Adding upstream version 1.47.0.upstream/1.47.0

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

1 files changed, 1122 insertions, 0 deletions

diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c
new file mode 100644
index 0000000..957d5aa
--- /dev/null
+++ b/lib/ext2fs/inode.c
@@ -0,0 +1,1122 @@
+/*
+ * inode.c --- utility routines to read and write inodes
+ *
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997 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
+#if HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#include <time.h>
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fsP.h"
+#include "e2image.h"
+
+#define IBLOCK_STATUS_CSUMS_OK	1
+#define IBLOCK_STATUS_INSANE	2
+#define SCAN_BLOCK_STATUS(scan)	((scan)->temp_buffer + (scan)->inode_size)
+
+struct ext2_struct_inode_scan {
+	errcode_t		magic;
+	ext2_filsys		fs;
+	ext2_ino_t		current_inode;
+	blk64_t			current_block;
+	dgrp_t			current_group;
+	ext2_ino_t		inodes_left;
+	blk_t			blocks_left;
+	dgrp_t			groups_left;
+	blk_t			inode_buffer_blocks;
+	char *			inode_buffer;
+	int			inode_size;
+	char *			ptr;
+	int			bytes_left;
+	char			*temp_buffer;
+	errcode_t		(*done_group)(ext2_filsys fs,
+					      ext2_inode_scan scan,
+					      dgrp_t group,
+					      void * priv_data);
+	void *			done_group_data;
+	int			bad_block_ptr;
+	int			scan_flags;
+	int			reserved[6];
+};
+
+/*
+ * This routine flushes the icache, if it exists.
+ */
+errcode_t ext2fs_flush_icache(ext2_filsys fs)
+{
+	unsigned	i;
+
+	if (!fs->icache)
+		return 0;
+
+	for (i=0; i < fs->icache->cache_size; i++)
+		fs->icache->cache[i].ino = 0;
+
+	fs->icache->buffer_blk = 0;
+	return 0;
+}
+
+/*
+ * Free the inode cache structure
+ */
+void ext2fs_free_inode_cache(struct ext2_inode_cache *icache)
+{
+	unsigned i;
+
+	if (--icache->refcount)
+		return;
+	if (icache->buffer)
+		ext2fs_free_mem(&icache->buffer);
+	for (i = 0; i < icache->cache_size; i++)
+		ext2fs_free_mem(&icache->cache[i].inode);
+	if (icache->cache)
+		ext2fs_free_mem(&icache->cache);
+	icache->buffer_blk = 0;
+	ext2fs_free_mem(&icache);
+}
+
+errcode_t ext2fs_create_inode_cache(ext2_filsys fs, unsigned int cache_size)
+{
+	unsigned	i;
+	errcode_t	retval;
+
+	if (fs->icache)
+		return 0;
+	retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache);
+	if (retval)
+		return retval;
+
+	memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
+	retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer);
+	if (retval)
+		goto errout;
+
+	fs->icache->buffer_blk = 0;
+	fs->icache->cache_last = -1;
+	fs->icache->cache_size = cache_size;
+	fs->icache->refcount = 1;
+	retval = ext2fs_get_array(fs->icache->cache_size,
+				  sizeof(struct ext2_inode_cache_ent),
+				  &fs->icache->cache);
+	if (retval)
+		goto errout;
+
+	for (i = 0; i < fs->icache->cache_size; i++) {
+		retval = ext2fs_get_mem(EXT2_INODE_SIZE(fs->super),
+					&fs->icache->cache[i].inode);
+		if (retval)
+			goto errout;
+	}
+
+	ext2fs_flush_icache(fs);
+	return 0;
+errout:
+	ext2fs_free_inode_cache(fs->icache);
+	fs->icache = 0;
+	return retval;
+}
+
+errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
+				 ext2_inode_scan *ret_scan)
+{
+	ext2_inode_scan	scan;
+	errcode_t	retval;
+	errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);
+
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	if (ext2fs_has_feature_journal_dev(fs->super))
+		return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP;
+
+	if (fs->blocksize < 1024)
+		return EXT2_FILSYS_CORRUPTED; /* Should never happen */
+
+	/*
+	 * If fs->badblocks isn't set, then set it --- since the inode
+	 * scanning functions require it.
+	 */
+	if (fs->badblocks == 0) {
+		/*
+		 * Temporarily save fs->get_blocks and set it to zero,
+		 * for compatibility with old e2fsck's.
