &block_buf);
+ if (retval)
+ goto errout;
+ memset(block_buf, 0xff, fs->blocksize);
+ }
+ if (do_inode) {
+ inode_nbytes = (size_t)
+ ((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
+ retval = io_channel_alloc_buf(fs->io, 0, &inode_buf);
+ if (retval)
+ goto errout;
+ memset(inode_buf, 0xff, fs->blocksize);
+ }
+
+ for (i = 0; i < fs->group_desc_count; i++) {
+ if (!do_block)
+ goto skip_block_bitmap;
+
+ if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)
+ )
+ goto skip_this_block_bitmap;
+
+ retval = ext2fs_get_block_bitmap_range2(fs->block_map,
+ blk_itr, block_nbytes << 3, block_buf);
+ if (retval)
+ goto errout;
+
+ if (i == fs->group_desc_count - 1) {
+ /* Force bitmap padding for the last group */
+ nbits = EXT2FS_NUM_B2C(fs,
+ ((ext2fs_blocks_count(fs->super)
+ - (__u64) fs->super->s_first_data_block)
+ % (__u64) EXT2_BLOCKS_PER_GROUP(fs->super)));
+ if (nbits)
+ for (j = nbits; j < fs->blocksize * 8; j++)
+ ext2fs_set_bit(j, block_buf);
+ }
+
+ retval = ext2fs_block_bitmap_csum_set(fs, i, block_buf,
+ block_nbytes);
+ if (retval)
+ return retval;
+ ext2fs_group_desc_csum_set(fs, i);
+ fs->flags |= EXT2_FLAG_DIRTY;
+
+ blk = ext2fs_block_bitmap_loc(fs, i);
+ if (blk && blk < ext2fs_blocks_count(fs->super)) {
+ retval = io_channel_write_blk64(fs->io, blk, 1,
+ block_buf);
+ if (retval) {
+ retval = EXT2_ET_BLOCK_BITMAP_WRITE;
+ goto errout;
+ }
+ }
+ skip_this_block_bitmap:
+ blk_itr += block_nbytes << 3;
+ skip_block_bitmap:
+
+ if (!do_inode)
+ continue;
+
+ if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)
+ )
+ goto skip_this_inode_bitmap;
+
+ retval = ext2fs_get_inode_bitmap_range2(fs->inode_map,
+ ino_itr, inode_nbytes << 3, inode_buf);
+ if (retval)
+ goto errout;
+
+ retval = ext2fs_inode_bitmap_csum_set(fs, i, inode_buf,
+ inode_nbytes);
+ if (retval)
+ goto errout;
+ ext2fs_group_desc_csum_set(fs, i);
+ fs->flags |= EXT2_FLAG_DIRTY;
+
+ blk = ext2fs_inode_bitmap_loc(fs, i);
+ if (blk && blk < ext2fs_blocks_count(fs->super)) {
+ retval = io_channel_write_blk64(fs->io, blk, 1,
+ inode_buf);
+ if (retval) {
+ retval = EXT2_ET_INODE_BITMAP_WRITE;
+ goto errout;
+ }
+ }
+ skip_this_inode_bitmap:
+ ino_itr += inode_nbytes << 3;
+
+ }
+ if (do_block) {
+ fs->flags &= ~EXT2_FLAG_BB_DIRTY;
+ ext2fs_free_mem(&block_buf);
+ }
+ if (do_inode) {
+ fs->flags &= ~EXT2_FLAG_IB_DIRTY;
+ ext2fs_free_mem(&inode_buf);
+ }
+ return 0;
+errout:
+ if (inode_buf)
+ ext2fs_free_mem(&inode_buf);
+ if (block_buf)
+ ext2fs_free_mem(&block_buf);
+ return retval;
+}
+
+static errcode_t mark_uninit_bg_group_blocks(ext2_filsys fs)
+{
+ dgrp_t i;
+ blk64_t blk;
+ ext2fs_block_bitmap bmap = fs->block_map;
+
+ for (i = 0; i < fs->group_desc_count; i++) {
+ if (!ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT))
+ continue;
+
+ ext2fs_reserve_super_and_bgd(fs, i, bmap);
+
+ /*
+ * Mark the blocks used for the inode table
+ */
+ blk = ext2fs_inode_table_loc(fs, i);
+ if (blk)
+ ext2fs_mark_block_bitmap_range2(bmap, blk,
+ fs->inode_blocks_per_group);
+
+ /*
+ * Mark block used for the block bitmap
+ */
+ blk = ext2fs_block_bitmap_loc(fs, i);
