/*
 * extent.c --- routines to implement extents support
 *
 * Copyright (C) 2007 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#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"
#include "ss/ss.h"

/*
 * Definitions to be dropped in lib/ext2fs/ext2fs.h
 */

/*
 * Private definitions
 */

struct extent_path {
	char		*buf;
	int		entries;
	int		max_entries;
	int		left;
	int		visit_num;
	int		flags;
	blk64_t		end_blk;
	void		*curr;
};


struct ext2_extent_handle {
	errcode_t		magic;
	ext2_filsys		fs;
	ext2_ino_t 		ino;
	struct ext2_inode	*inode;
	int			type;
	int			level;
	int			max_depth;
	struct extent_path	*path;
};

struct ext2_extent_path {
	errcode_t		magic;
	int			leaf_height;
	blk64_t			lblk;
};

/*
 *  Useful Debugging stuff
 */

#ifdef DEBUG
static void dbg_show_header(struct ext3_extent_header *eh)
{
	printf("header: magic=%x entries=%u max=%u depth=%u generation=%u\n",
	       eh->eh_magic, eh->eh_entries, eh->eh_max, eh->eh_depth,
	       eh->eh_generation);
}

static void dbg_show_index(struct ext3_extent_idx *ix)
{
	printf("index: block=%u leaf=%u leaf_hi=%u unused=%u\n",
	       ix->ei_block, ix->ei_leaf, ix->ei_leaf_hi, ix->ei_unused);
}

static void dbg_show_extent(struct ext3_extent *ex)
{
	printf("extent: block=%u-%u len=%u start=%u start_hi=%u\n",
	       ex->ee_block, ex->ee_block + ex->ee_len - 1,
	       ex->ee_len, ex->ee_start, ex->ee_start_hi);
}

static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
{
	if (desc)
		printf("%s: ", desc);
	printf("extent: lblk %llu--%llu, len %lu, pblk %llu, flags: ",
	       extent->e_lblk, extent->e_lblk + extent->e_len - 1,
	       extent->e_len, extent->e_pblk);
	if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
		fputs("LEAF ", stdout);
	if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
		fputs("UNINIT ", stdout);
	if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
		fputs("2ND_VISIT ", stdout);
	if (!extent->e_flags)
		fputs("(none)", stdout);
	fputc('\n', stdout);

}

#define dbg_printf(fmt, args...) printf(fmt, ## args)
#else
#define dbg_show_header(eh) do { } while (0)
#define dbg_show_index(ix) do { } while (0)
#define dbg_show_extent(ex) do { } while (0)
#define dbg_print_extent(desc, ex) do { } while (0)
#define dbg_printf(fmt, args...) do { } while (0)
#endif

/*
 * Verify the extent header as being sane
 */
errcode_t ext2fs_extent_header_verify(void *ptr, int size)
{
	int eh_max, entry_size;
	struct ext3_extent_header *eh = ptr;

	dbg_show_header(eh);
	if (ext2fs_le16_to_cpu(eh->eh_magic) != EXT3_EXT_MAGIC)
		return EXT2_ET_EXTENT_HEADER_BAD;
	if (ext2fs_le16_to_cpu(eh->eh_entries) > ext2fs_le16_to_cpu(eh->eh_max))
		return EXT2_ET_EXTENT_HEADER_BAD;
	if (eh->eh_depth == 0)
		entry_size = sizeof(struct ext3_extent);
	else
		entry_size = sizeof(struct ext3_extent_idx);

	eh_max = (size - sizeof(*eh)) / entry_size;
	/* Allow two extent-sized items at the end of the block, for
	 * ext4_extent_tail with checksum in the future. */
	if ((ext2fs_le16_to_cpu(eh->eh_max) > eh_max) || 
	    (ext2fs_le16_to_cpu(eh->eh_max) < (eh_max - 2)))
		return EXT2_ET_EXTENT_HEADER_BAD;