+		 */
+		save_get_blocks = fs->get_blocks;
+		fs->get_blocks = 0;
+		retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
+		if (retval && fs->badblocks) {
+			ext2fs_badblocks_list_free(fs->badblocks);
+			fs->badblocks = 0;
+		}
+		fs->get_blocks = save_get_blocks;
+	}
+
+	retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
+	if (retval)
+		return retval;
+	memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
+
+	scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
+	scan->fs = fs;
+	scan->inode_size = EXT2_INODE_SIZE(fs->super);
+	scan->bytes_left = 0;
+	scan->current_group = 0;
+	scan->groups_left = fs->group_desc_count - 1;
+	scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks :
+				    EXT2_INODE_SCAN_DEFAULT_BUFFER_BLOCKS;
+	scan->current_block = ext2fs_inode_table_loc(scan->fs,
+						     scan->current_group);
+	if (scan->current_block &&
+	    ((scan->current_block < fs->super->s_first_data_block) ||
+	     (scan->current_block + fs->inode_blocks_per_group - 1 >=
+	      ext2fs_blocks_count(fs->super)))) {
+		ext2fs_free_mem(&scan);
+		return EXT2_ET_GDESC_BAD_INODE_TABLE;
+	}
+
+	scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
+	scan->blocks_left = scan->fs->inode_blocks_per_group;
+	if (ext2fs_has_group_desc_csum(fs)) {
+		__u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
+		if (scan->inodes_left > unused)
+			scan->inodes_left -= unused;
+		else
+			scan->inodes_left = 0;
+		scan->blocks_left =
+			(scan->inodes_left +
+			 (fs->blocksize / scan->inode_size - 1)) *
+			scan->inode_size / fs->blocksize;
+	}
+	retval = io_channel_alloc_buf(fs->io, scan->inode_buffer_blocks,
+				      &scan->inode_buffer);
+	scan->done_group = 0;
+	scan->done_group_data = 0;
+	scan->bad_block_ptr = 0;
+	if (retval) {
+		ext2fs_free_mem(&scan);
+		return retval;
+	}
+	retval = ext2fs_get_mem(scan->inode_size + scan->inode_buffer_blocks,
+				&scan->temp_buffer);
+	if (retval) {
+		ext2fs_free_mem(&scan->inode_buffer);
+		ext2fs_free_mem(&scan);
+		return retval;
+	}
+	memset(SCAN_BLOCK_STATUS(scan), 0, scan->inode_buffer_blocks);
+	if (scan->fs->badblocks && scan->fs->badblocks->num)
+		scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
+	if (ext2fs_has_group_desc_csum(fs))
+		scan->scan_flags |= EXT2_SF_DO_LAZY;
+	*ret_scan = scan;
+	return 0;
+}
+
+void ext2fs_close_inode_scan(ext2_inode_scan scan)
+{
+	if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
+		return;
+
+	ext2fs_free_mem(&scan->inode_buffer);
+	scan->inode_buffer = NULL;
+	ext2fs_free_mem(&scan->temp_buffer);
+	scan->temp_buffer = NULL;
+	ext2fs_free_mem(&scan);
+	return;
+}
+
+void ext2fs_set_inode_callback(ext2_inode_scan scan,
+			       errcode_t (*done_group)(ext2_filsys fs,
+						       ext2_inode_scan scan,
+						       dgrp_t group,
+						       void * priv_data),
+			       void *done_group_data)
+{
+	if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
+		return;
+
+	scan->done_group = done_group;
+	scan->done_group_data = done_group_data;
+}
+
+int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
+			    int clear_flags)
+{
+	int	old_flags;
+
+	if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
+		return 0;
+
+	old_flags = scan->scan_flags;
+	scan->scan_flags &= ~clear_flags;
+	scan->scan_flags |= set_flags;
+	return old_flags;
+}
+
+/*
+ * This function is called by ext2fs_get_next_inode when it needs to
+ * get ready to read in a new blockgroup.