+ if (blk && blk < ext2fs_blocks_count(fs->super))
+ ext2fs_mark_block_bitmap2(bmap, blk);
+
+ /*
+ * Mark block used for the inode bitmap
+ */
+ blk = ext2fs_inode_bitmap_loc(fs, i);
+ if (blk && blk < ext2fs_blocks_count(fs->super))
+ ext2fs_mark_block_bitmap2(bmap, blk);
+ }
+ return 0;
+}
+
+static int bitmap_tail_verify(unsigned char *bitmap, int first, int last)
+{
+ int i;
+
+ for (i = first; i <= last; i++)
+ if (bitmap[i] != 0xff)
+ return 0;
+ return 1;
+}
+
+static errcode_t read_bitmaps_range_prepare(ext2_filsys fs, int flags)
+{
+ errcode_t retval;
+ int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
+ int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
+ char *buf;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ if ((block_nbytes > (int) fs->blocksize) ||
+ (inode_nbytes > (int) fs->blocksize))
+ return EXT2_ET_CORRUPT_SUPERBLOCK;
+
+ fs->write_bitmaps = ext2fs_write_bitmaps;
+
+ retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
+ if (retval)
+ return retval;
+
+ if (flags & EXT2FS_BITMAPS_BLOCK) {
+ if (fs->block_map)
+ ext2fs_free_block_bitmap(fs->block_map);
+ strcpy(buf, "block bitmap for ");
+ strcat(buf, fs->device_name);
+ retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
+ if (retval)
+ goto cleanup;
+ }
+
+ if (flags & EXT2FS_BITMAPS_INODE) {
+ if (fs->inode_map)
+ ext2fs_free_inode_bitmap(fs->inode_map);
+ strcpy(buf, "inode bitmap for ");
+ strcat(buf, fs->device_name);
+ retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
+ if (retval)
+ goto cleanup;
+ }
+ ext2fs_free_mem(&buf);
+ return retval;
+
+cleanup:
+ if (flags & EXT2FS_BITMAPS_BLOCK) {
+ ext2fs_free_block_bitmap(fs->block_map);
+ fs->block_map = 0;
+ }
+ if (flags & EXT2FS_BITMAPS_INODE) {
+ ext2fs_free_inode_bitmap(fs->inode_map);
+ fs->inode_map = 0;
+ }
+ ext2fs_free_mem(&buf);
+ return retval;
+}
+
+static errcode_t read_bitmaps_range_start(ext2_filsys fs, int flags,
+ dgrp_t start, dgrp_t end,
+ mutex_t *mutex,
+ int *tail_flags)
+{
+ dgrp_t i;
+ char *block_bitmap = 0, *inode_bitmap = 0;
+ errcode_t retval = 0;
+ int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
+ int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
+ int csum_flag;
+ unsigned int cnt;
+ blk64_t blk;
+ blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
+ blk64_t blk_cnt;
+ ext2_ino_t ino_itr = 1;
+ ext2_ino_t ino_cnt;
+
+ csum_flag = ext2fs_has_group_desc_csum(fs);
+
+ if (flags & EXT2FS_BITMAPS_BLOCK) {
+ retval = io_channel_alloc_buf(fs->io, 0, &block_bitmap);
+ if (retval)
+ goto cleanup;
+ } else {
+ block_nbytes = 0;
+ }
+
+ if (flags & EXT2FS_BITMAPS_INODE) {
+ retval = io_channel_alloc_buf(fs->io, 0, &inode_bitmap);
+ if (retval)
+ goto cleanup;
+ } else {
+ inode_nbytes = 0;
+ }
+
+ /* io should be null */
+ if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
+ blk = (ext2fs_le32_to_cpu(fs->image_header->offset_inodemap) / fs->blocksize);
+ ino_cnt = fs->super->s_inodes_count;
+ while (inode_bitmap && ino_cnt > 0) {
+ retval = io_channel_read_blk64(fs->image_io, blk++,
+ 1, inode_bitmap);
+ if (retval)
+ goto cleanup;
+ cnt = fs->blocksize << 3;