	return 0;
}


/*
 * Begin functions to handle an inode's extent information
 */

extern void ext2fs_extent_free(ext2_extent_handle_t handle)
{
	int			i;

	if (!handle)
		return;

	if (handle->inode)
		ext2fs_free_mem(&handle->inode);
	if (handle->path) {
		for (i=1; i < handle->max_depth; i++) {
			if (handle->path[i].buf)
				ext2fs_free_mem(&handle->path[i].buf);
		}
	}
	ext2fs_free_mem(&handle);
}

extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
				    ext2_extent_handle_t *ret_handle)
{
	struct ext2_extent_handle	*handle;
	errcode_t			retval;
	int				isize = EXT2_INODE_SIZE(fs->super);
	struct ext3_extent_header	*eh;
	struct ext3_extent_idx		*ix;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	if ((ino == 0) || (ino > fs->super->s_inodes_count))
		return EXT2_ET_BAD_INODE_NUM;

	retval = ext2fs_get_mem(sizeof(struct ext2_extent_handle), &handle);
	if (retval)
		return retval;
	memset(handle, 0, sizeof(struct ext2_extent_handle));

	retval = ext2fs_get_mem(isize, &handle->inode);
	if (retval)
		goto errout;

	handle->ino = ino;
	handle->fs = fs;

	retval = ext2fs_read_inode_full(fs, ino, handle->inode, isize);
	if (retval)
		goto errout;

	if (!(handle->inode->i_flags & EXT4_EXTENTS_FL))
		return EXT2_ET_INODE_NOT_EXTENT;

	eh = (struct ext3_extent_header *) &handle->inode->i_block;

	retval = ext2fs_extent_header_verify(eh, sizeof(handle->inode->i_block));
	if (retval)
		return (retval);

	handle->max_depth = ext2fs_le16_to_cpu(eh->eh_depth);
	handle->type = ext2fs_le16_to_cpu(eh->eh_magic);

	retval = ext2fs_get_mem(((handle->max_depth+1) *
				 sizeof(struct extent_path)),
				&handle->path);
	memset(handle->path, 0,
	       (handle->max_depth+1) * sizeof(struct extent_path));
	handle->path[0].buf = (char *) handle->inode->i_block;

	handle->path[0].left = handle->path[0].entries =
		ext2fs_le16_to_cpu(eh->eh_entries);
	handle->path[0].max_entries = ext2fs_le16_to_cpu(eh->eh_max);
	handle->path[0].curr = 0;
	handle->path[0].end_blk =
		((((__u64) handle->inode->i_size_high << 32) +
		  handle->inode->i_size + (fs->blocksize - 1))
		 >> EXT2_BLOCK_SIZE_BITS(fs->super));
	handle->path[0].visit_num = 1;
	handle->level = 0;
	handle->magic = EXT2_ET_MAGIC_EXTENT_HANDLE;

	*ret_handle = handle;
	return 0;

errout:
	ext2fs_extent_free(handle);
	return retval;
}

/*
 * This function is responsible for (optionally) moving through the
 * extent tree and then returning the current extent
 */
errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
			    int flags, struct ext2fs_extent *extent)
{
	struct extent_path	*path, *newpath;
	struct ext3_extent_header	*eh;
	struct ext3_extent_idx		*ix = 0;
	struct ext3_extent		*ex;
	errcode_t			retval;
	blk_t				blk;
	blk64_t				end_blk;
	int				orig_op, op;

	EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);

	if (!handle->path)
		return EXT2_ET_NO_CURRENT_NODE;

	orig_op = op = flags & EXT2_EXTENT_MOVE_MASK;

retry:
	path = handle->path + handle->level;
	if ((orig_op == EXT2_EXTENT_NEXT) ||
	    (orig_op == EXT2_EXTENT_NEXT_LEAF)) {
		if (handle->level < handle->max_depth) {
			/* interior node */
			if (path->visit_num == 0) {
				path->visit_num++;
				op = EXT2_EXTENT_DOWN;
			} else if (path->left > 0)
				op = EXT2_EXTENT_NEXT_SIB;
			else if (handle->level > 0)
				op = EXT2_EXTENT_UP;
			else
				return EXT2_ET_EXTENT_NO_NEXT;
		} else {
			/* leaf node */
			if (path->left > 0)
				op = EXT2_EXTENT_NEXT_SIB;
			else if (handle->level > 0)
				op = EXT2_EXTENT_UP;
			else
				return EXT2_ET_EXTENT_NO_NEXT;
		}
		if (op != EXT2_EXTENT_NEXT_SIB) {
			dbg_printf("<<<< OP = %s\n",
			       (op == EXT2_EXTENT_DOWN) ? "down" :
			       ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
		}
	}

	if ((orig_op == EXT2_EXTENT_PREV) ||
	    (orig_op == EXT2_EXTENT_PREV_LEAF)) {
		if (handle->level < handle->max_depth) {
			/* interior node */
			if (path->visit_num > 0 ) {
				/* path->visit_num = 0; */
				op = EXT2_EXTENT_DOWN_AND_LAST;
			} else if (path->left < path->entries-1)
				op = EXT2_EXTENT_PREV_SIB;
			else if (handle->level > 0)
				op = EXT2_EXTENT_UP;
			else
				return EXT2_ET_EXTENT_NO_PREV;
		} else {
			/* leaf node */
			if (path->left < path->entries-1)
				op = EXT2_EXTENT_PREV_SIB;
			else if (handle->level > 0)
				op = EXT2_EXTENT_UP;
			else
				return EXT2_ET_EXTENT_NO_PREV;
		}
		if (op != EXT2_EXTENT_PREV_SIB) {
			dbg_printf("<<<< OP = %s\n",
			       (op == EXT2_EXTENT_DOWN_AND_LAST) ? "down/last" :
			       ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
		}
	}

	if (orig_op == EXT2_EXTENT_LAST_LEAF) {
		if ((handle->level < handle->max_depth) &&
		    (path->left == 0))
			op = EXT2_EXTENT_DOWN;
		else
			op = EXT2_EXTENT_LAST_SIB;
		dbg_printf("<<<< OP = %s\n",
			   (op == EXT2_EXTENT_DOWN) ? "down" : "last_sib");
	}

	switch (op) {
	case EXT2_EXTENT_CURRENT:
		ix = path->curr;
		break;
	case EXT2_EXTENT_ROOT:
		handle->level = 0;
		path = handle->path + handle->level;
	case EXT2_EXTENT_FIRST_SIB:
		path->left = path->entries;
		path->curr = 0;
	case EXT2_EXTENT_NEXT_SIB:
		if (path->left <= 0)
			return EXT2_ET_EXTENT_NO_NEXT;
		if (path->curr) {
			ix = path->curr;
			ix++;
		} else {
			eh = (struct ext3_extent_header *) path->buf;
			ix = EXT_FIRST_INDEX(eh);
		}
		path->left--;
		path->curr = ix;
		path->visit_num = 0;
		break;
	case EXT2_EXTENT_PREV_SIB:
		if (!path->curr ||
		    path->left+1 >= path->entries)
			return EXT2_ET_EXTENT_NO_PREV;
		ix = path->curr;
		ix--;
		path->curr = ix;
		path->left++;
		if (handle->level < handle->max_depth)
			path->visit_num = 1;
		break;
	case EXT2_EXTENT_LAST_SIB:
		eh = (struct ext3_extent_header *) path->buf;
		path->curr = EXT_LAST_EXTENT(eh);
		ix = path->curr;
		path->left = 0;
		path->visit_num = 0;
		break;
	case EXT2_EXTENT_UP:
		if (handle->level <= 0)
			return EXT2_ET_EXTENT_NO_UP;
		handle->level--;
		path--;
		ix = path->curr;
		if ((orig_op == EXT2_EXTENT_PREV) ||
		    (orig_op == EXT2_EXTENT_PREV_LEAF))
			path->visit_num = 0;
		break;
	case EXT2_EXTENT_DOWN:
	case EXT2_EXTENT_DOWN_AND_LAST:
		if (!path->curr ||(handle->level >= handle->max_depth))
			return EXT2_ET_EXTENT_NO_DOWN;