+ */
+static errcode_t get_next_blockgroup(ext2_inode_scan scan)
+{
+	ext2_filsys fs = scan->fs;
+
+	scan->current_group++;
+	scan->groups_left--;
+
+	scan->current_block = ext2fs_inode_table_loc(scan->fs,
+						     scan->current_group);
+	scan->current_inode = scan->current_group *
+		EXT2_INODES_PER_GROUP(fs->super);
+
+	scan->bytes_left = 0;
+	scan->inodes_left = EXT2_INODES_PER_GROUP(fs->super);
+	scan->blocks_left = fs->inode_blocks_per_group;
+	if (ext2fs_has_group_desc_csum(fs)) {
+		__u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
+		if (scan->inodes_left > unused)
+			scan->inodes_left -= unused;
+		else
+			scan->inodes_left = 0;
+		scan->blocks_left =
+			(scan->inodes_left +
+			 (fs->blocksize / scan->inode_size - 1)) *
+			scan->inode_size / fs->blocksize;
+	}
+	if (scan->current_block &&
+	    ((scan->current_block < fs->super->s_first_data_block) ||
+	     (scan->current_block + fs->inode_blocks_per_group - 1 >=
+	      ext2fs_blocks_count(fs->super))))
+		return EXT2_ET_GDESC_BAD_INODE_TABLE;
+	return 0;
+}
+
+errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
+					    int	group)
+{
+	scan->current_group = group - 1;
+	scan->groups_left = scan->fs->group_desc_count - group;
+	scan->bad_block_ptr = 0;
+	return get_next_blockgroup(scan);
+}
+
+/*
+ * This function is called by get_next_blocks() to check for bad
+ * blocks in the inode table.
+ *
+ * This function assumes that badblocks_list->list is sorted in
+ * increasing order.
+ */
+static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
+					    blk64_t *num_blocks)
+{
+	blk64_t	blk = scan->current_block;
+	badblocks_list	bb = scan->fs->badblocks;
+
+	/*
+	 * If the inode table is missing, then obviously there are no
+	 * bad blocks.  :-)
+	 */
+	if (blk == 0)
+		return 0;
+
+	/* Make sure bad_block_ptr is still valid */
+	if (scan->bad_block_ptr >= bb->num) {
+		scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
+		return 0;
+	}
+
+	/*
+	 * If the current block is greater than the bad block listed
+	 * in the bad block list, then advance the pointer until this
+	 * is no longer the case.  If we run out of bad blocks, then
+	 * we don't need to do any more checking!
+	 */
+	while (blk > bb->list[scan->bad_block_ptr]) {
+		if (++scan->bad_block_ptr >= bb->num) {
+			scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
+			return 0;
+		}
+	}
+
+	/*
+	 * If the current block is equal to the bad block listed in
+	 * the bad block list, then handle that one block specially.
+	 * (We could try to handle runs of bad blocks, but that
+	 * only increases CPU efficiency by a small amount, at the
+	 * expense of a huge expense of code complexity, and for an
+	 * uncommon case at that.)
+	 */
+	if (blk == bb->list[scan->bad_block_ptr]) {
+		scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
+		*num_blocks = 1;
+		if (++scan->bad_block_ptr >= bb->num)
+			scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
+		return 0;
+	}
+
+	/*
+	 * If there is a bad block in the range that we're about to
+	 * read in, adjust the number of blocks to read so that we we
+	 * don't read in the bad block.  (Then the next block to read
+	 * will be the bad block, which is handled in the above case.)
+	 */
+	if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
+		*num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
+
+	return 0;
+}
+
+static int block_map_looks_insane(ext2_filsys fs,
+				  struct ext2_inode_large *inode)
+{
+	unsigned int i, bad;
+
+	/* We're only interested in block mapped files, dirs, and symlinks */
+	if ((inode->i_flags & EXT4_INLINE_DATA_FL) ||
+	    (inode->i_flags & EXT4_EXTENTS_FL))
+		return 0;
+	if (!LINUX_S_ISREG(inode->i_mode) &&
+	    !LINUX_S_ISLNK(inode->i_mode) &&
+	    !LINUX_S_ISDIR(inode->i_mode))
+		return 0;
+	if (LINUX_S_ISLNK(inode->i_mode) &&
+	    EXT2_I_SIZE(inode) <= sizeof(inode->i_block))
+		return 0;
+
+	/* Unused inodes probably aren't insane */
+	if (inode->i_links_count == 0)
+		return 0;
+
+	/* See if more than half the block maps are insane */
+	for (i = 0, bad = 0; i < EXT2_N_BLOCKS; i++)
+		if (inode->i_block[i] != 0 &&
+		    (inode->i_block[i] < fs->super->s_first_data_block ||
+		     inode->i_block[i] >= ext2fs_blocks_count(fs->super)))
+			bad++;
+	return bad > EXT2_N_BLOCKS / 2;
+}
+
+static int extent_head_looks_insane(struct ext2_inode_large *inode)
+{
+	if (!(inode->i_flags & EXT4_EXTENTS_FL) ||
+	    ext2fs_extent_header_verify(inode->i_block,
+					sizeof(inode->i_block)) == 0)
+		return 0;
+	return 1;
+}
+
+/*
+ * Check all the inodes that we just read into the buffer.  Record what we
+ * find here -- currently, we can observe that all checksums are ok; more
+ * than half the inodes are insane; or no conclusions at all.