+ if (cnt > ino_cnt)
+ cnt = ino_cnt;
+ retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
+ ino_itr, cnt, inode_bitmap);
+ if (retval)
+ goto cleanup;
+ ino_itr += cnt;
+ ino_cnt -= cnt;
+ }
+ blk = (ext2fs_le32_to_cpu(fs->image_header->offset_blockmap) /
+ fs->blocksize);
+ blk_cnt = EXT2_GROUPS_TO_CLUSTERS(fs->super,
+ fs->group_desc_count);
+ while (block_bitmap && blk_cnt > 0) {
+ retval = io_channel_read_blk64(fs->image_io, blk++,
+ 1, block_bitmap);
+ if (retval)
+ goto cleanup;
+ cnt = fs->blocksize << 3;
+ if (cnt > blk_cnt)
+ cnt = blk_cnt;
+ retval = ext2fs_set_block_bitmap_range2(fs->block_map,
+ blk_itr, cnt, block_bitmap);
+ if (retval)
+ goto cleanup;
+ blk_itr += cnt;
+ blk_cnt -= cnt;
+ }
+ goto cleanup;
+ }
+
+ blk_itr += ((blk64_t)start * (block_nbytes << 3));
+ ino_itr += ((blk64_t)start * (inode_nbytes << 3));
+ for (i = start; i <= end; i++) {
+ if (block_bitmap) {
+ blk = ext2fs_block_bitmap_loc(fs, i);
+ if ((csum_flag &&
+ ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) &&
+ ext2fs_group_desc_csum_verify(fs, i)) ||
+ (blk >= ext2fs_blocks_count(fs->super)))
+ blk = 0;
+ if (blk) {
+ retval = io_channel_read_blk64(fs->io, blk,
+ 1, block_bitmap);
+ if (retval) {
+ retval = EXT2_ET_BLOCK_BITMAP_READ;
+ goto cleanup;
+ }
+ /* verify block bitmap checksum */
+ if (!(fs->flags &
+ EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+ !ext2fs_block_bitmap_csum_verify(fs, i,
+ block_bitmap, block_nbytes)) {
+ retval =
+ EXT2_ET_BLOCK_BITMAP_CSUM_INVALID;
+ goto cleanup;
+ }
+ if (!bitmap_tail_verify((unsigned char *) block_bitmap,
+ block_nbytes, fs->blocksize - 1))
+ *tail_flags |= EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
+ } else
+ memset(block_bitmap, 0, block_nbytes);
+ cnt = block_nbytes << 3;
+ unix_pthread_mutex_lock(mutex);
+ retval = ext2fs_set_block_bitmap_range2(fs->block_map,
+ blk_itr, cnt, block_bitmap);
+ unix_pthread_mutex_unlock(mutex);
+ if (retval)
+ goto cleanup;
+ blk_itr += block_nbytes << 3;
+ }
+ if (inode_bitmap) {
+ blk = ext2fs_inode_bitmap_loc(fs, i);
+ if ((csum_flag &&
+ ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) &&
+ ext2fs_group_desc_csum_verify(fs, i)) ||
+ (blk >= ext2fs_blocks_count(fs->super)))
+ blk = 0;
+ if (blk) {
+ retval = io_channel_read_blk64(fs->io, blk,
+ 1, inode_bitmap);
+ if (retval) {
+ retval = EXT2_ET_INODE_BITMAP_READ;
+ goto cleanup;
+ }
+
+ /* verify inode bitmap checksum */
+ if (!(fs->flags &
+ EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+ !ext2fs_inode_bitmap_csum_verify(fs, i,
+ inode_bitmap, inode_nbytes)) {
+ retval =
+ EXT2_ET_INODE_BITMAP_CSUM_INVALID;
+ goto cleanup;
+ }
+ if (!bitmap_tail_verify((unsigned char *) inode_bitmap,
+ inode_nbytes, fs->blocksize - 1))
+ *tail_flags |= EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
+ } else
+ memset(inode_bitmap, 0, inode_nbytes);
+ cnt = inode_nbytes << 3;
+ unix_pthread_mutex_lock(mutex);
+ retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
+ ino_itr, cnt, inode_bitmap);
+ unix_pthread_mutex_unlock(mutex);
+ if (retval)
+ goto cleanup;
+ ino_itr += inode_nbytes << 3;