		ix = path->curr;
		newpath = path + 1;
		if (!newpath->buf) {
			retval = ext2fs_get_mem(handle->fs->blocksize,
						&newpath->buf);
			if (retval)
				return retval;
		}
		blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
			((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi));
		if ((handle->fs->flags & EXT2_FLAG_IMAGE_FILE) &&
		    (handle->fs->io != handle->fs->image_io))
			memset(newpath->buf, 0, handle->fs->blocksize);
		else {
			retval = io_channel_read_blk(handle->fs->io,
						     blk, 1, newpath->buf);
			if (retval)
				return retval;
		}
		handle->level++;

		eh = (struct ext3_extent_header *) newpath->buf;

		retval = ext2fs_extent_header_verify(eh, handle->fs->blocksize);
		if (retval)
			return retval;

		newpath->left = newpath->entries =
			ext2fs_le16_to_cpu(eh->eh_entries);
		newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);

		if (path->left > 0) {
			ix++;
			newpath->end_blk = ext2fs_le32_to_cpu(ix->ei_block);
		} else
			newpath->end_blk = path->end_blk;

		path = newpath;
		if (op == EXT2_EXTENT_DOWN) {
			ix = EXT_FIRST_INDEX((struct ext3_extent_header *) eh);
			path->curr = ix;
			path->left = path->entries - 1;
			path->visit_num = 0;
		} else {
			ix = EXT_LAST_INDEX((struct ext3_extent_header *) eh);
			path->curr = ix;
			path->left = 0;
			if (handle->level < handle->max_depth)
				path->visit_num = 1;
		}

		dbg_printf("Down to level %d/%d, end_blk=%llu\n",
			   handle->level, handle->max_depth,
			   path->end_blk);

		break;
	default:
		return EXT2_ET_OP_NOT_SUPPORTED;
	}

	if (!ix)
		return EXT2_ET_NO_CURRENT_NODE;

	extent->e_flags = 0;

	if (handle->level == handle->max_depth) {
		ex = (struct ext3_extent *) ix;

		extent->e_pblk = ext2fs_le32_to_cpu(ex->ee_start) +
			((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
		extent->e_lblk = ext2fs_le32_to_cpu(ex->ee_block);
		extent->e_len = ext2fs_le16_to_cpu(ex->ee_len);
		extent->e_flags = EXT2_EXTENT_FLAGS_LEAF;
		if (extent->e_len > EXT_INIT_MAX_LEN) {
			extent->e_len -= EXT_INIT_MAX_LEN;
			extent->e_flags = EXT2_EXTENT_FLAGS_UNINIT;
		}
	} else {
		extent->e_pblk = ext2fs_le32_to_cpu(ix->ei_leaf) +
			((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
		extent->e_lblk = ext2fs_le32_to_cpu(ix->ei_block);
		if (path->left > 0) {
			ix++;
			end_blk = ext2fs_le32_to_cpu(ix->ei_block);
		} else
			end_blk = path->end_blk;

		extent->e_len = end_blk - extent->e_lblk;
	}
	if (path->visit_num)
		extent->e_flags |= EXT2_EXTENT_FLAGS_SECOND_VISIT;

	if (((orig_op == EXT2_EXTENT_NEXT_LEAF) ||
	     (orig_op == EXT2_EXTENT_PREV_LEAF)) &&
	    (handle->level != handle->max_depth))
		goto retry;