+ */
+static void check_inode_block_sanity(ext2_inode_scan scan, blk64_t num_blocks)
+{
+	ext2_ino_t	ino, inodes_to_scan;
+	unsigned int	badness, checksum_failures;
+	unsigned int	inodes_in_buf, inodes_per_block;
+	char		*p;
+	struct ext2_inode_large *inode;
+	char		*block_status;
+	unsigned int	blk, bad_csum;
+
+	if (!(scan->scan_flags & EXT2_SF_WARN_GARBAGE_INODES))
+		return;
+
+	inodes_to_scan = scan->inodes_left;
+	inodes_in_buf = num_blocks * scan->fs->blocksize / scan->inode_size;
+	if (inodes_to_scan > inodes_in_buf)
+		inodes_to_scan = inodes_in_buf;
+
+	p = (char *) scan->inode_buffer;
+	ino = scan->current_inode + 1;
+	checksum_failures = badness = 0;
+	block_status = SCAN_BLOCK_STATUS(scan);
+	memset(block_status, 0, scan->inode_buffer_blocks);
+	inodes_per_block = EXT2_INODES_PER_BLOCK(scan->fs->super);
+
+	if (inodes_per_block < 2)
+		return;
+
+#ifdef WORDS_BIGENDIAN
+	if (ext2fs_get_mem(EXT2_INODE_SIZE(scan->fs->super), &inode))
+		return;
+#endif
+
+	while (inodes_to_scan > 0) {
+		blk = (p - (char *)scan->inode_buffer) / scan->fs->blocksize;
+		bad_csum = ext2fs_inode_csum_verify(scan->fs, ino,
+				(struct ext2_inode_large *) p) == 0;
+
+#ifdef WORDS_BIGENDIAN
+		ext2fs_swap_inode_full(scan->fs,
+			       (struct ext2_inode_large *) inode,
+			       (struct ext2_inode_large *) p,
+			       0, EXT2_INODE_SIZE(scan->fs->super));
+#else
+		inode = (struct ext2_inode_large *) p;
+#endif
+
+		/* Is this inode insane? */
+		if (bad_csum) {
+			checksum_failures++;
+			badness++;
+		} else if (extent_head_looks_insane(inode) ||
+			   block_map_looks_insane(scan->fs, inode))
+			badness++;
+
+		/* If more than half are insane, declare the whole block bad */
+		if (badness > inodes_per_block / 2) {
+			unsigned int ino_adj;
+
+			block_status[blk] |= IBLOCK_STATUS_INSANE;
+			ino_adj = inodes_per_block -
+						((ino - 1) % inodes_per_block);
+			if (ino_adj > inodes_to_scan)
+				ino_adj = inodes_to_scan;
+			inodes_to_scan -= ino_adj;
+			p += scan->inode_size * ino_adj;
+			ino += ino_adj;
+			checksum_failures = badness = 0;
+			continue;
+		}
+
+		if ((ino % inodes_per_block) == 0) {
+			if (checksum_failures == 0)
+				block_status[blk] |= IBLOCK_STATUS_CSUMS_OK;
+			checksum_failures = badness = 0;
+		}
+		inodes_to_scan--;
+		p += scan->inode_size;
+		ino++;
+	};
+
+#ifdef WORDS_BIGENDIAN
+	ext2fs_free_mem(&inode);
+#endif
+}
+
+/*
+ * This function is called by ext2fs_get_next_inode when it needs to
+ * read in more blocks from the current blockgroup's inode table.
+ */
+static errcode_t get_next_blocks(ext2_inode_scan scan)
+{
+	blk64_t		num_blocks;
+	errcode_t	retval;
+
+	/*
+	 * Figure out how many blocks to read; we read at most
+	 * inode_buffer_blocks, and perhaps less if there aren't that
+	 * many blocks left to read.
+	 */
+	num_blocks = scan->inode_buffer_blocks;
+	if (num_blocks > scan->blocks_left)
+		num_blocks = scan->blocks_left;
+
+	/*
+	 * If the past block "read" was a bad block, then mark the
+	 * left-over extra bytes as also being bad.
+	 */
+	if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
+		if (scan->bytes_left)
+			scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
+		scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
+	}
+
+	/*
+	 * Do inode bad block processing, if necessary.