+ }
+ }
+
+cleanup:
+ if (inode_bitmap)
+ ext2fs_free_mem(&inode_bitmap);
+ if (block_bitmap)
+ ext2fs_free_mem(&block_bitmap);
+ return retval;
+}
+
+static errcode_t read_bitmaps_range_end(ext2_filsys fs, int flags,
+ int tail_flags)
+{
+ errcode_t retval;
+
+ /* Mark group blocks for any BLOCK_UNINIT groups */
+ if (flags & EXT2FS_BITMAPS_BLOCK) {
+ retval = mark_uninit_bg_group_blocks(fs);
+ if (retval)
+ return retval;
+ fs->flags &= ~EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
+ }
+ if (flags & EXT2FS_BITMAPS_INODE)
+ fs->flags &= ~EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
+ fs->flags |= tail_flags;
+
+ return 0;
+}
+
+static void read_bitmaps_cleanup_on_error(ext2_filsys fs, int flags)
+{
+ if (flags & EXT2FS_BITMAPS_BLOCK) {
+ ext2fs_free_block_bitmap(fs->block_map);
+ fs->block_map = 0;
+ }
+ if (flags & EXT2FS_BITMAPS_INODE) {
+ ext2fs_free_inode_bitmap(fs->inode_map);
+ fs->inode_map = 0;
+ }
+}
+
+static errcode_t read_bitmaps_range(ext2_filsys fs, int flags,
+ dgrp_t start, dgrp_t end)
+{
+ errcode_t retval;
+ int tail_flags = 0;
+
+ retval = read_bitmaps_range_prepare(fs, flags);
+ if (retval)
+ return retval;
+
+ retval = read_bitmaps_range_start(fs, flags, start, end,
+ NULL, &tail_flags);
+ if (retval == 0)
+ retval = read_bitmaps_range_end(fs, flags, tail_flags);
+ if (retval)
+ read_bitmaps_cleanup_on_error(fs, flags);
+ return retval;
+}
+
+#ifdef HAVE_PTHREAD
+struct read_bitmaps_thread_info {
+ ext2_filsys rbt_fs;
+ int rbt_flags;
+ dgrp_t rbt_grp_start;
+ dgrp_t rbt_grp_end;
+ errcode_t rbt_retval;
+ pthread_mutex_t *rbt_mutex;
+ int rbt_tail_flags;
+};
+
+static void *read_bitmaps_thread(void *data)
+{
+ struct read_bitmaps_thread_info *rbt = data;
+
+ rbt->rbt_retval = read_bitmaps_range_start(rbt->rbt_fs, rbt->rbt_flags,
+ rbt->rbt_grp_start, rbt->rbt_grp_end,
+ rbt->rbt_mutex, &rbt->rbt_tail_flags);
+ return NULL;
+}
+#endif
+
+errcode_t ext2fs_rw_bitmaps(ext2_filsys fs, int flags, int num_threads)
+{
+#ifdef HAVE_PTHREAD
+ pthread_attr_t attr;
+ pthread_t *thread_ids = NULL;
+ struct read_bitmaps_thread_info *thread_infos = NULL;
+ pthread_mutex_t rbt_mutex = PTHREAD_MUTEX_INITIALIZER;
+ errcode_t retval;
+ errcode_t rc;
+ unsigned flexbg_size = 1U << fs->super->s_log_groups_per_flex;
+ dgrp_t average_group;
+ int i, tail_flags = 0;
+#endif
+
+ if (flags & ~EXT2FS_BITMAPS_VALID_FLAGS)
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ if (ext2fs_has_feature_journal_dev(fs->super))
+ return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP;
+
+ if (flags & EXT2FS_BITMAPS_WRITE)
+ return write_bitmaps(fs, flags & EXT2FS_BITMAPS_INODE,
+ flags & EXT2FS_BITMAPS_BLOCK);
+
+#ifdef HAVE_PTHREAD
+ if (((fs->io->flags & CHANNEL_FLAGS_THREADS) == 0) ||
+ (num_threads == 1) || (fs->flags & EXT2_FLAG_IMAGE_FILE))
+ goto fallback;
+
+#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF)
+ if (num_threads < 0)
+ num_threads = sysconf(_SC_NPROCESSORS_CONF);
+#endif
+ /*
+ * Guess for now; eventually we should probably define
+ * ext2fs_get_num_cpus() and teach it how to get this info on
+ * MacOS, FreeBSD, etc.