	if ((orig_op == EXT2_EXTENT_LAST_LEAF) &&
	    ((handle->level != handle->max_depth) ||
	     (path->left != 0)))
		goto retry;

	return 0;
}

static errcode_t update_path(ext2_extent_handle_t handle)
{
	struct extent_path		*path;
	blk64_t				blk;
	errcode_t			retval;
	struct ext3_extent_idx		*ix;

	if (handle->level == 0) {
		retval = ext2fs_write_inode_full(handle->fs, handle->ino,
			   handle->inode, EXT2_INODE_SIZE(handle->fs->super));
	} else {
		ix = handle->path[handle->level - 1].curr;
		blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
			((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);

		retval = io_channel_write_blk(handle->fs->io,
				      blk, 1, handle->path[handle->level].buf);
	}
	return retval;
}

errcode_t ext2fs_extent_save_path(ext2_extent_handle_t handle,
				  ext2_extent_path_t *ret_path)
{
	ext2_extent_path_t	save_path;
	struct ext2fs_extent	extent;
	struct ext2_extent_info	info;
	errcode_t		retval;

	retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
	if (retval)
		return retval;

	retval = ext2fs_extent_get_info(handle, &info);
	if (retval)
		return retval;

	retval = ext2fs_get_mem(sizeof(struct ext2_extent_path), &save_path);
	if (retval)
		return retval;
	memset(save_path, 0, sizeof(struct ext2_extent_path));

	save_path->magic = EXT2_ET_MAGIC_EXTENT_PATH;
	save_path->leaf_height = info.max_depth - info.curr_level - 1;
	save_path->lblk = extent.e_lblk;

	*ret_path = save_path;
	return 0;
}

errcode_t ext2fs_extent_free_path(ext2_extent_path_t path)
{
	EXT2_CHECK_MAGIC(path, EXT2_ET_MAGIC_EXTENT_PATH);

	ext2fs_free_mem(&path);
	return 0;
}

static errcode_t extent_goto(ext2_extent_handle_t handle,
			     int leaf_level, blk64_t blk)
{
	struct ext2fs_extent	extent, next;
	errcode_t		retval;

	retval = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
	if (retval)
		return retval;

	dbg_print_extent("root", &extent);
	while (1) {
		if (handle->level - leaf_level == handle->max_depth) {
			if ((blk >= extent.e_lblk) &&
			    (blk < extent.e_lblk + extent.e_len))
				return 0;
			if (blk < extent.e_lblk)
				return EXT2_ET_EXTENT_NOT_FOUND;
			retval = ext2fs_extent_get(handle,
						   EXT2_EXTENT_NEXT_SIB,
						   &extent);
			if (retval == EXT2_ET_EXTENT_NO_NEXT)
				return EXT2_ET_EXTENT_NOT_FOUND;
			if (retval)
				return retval;
			continue;
		}

		retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_SIB,
					   &extent);
		if (retval == EXT2_ET_EXTENT_NO_NEXT)
			goto go_down;
		if (retval)
			return retval;

		dbg_print_extent("next", &extent);
		if (blk == extent.e_lblk)
			goto go_down;
		if (blk > extent.e_lblk)
			continue;

		retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_SIB,
					   &extent);
		if (retval)
			return retval;

		dbg_print_extent("prev", &extent);

	go_down:
		retval = ext2fs_extent_get(handle, EXT2_EXTENT_DOWN,
					   &extent);
		if (retval)
			return retval;

		dbg_print_extent("down", &extent);
	}
}

errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
			     blk64_t blk)
{
	return extent_goto(handle, 0, blk);
}

errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
				struct ext2fs_extent *extent)
{
	struct extent_path		*path;
	struct ext3_extent_idx		*ix;
	struct ext3_extent		*ex;

	EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);

	if (!(handle->fs->flags & EXT2_FLAG_RW))
		return EXT2_ET_RO_FILSYS;

	if (!handle->path)
		return EXT2_ET_NO_CURRENT_NODE;

	path = handle->path + handle->level;
	if (!path->curr)
		return EXT2_ET_NO_CURRENT_NODE;

	if (handle->level == handle->max_depth) {
		ex = path->curr;

		ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
		ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
		ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
		ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
	} else {
		ix = path->curr;

		ix->ei_leaf = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
		ix->ei_leaf_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
		ix->ei_block = ext2fs_cpu_to_le32(extent->e_lblk);
		ix->ei_unused = 0;
	}
	update_path(handle);
	return 0;
}

errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
				      struct ext2fs_extent *extent)
{
	struct extent_path		*path;
	struct ext3_extent_idx		*ix;
	struct ext3_extent_header	*eh;
	errcode_t			retval;

	EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);

	if (!(handle->fs->flags & EXT2_FLAG_RW))
		return EXT2_ET_RO_FILSYS;

	if (!handle->path)
		return EXT2_ET_NO_CURRENT_NODE;

	path = handle->path + handle->level;

	if (path->entries >= path->max_entries)
		return EXT2_ET_CANT_INSERT_EXTENT;

	eh = (struct ext3_extent_header *) path->buf;
	if (path->curr) {
		ix = path->curr;
		if (flags & EXT2_EXTENT_INSERT_AFTER) {
			ix++;
			path->left--;
		}
	} else
		ix = EXT_FIRST_INDEX(eh);

	path->curr = ix;

	if (path->left > 0)
		memmove(ix + 1, ix,
			path->left * sizeof(struct ext3_extent_idx));
	path->left++;
	path->entries++;

	eh = (struct ext3_extent_header *) path->buf;
	eh->eh_entries = ext2fs_cpu_to_le16(path->entries);

	retval = ext2fs_extent_replace(handle, 0, extent);
	if (retval)
		goto errout;

	retval = update_path(handle);
	if (retval)
		goto errout;

	return 0;

errout:
	ext2fs_extent_delete(handle, 0);
	return retval;
}

errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
{
	struct extent_path		*path;
	char 				*cp;
	struct ext3_extent_header	*eh;
	errcode_t			retval;

	EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);

	if (!(handle->fs->flags & EXT2_FLAG_RW))
		return EXT2_ET_RO_FILSYS;

	if (!handle->path)
		return EXT2_ET_NO_CURRENT_NODE;

	path = handle->path + handle->level;
	if (!path->curr)
		return EXT2_ET_NO_CURRENT_NODE;

	cp = path->curr;

	if (path->left) {
		memmove(cp, cp + sizeof(struct ext3_extent_idx),
			path->left * sizeof(struct ext3_extent_idx));
		path->left--;
	}
	path->entries--;
	if (path->entries == 0)
		path->curr = 0;

	eh = (struct ext3_extent_header *) path->buf;
	eh->eh_entries = ext2fs_cpu_to_le16(path->entries);

	retval = update_path(handle);

	return retval;
}

errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
				 struct ext2_extent_info *info)
{
	struct extent_path		*path;
	struct ext3_extent_idx		*ix;
	struct ext3_extent		*ex;

	EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);

	memset(info, 0, sizeof(struct ext2_extent_info));

	path = handle->path + handle->level;
	if (path) {
		if (path->curr)
			info->curr_entry = ((char *) path->curr - path->buf) /
				sizeof(struct ext3_extent_idx);
		else
			info->curr_entry = 0;
		info->num_entries = path->entries;
		info->max_entries = path->max_entries;
		info->bytes_avail = (path->max_entries - path->entries) *
			sizeof(struct ext3_extent);
	}

	info->curr_level = handle->level;
	info->max_depth = handle->max_depth;
	info->max_lblk = ((__u64) 1 << 32) - 1;
	info->max_pblk = ((__u64) 1 << 48) - 1;
	info->max_len = (1UL << 15);
	info->max_uninit_len = (1UL << 15) - 1;

	return 0;
}

#ifdef DEBUG

#include "debugfs.h"