+	 */
+	if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
+		retval = check_for_inode_bad_blocks(scan, &num_blocks);
+		if (retval)
+			return retval;
+	}
+
+	if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
+	    (scan->current_block == 0)) {
+		memset(scan->inode_buffer, 0,
+		       (size_t) num_blocks * scan->fs->blocksize);
+	} else {
+		retval = io_channel_read_blk64(scan->fs->io,
+					     scan->current_block,
+					     (int) num_blocks,
+					     scan->inode_buffer);
+		if (retval)
+			return EXT2_ET_NEXT_INODE_READ;
+	}
+	check_inode_block_sanity(scan, num_blocks);
+
+	scan->ptr = scan->inode_buffer;
+	scan->bytes_left = num_blocks * scan->fs->blocksize;
+
+	scan->blocks_left -= num_blocks;
+	if (scan->current_block)
+		scan->current_block += num_blocks;
+
+	return 0;
+}
+
+#if 0
+/*
+ * Returns 1 if the entire inode_buffer has a non-zero size and
+ * contains all zeros.  (Not just deleted inodes, since that means
+ * that part of the inode table was used at one point; we want all
+ * zeros, which means that the inode table is pristine.)
+ */
+static inline int is_empty_scan(ext2_inode_scan scan)
+{
+	int	i;
+
+	if (scan->bytes_left == 0)
+		return 0;
+
+	for (i=0; i < scan->bytes_left; i++)
+		if (scan->ptr[i])
+			return 0;
+	return 1;
+}
+#endif
+
+errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
+				     struct ext2_inode *inode, int bufsize)
+{
+	errcode_t	retval;
+	int		extra_bytes = 0;
+	int		length;
+	struct ext2_inode_large	*iptr = (struct ext2_inode_large *)inode;
+	char		*iblock_status;
+	unsigned int	iblk;
+
+	EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
+	length = EXT2_INODE_SIZE(scan->fs->super);
+	iblock_status = SCAN_BLOCK_STATUS(scan);
+
+	/*
+	 * Do we need to start reading a new block group?
+	 */
+	if (scan->inodes_left <= 0) {
+	force_new_group:
+		if (scan->done_group) {
+			retval = (scan->done_group)
+				(scan->fs, scan, scan->current_group,
+				 scan->done_group_data);
+			if (retval)
+				return retval;
+		}
+		if (scan->groups_left <= 0) {
+			*ino = 0;
+			return 0;
+		}
+		retval = get_next_blockgroup(scan);
+		if (retval)
+			return retval;
+	}
+	/*
+	 * These checks are done outside the above if statement so
+	 * they can be done for block group #0.
+	 */
+	if ((scan->scan_flags & EXT2_SF_DO_LAZY) &&
+	    (ext2fs_bg_flags_test(scan->fs, scan->current_group, EXT2_BG_INODE_UNINIT)
+	     ))
+		goto force_new_group;
+	if (scan->inodes_left == 0)
+		goto force_new_group;
+	if (scan->current_block == 0) {
+		if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
+			goto force_new_group;
+		} else
+			return EXT2_ET_MISSING_INODE_TABLE;
+	}
+
+
+	/*
+	 * Have we run out of space in the inode buffer?  If so, we
+	 * need to read in more blocks.
+	 */
+	if (scan->bytes_left < scan->inode_size) {
+		if (scan->bytes_left)
+			memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
+		extra_bytes = scan->bytes_left;
+
+		retval = get_next_blocks(scan);
+		if (retval)
+			return retval;
+#if 0
+		/*
+		 * XXX test  Need check for used inode somehow.
+		 * (Note: this is hard.)
