Adding upstream version 1.47.0.upstream/1.47.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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);
+}