/*
 * Hook in new commands into debugfs
 */
char *debug_prog_name = "tst_extents";
extern ss_request_table extent_cmds;
ss_request_table *extra_cmds = &extent_cmds;

ext2_ino_t	current_ino = 0;
ext2_extent_handle_t current_handle;

void do_inode(int argc, char *argv[])
{
	ext2_ino_t	inode;
	int		i;
	struct ext3_extent_header *eh;
	errcode_t retval;

	if (check_fs_open(argv[0]))
		return;

	if (argc == 1) {
		if (current_ino)
			printf("Current inode is %d\n", current_ino);
		else
			printf("No current inode\n");
		return;
	}

	if (common_inode_args_process(argc, argv, &inode, 0)) {
		return;
	}

	current_ino = 0;

	retval = ext2fs_extent_open(current_fs, inode, &current_handle);
	if (retval) {
		com_err(argv[1], retval, "while opening extent handle");
		return;
	}

	current_ino = inode;

	printf("Loaded inode %d\n", current_ino);

	return;
}

void generic_goto_node(char *cmd_name, int op)
{
	struct ext2fs_extent	extent;
	errcode_t		retval;

	if (check_fs_open(cmd_name))
		return;

	if (!current_handle) {
		com_err(cmd_name, 0, "Extent handle not open");
		return;
	}

	retval = ext2fs_extent_get(current_handle, op, &extent);
	if (retval) {
		com_err(cmd_name, retval, 0);
		return;
	}
	dbg_print_extent(0, &extent);
}

void do_current_node(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
}

void do_root_node(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
}

void do_last_leaf(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_LAST_LEAF);
}

void do_first_sib(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
}

void do_last_sib(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_LAST_SIB);
}

void do_next_sib(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
}

void do_prev_sib(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
}

void do_next_leaf(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_NEXT_LEAF);
}

void do_prev_leaf(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_PREV_LEAF);
}

void do_next(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_NEXT);
}

void do_prev(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_PREV);
}

void do_up(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_UP);
}

void do_down(int argc, char *argv[])
{
	generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
}

void do_delete_node(int argc, char *argv[])
{
	errcode_t	retval;
	int		err;

	if (check_fs_read_write(argv[0]))
		return;

	retval = ext2fs_extent_delete(current_handle, 0);
	if (retval) {
		com_err(argv[0], retval, 0);
		return;
	}
	do_current_node(argc, argv);
}

void do_replace_node(int argc, char *argv[])
{
	errcode_t	retval;
	struct ext2fs_extent extent;
	int err;

	if (check_fs_read_write(argv[0]))
		return;

	if (argc != 4) {
		fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", argv[0]);
		return;
	}

	extent.e_lblk = parse_ulong(argv[1], argv[0],
				    "logical block", &err);
	if (err)
		return;

	extent.e_len = parse_ulong(argv[2], argv[0],
				    "logical block", &err);
	if (err)
		return;

	extent.e_pblk = parse_ulong(argv[3], argv[0],
				    "logical block", &err);
	if (err)
		return;

	retval = ext2fs_extent_replace(current_handle, 0, &extent);
	if (retval) {
		com_err(argv[0], retval, 0);
		return;
	}
	do_current_node(argc, argv);
}

void do_insert_node(int argc, char *argv[])
{
	errcode_t	retval;
	struct ext2fs_extent extent;
	char *cmd;
	int err;
	int flags = 0;

	if (check_fs_read_write(argv[0]))
		return;

	cmd = argv[0];

	if (argc > 2 && !strcmp(argv[1], "--after")) {
		argc--;
		argv++;
		flags |= EXT2_EXTENT_INSERT_AFTER;
	}

	if (argc != 4) {
		fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", cmd);
		return;
	}

	extent.e_lblk = parse_ulong(argv[1], cmd,
				    "logical block", &err);
	if (err)
		return;