+		 */
+		if (is_empty_scan(scan))
+			goto force_new_group;
+#endif
+	}
+
+	if (bufsize < length) {
+		retval = ext2fs_get_mem(length, &iptr);
+		if (retval)
+			return retval;
+	}
+
+	retval = 0;
+	iblk = scan->current_inode % EXT2_INODES_PER_GROUP(scan->fs->super) /
+				EXT2_INODES_PER_BLOCK(scan->fs->super) %
+				scan->inode_buffer_blocks;
+	if (extra_bytes) {
+		memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
+		       scan->inode_size - extra_bytes);
+		scan->ptr += scan->inode_size - extra_bytes;
+		scan->bytes_left -= scan->inode_size - extra_bytes;
+
+		/* Verify the inode checksum. */
+		if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) &&
+		    !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+		    !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1,
+				(struct ext2_inode_large *)scan->temp_buffer))
+			retval = EXT2_ET_INODE_CSUM_INVALID;
+
+#ifdef WORDS_BIGENDIAN
+		memset(iptr, 0, length);
+		ext2fs_swap_inode_full(scan->fs,
+			       (struct ext2_inode_large *) iptr,
+			       (struct ext2_inode_large *) scan->temp_buffer,
+			       0, length);
+#else
+		memcpy(iptr, scan->temp_buffer, length);
+#endif
+		if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
+			retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
+		scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
+	} else {
+		/* Verify the inode checksum. */
+		if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) &&
+		    !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+		    !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1,
+				(struct ext2_inode_large *)scan->ptr))
+			retval = EXT2_ET_INODE_CSUM_INVALID;
+
+#ifdef WORDS_BIGENDIAN
+		memset(iptr, 0, length);
+		ext2fs_swap_inode_full(scan->fs,
+				(struct ext2_inode_large *) iptr,
+				(struct ext2_inode_large *) scan->ptr,
+				0, length);
+#else
+		memcpy(iptr, scan->ptr, length);
+#endif
+		scan->ptr += scan->inode_size;
+		scan->bytes_left -= scan->inode_size;
+		if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
+			retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
+	}
+	if ((iblock_status[iblk] & IBLOCK_STATUS_INSANE) &&
+	    (retval == 0 || retval == EXT2_ET_INODE_CSUM_INVALID))
+		retval = EXT2_ET_INODE_IS_GARBAGE;
+
+	scan->inodes_left--;
+	scan->current_inode++;
+	*ino = scan->current_inode;
+	if (iptr != (struct ext2_inode_large *)inode) {
+		memcpy(inode, iptr, bufsize);
+		ext2fs_free_mem(&iptr);
+	}
+	return retval;
+}
+
+errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
+				struct ext2_inode *inode)
+{
+	return ext2fs_get_next_inode_full(scan, ino, inode,
+						sizeof(struct ext2_inode));
+}
+
+/*
+ * Functions to read and write a single inode.
+ */
+errcode_t ext2fs_read_inode2(ext2_filsys fs, ext2_ino_t ino,
+			     struct ext2_inode * inode, int bufsize,
+			     int flags)
+{
+	blk64_t		block_nr;
+	dgrp_t		group;
+	unsigned long 	block, offset;
+	char 		*ptr;
+	errcode_t	retval;
+	unsigned	i;
+	int		clen, inodes_per_block;
+	io_channel	io;
+	int		length = EXT2_INODE_SIZE(fs->super);
+	struct ext2_inode_large	*iptr;
+	int		cache_slot, fail_csum;
+
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	if (ext2fs_has_feature_journal_dev(fs->super))
+		return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP;
+
+	if (fs->blocksize < 1024)
+		return EXT2_FILSYS_CORRUPTED; /* Should never happen */
+
+	/* Check to see if user has an override function */
+	if (fs->read_inode &&
+	    ((bufsize == sizeof(struct ext2_inode)) ||
+	     (EXT2_INODE_SIZE(fs->super) == sizeof(struct ext2_inode)))) {
+		retval = (fs->read_inode)(fs, ino, inode);
+		if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
+			return retval;
+	}
+	if ((ino == 0) || (ino > fs->super->s_inodes_count))
+		return EXT2_ET_BAD_INODE_NUM;
+	/* Create inode cache if not present */
+	if (!fs->icache) {
+		retval = ext2fs_create_inode_cache(fs, 4);
+		if (retval)
+			return retval;
+	}
+	/* Check to see if it's in the inode cache */
+	for (i = 0; i < fs->icache->cache_size; i++) {
+		if (fs->icache->cache[i].ino == ino) {
+			memcpy(inode, fs->icache->cache[i].inode,
+			       (bufsize > length) ? length : bufsize);
+			return 0;
+		}
+	}