+ * ref: https://stackoverflow.com/questions/150355
+ */
+ if (num_threads < 0)
+ num_threads = 4;
+
+ if ((unsigned) num_threads > fs->group_desc_count)
+ num_threads = fs->group_desc_count;
+ average_group = fs->group_desc_count / num_threads;
+ if (ext2fs_has_feature_flex_bg(fs->super)) {
+ average_group = (average_group / flexbg_size) * flexbg_size;
+ }
+ if ((num_threads <= 1) || (average_group == 0))
+ goto fallback;
+
+ io_channel_set_options(fs->io, "cache=off");
+ retval = pthread_attr_init(&attr);
+ if (retval)
+ return retval;
+
+ thread_ids = calloc(sizeof(pthread_t), num_threads);
+ if (!thread_ids)
+ return ENOMEM;
+
+ thread_infos = calloc(sizeof(struct read_bitmaps_thread_info),
+ num_threads);
+ if (!thread_infos)
+ goto out;
+
+ retval = read_bitmaps_range_prepare(fs, flags);
+ if (retval)
+ goto out;
+
+// fprintf(stdout, "Multiple threads triggered to read bitmaps\n");
+ for (i = 0; i < num_threads; i++) {
+ thread_infos[i].rbt_fs = fs;
+ thread_infos[i].rbt_flags = flags;
+ thread_infos[i].rbt_mutex = &rbt_mutex;
+ thread_infos[i].rbt_tail_flags = 0;
+ if (i == 0)
+ thread_infos[i].rbt_grp_start = 0;
+ else
+ thread_infos[i].rbt_grp_start = average_group * i + 1;
+
+ if (i == num_threads - 1)
+ thread_infos[i].rbt_grp_end = fs->group_desc_count - 1;
+ else
+ thread_infos[i].rbt_grp_end = average_group * (i + 1);
+ retval = pthread_create(&thread_ids[i], &attr,
+ &read_bitmaps_thread, &thread_infos[i]);
+ if (retval)
+ break;
+ }
+ for (i = 0; i < num_threads; i++) {
+ if (!thread_ids[i])
+ break;
+ rc = pthread_join(thread_ids[i], NULL);
+ if (rc && !retval)
+ retval = rc;
+ rc = thread_infos[i].rbt_retval;
+ if (rc && !retval)
+ retval = rc;
+ tail_flags |= thread_infos[i].rbt_tail_flags;
+ }
+out:
+ rc = pthread_attr_destroy(&attr);
+ if (rc && !retval)
+ retval = rc;
+ free(thread_infos);
+ free(thread_ids);
+
+ if (retval == 0)
+ retval = read_bitmaps_range_end(fs, flags, tail_flags);
+ if (retval)
+ read_bitmaps_cleanup_on_error(fs, flags);
+ /* XXX should save and restore cache setting */
+ io_channel_set_options(fs->io, "cache=on");
+ return retval;
+fallback:
+#endif /* HAVE_PTHREAD */
+ return read_bitmaps_range(fs, flags, 0, fs->group_desc_count - 1);
+}
+
+errcode_t ext2fs_read_inode_bitmap(ext2_filsys fs)
+{
+ return ext2fs_rw_bitmaps(fs, EXT2FS_BITMAPS_INODE, -1);
+}
+
+errcode_t ext2fs_read_block_bitmap(ext2_filsys fs)
+{
+ return ext2fs_rw_bitmaps(fs, EXT2FS_BITMAPS_BLOCK, -1);
+}
+
+errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
+{
+ return write_bitmaps(fs, 1, 0);
+}
+
+errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
+{
+ return write_bitmaps(fs, 0, 1);
+}
+
+errcode_t ext2fs_read_bitmaps(ext2_filsys fs)
+{
+ int flags = 0;
+
+ if (!fs->inode_map)
+ flags |= EXT2FS_BITMAPS_INODE;
+ if (!fs->block_map)
+ flags |= EXT2FS_BITMAPS_BLOCK;
+ if (flags == 0)
+ return 0;
+ return ext2fs_rw_bitmaps(fs, flags, -1);
+}
+
+errcode_t ext2fs_write_bitmaps(ext2_filsys fs)
+{
+ int do_inode = fs->inode_map && ext2fs_test_ib_dirty(fs);
+ int do_block = fs->block_map && ext2fs_test_bb_dirty(fs);
+
+ if (!do_inode && !do_block)
+ return 0;
+
+ return write_bitmaps(fs, do_inode, do_block);
+}