	extent.e_len = parse_ulong(argv[2], cmd,
				    "length", &err);
	if (err)
		return;

	extent.e_pblk = parse_ulong(argv[3], cmd,
				    "pysical block", &err);
	if (err)
		return;

	retval = ext2fs_extent_insert(current_handle, flags, &extent);
	if (retval) {
		com_err(cmd, retval, 0);
		return;
	}
	do_current_node(argc, argv);
}

void do_print_all(int argc, char **argv)
{
	struct ext2fs_extent	extent;
	errcode_t		retval;
	errcode_t		end_err = EXT2_ET_EXTENT_NO_NEXT;
	int			op = EXT2_EXTENT_NEXT;
	int			first_op = EXT2_EXTENT_ROOT;


	if (check_fs_open(argv[0]))
		return;

	if (!current_handle) {
		com_err(argv[0], 0, "Extent handle not open");
		return;
	}

	if (argc > 2) {
	print_usage:
		fprintf(stderr,
			"Usage: %s [--leaf-only|--reverse|--reverse-leaf]\n",
			argv[0]);
		return;
	}

	if (argc == 2) {
		if (!strcmp(argv[1], "--leaf-only"))
			op = EXT2_EXTENT_NEXT_LEAF;
		else if (!strcmp(argv[1], "--reverse")) {
			op = EXT2_EXTENT_PREV;
			first_op = EXT2_EXTENT_LAST_LEAF;
			end_err = EXT2_ET_EXTENT_NO_PREV;
		} else if (!strcmp(argv[1], "--reverse-leaf")) {
			op = EXT2_EXTENT_PREV_LEAF;
			first_op = EXT2_EXTENT_LAST_LEAF;
			end_err = EXT2_ET_EXTENT_NO_PREV;
		} else
			  goto print_usage;
	}

	retval = ext2fs_extent_get(current_handle, first_op, &extent);
	if (retval) {
		com_err(argv[0], retval, 0);
		return;
	}
	dbg_print_extent(0, &extent);

	while (1) {
		retval = ext2fs_extent_get(current_handle, op, &extent);
		if (retval == end_err)
			break;

		if (retval) {
			com_err(argv[0], retval, 0);
			return;
		}
		dbg_print_extent(0, &extent);
	}
}

void do_info(int argc, char **argv)
{
	struct ext2_extent_info	info;
	errcode_t		retval;

	if (check_fs_open(argv[0]))
		return;

	if (!current_handle) {
		com_err(argv[0], 0, "Extent handle not open");
		return;
	}

	retval = ext2fs_extent_get_info(current_handle, &info);
	if (retval) {
		com_err(argv[0], retval, 0);
		return;
	}

	printf("Current handle location: %d/%d (max: %d, bytes %d), level %d/%d\n",
	       info.curr_entry, info.num_entries, info.max_entries,
	       info.bytes_avail, info.curr_level, info.max_depth);
	printf("\tmax lblk: %llu, max pblk: %llu\n", info.max_lblk,
	       info.max_pblk);
	printf("\tmax_len: %u, max_uninit_len: %u\n", info.max_len,
	       info.max_uninit_len);
}

void do_goto_block(int argc, char **argv)
{
	struct ext2fs_extent	extent;
	errcode_t		retval;
	int			op = EXT2_EXTENT_NEXT_LEAF;
	blk_t			blk;

	if (check_fs_open(argv[0]))
		return;

	if (!current_handle) {
		com_err(argv[0], 0, "Extent handle not open");
		return;
	}

	if (argc != 2) {
		fprintf(stderr, "%s block\n", argv[0]);
		return;
	}

	if (strtoblk(argv[0], argv[1], &blk))
		return;

	retval = ext2fs_extent_goto(current_handle, (blk64_t) blk);
	if (retval) {
		com_err(argv[0], retval, "while trying to go to block %lu",
			blk);
		return;
	}

	generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
}
#endif