+	if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
+		inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
+		block_nr = ext2fs_le32_to_cpu(fs->image_header->offset_inode) / fs->blocksize;
+		block_nr += (ino - 1) / inodes_per_block;
+		offset = ((ino - 1) % inodes_per_block) *
+			EXT2_INODE_SIZE(fs->super);
+		io = fs->image_io;
+	} else {
+		group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
+		if (group > fs->group_desc_count)
+			return EXT2_ET_BAD_INODE_NUM;
+		offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
+			EXT2_INODE_SIZE(fs->super);
+		block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
+		block_nr = ext2fs_inode_table_loc(fs, group);
+		if (!block_nr)
+			return EXT2_ET_MISSING_INODE_TABLE;
+		if ((block_nr < fs->super->s_first_data_block) ||
+		    (block_nr + fs->inode_blocks_per_group - 1 >=
+		     ext2fs_blocks_count(fs->super)))
+			return EXT2_ET_GDESC_BAD_INODE_TABLE;
+		block_nr += block;
+		io = fs->io;
+	}
+	offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
+
+	cache_slot = (fs->icache->cache_last + 1) % fs->icache->cache_size;
+	iptr = (struct ext2_inode_large *)fs->icache->cache[cache_slot].inode;
+
+	ptr = (char *) iptr;
+	while (length) {
+		clen = length;
+		if ((offset + length) > fs->blocksize)
+			clen = fs->blocksize - offset;
+
+		if (block_nr != fs->icache->buffer_blk) {
+			retval = io_channel_read_blk64(io, block_nr, 1,
+						     fs->icache->buffer);
+			if (retval)
+				return retval;
+			fs->icache->buffer_blk = block_nr;
+		}
+
+		memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
+		       clen);
+
+		offset = 0;
+		length -= clen;
+		ptr += clen;
+		block_nr++;
+	}
+	length = EXT2_INODE_SIZE(fs->super);
+
+	/* Verify the inode checksum. */
+	fail_csum = !ext2fs_inode_csum_verify(fs, ino, iptr);
+
+#ifdef WORDS_BIGENDIAN
+	ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr,
+			       (struct ext2_inode_large *) iptr,
+			       0, length);
+#endif
+
+	/* Update the inode cache bookkeeping */
+	if (!fail_csum) {
+		fs->icache->cache_last = cache_slot;
+		fs->icache->cache[cache_slot].ino = ino;
+	}
+	memcpy(inode, iptr, (bufsize > length) ? length : bufsize);
+
+	if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+	    !(flags & READ_INODE_NOCSUM) && fail_csum)
+		return EXT2_ET_INODE_CSUM_INVALID;
+
+	return 0;
+}
+
+errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
+				 struct ext2_inode * inode, int bufsize)
+{
+	return ext2fs_read_inode2(fs, ino, inode, bufsize, 0);
+}
+
+errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
+			    struct ext2_inode * inode)
+{
+	return ext2fs_read_inode2(fs, ino, inode,
+				  sizeof(struct ext2_inode), 0);
+}
+
+errcode_t ext2fs_write_inode2(ext2_filsys fs, ext2_ino_t ino,
+			      struct ext2_inode * inode, int bufsize,
+			      int flags)
+{
+	blk64_t block_nr;
+	dgrp_t group;
+	unsigned long block, offset;
+	errcode_t retval = 0;
+	struct ext2_inode_large *w_inode;
+	char *ptr;
+	unsigned i;
+	int clen;
+	int length = EXT2_INODE_SIZE(fs->super);
+
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	if (ext2fs_has_feature_journal_dev(fs->super))
+		return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP;
+
+	/* Check to see if user provided an override function */
+	if (fs->write_inode) {
+		retval = (fs->write_inode)(fs, ino, inode);
+		if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
+			return retval;
+	}
+
+	if ((ino == 0) || (ino > fs->super->s_inodes_count))
+		return EXT2_ET_BAD_INODE_NUM;
+
+	/* Prepare our shadow buffer for read/modify/byteswap/write */
+	retval = ext2fs_get_mem(length, &w_inode);
+	if (retval)
+		return retval;
+
+	if (bufsize < length) {
+		retval = ext2fs_read_inode2(fs, ino,
+					    (struct ext2_inode *)w_inode,
+					    length, READ_INODE_NOCSUM);
+		if (retval)
+			goto errout;
+	}
+
+	/* Check to see if the inode cache needs to be updated */
+	if (fs->icache) {
+		for (i=0; i < fs->icache->cache_size; i++) {
+			if (fs->icache->cache[i].ino == ino) {
+				memcpy(fs->icache->cache[i].inode, inode,
+				       (bufsize > length) ? length : bufsize);
+				break;
+			}
+		}
+	} else {
+		retval = ext2fs_create_inode_cache(fs, 4);
+		if (retval)
+			goto errout;
+	}
+	memcpy(w_inode, inode, (bufsize > length) ? length : bufsize);
+
+	if (!(fs->flags & EXT2_FLAG_RW)) {
+		retval = EXT2_ET_RO_FILSYS;
+		goto errout;
+	}
+
+#ifdef WORDS_BIGENDIAN
+	ext2fs_swap_inode_full(fs, w_inode, w_inode, 1, length);
+#endif
+
+	if ((flags & WRITE_INODE_NOCSUM) == 0) {
+		retval = ext2fs_inode_csum_set(fs, ino, w_inode);
+		if (retval)
+			goto errout;
+	}
+
+	group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
+	offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
+		EXT2_INODE_SIZE(fs->super);
+	block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
+	block_nr = ext2fs_inode_table_loc(fs, (unsigned) group);
+	if (!block_nr) {
+		retval = EXT2_ET_MISSING_INODE_TABLE;
+		goto errout;
+	}
+	if ((block_nr < fs->super->s_first_data_block) ||
+	    (block_nr + fs->inode_blocks_per_group - 1 >=
+	     ext2fs_blocks_count(fs->super))) {
+		retval = EXT2_ET_GDESC_BAD_INODE_TABLE;
+		goto errout;
+	}
+	block_nr += block;
+
+	offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
+
+	ptr = (char *) w_inode;
+
+	while (length) {
+		clen = length;
+		if ((offset + length) > fs->blocksize)
+			clen = fs->blocksize - offset;
+
+		if (fs->icache->buffer_blk != block_nr) {
+			retval = io_channel_read_blk64(fs->io, block_nr, 1,
+						     fs->icache->buffer);
+			if (retval)
+				goto errout;
+			fs->icache->buffer_blk = block_nr;
+		}
+
+
+		memcpy((char *) fs->icache->buffer + (unsigned) offset,
+		       ptr, clen);
+
+		retval = io_channel_write_blk64(fs->io, block_nr, 1,
+					      fs->icache->buffer);
+		if (retval)
+			goto errout;
+
+		offset = 0;
+		ptr += clen;
+		length -= clen;
+		block_nr++;
+	}
+
+	fs->flags |= EXT2_FLAG_CHANGED;
+errout:
+	ext2fs_free_mem(&w_inode);
+	return retval;
+}
+
+errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
+				  struct ext2_inode * inode, int bufsize)
+{
+	return ext2fs_write_inode2(fs, ino, inode, bufsize, 0);
+}
+
+errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
+			     struct ext2_inode *inode)
+{
+	return ext2fs_write_inode2(fs, ino, inode,
+				   sizeof(struct ext2_inode), 0);
+}
+
+/*
+ * This function should be called when writing a new inode.  It makes
+ * sure that extra part of large inodes is initialized properly.
+ */
+errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
+				 struct ext2_inode *inode)
+{
+	struct ext2_inode	*buf;
+	int 			size = EXT2_INODE_SIZE(fs->super);
+	struct ext2_inode_large	*large_inode;
+	errcode_t		retval;
+	__u32 			t = fs->now ? fs->now : time(NULL);
+
+	if (!inode->i_ctime)
+		inode->i_ctime = t;
+	if (!inode->i_mtime)
+		inode->i_mtime = t;
+	if (!inode->i_atime)
+		inode->i_atime = t;
+
+	if (size == sizeof(struct ext2_inode))
+		return ext2fs_write_inode_full(fs, ino, inode,
+					       sizeof(struct ext2_inode));
+
+	buf = malloc(size);
+	if (!buf)
+		return ENOMEM;
+
+	memset(buf, 0, size);
+	*buf = *inode;
+
+	large_inode = (struct ext2_inode_large *) buf;
+	large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
+		EXT2_GOOD_OLD_INODE_SIZE;
+	if (!large_inode->i_crtime)
+		large_inode->i_crtime = t;
+
+	retval = ext2fs_write_inode_full(fs, ino, buf, size);
+	free(buf);
+	return retval;
+}
+
+
+errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
+{
+	struct ext2_inode	inode;
+	int			i;
+	errcode_t		retval;
+
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	if (ino > fs->super->s_inodes_count)
+		return EXT2_ET_BAD_INODE_NUM;
+
+	if (fs->get_blocks) {
+		if (!(*fs->get_blocks)(fs, ino, blocks))
+			return 0;
+	}
+	retval = ext2fs_read_inode(fs, ino, &inode);
+	if (retval)
+		return retval;
+	for (i=0; i < EXT2_N_BLOCKS; i++)
+		blocks[i] = inode.i_block[i];
+	return 0;
+}
+
+errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
+{
+	struct	ext2_inode	inode;
+	errcode_t		retval;
+
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	if (ino > fs->super->s_inodes_count)
+		return EXT2_ET_BAD_INODE_NUM;
+
+	if (fs->check_directory) {
+		retval = (fs->check_directory)(fs, ino);
+		if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
+			return retval;
+	}
+	retval = ext2fs_read_inode(fs, ino, &inode);
+	if (retval)
+		return retval;
+	if (!LINUX_S_ISDIR(inode.i_mode))
+		return EXT2_ET_NO_DIRECTORY;
+	return 0;
+}
+