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      1 /*	$NetBSD: ext2fs_extents.h,v 1.5 2023/08/26 05:22:50 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2012, 2010 Zheng Liu <lz (at) freebsd.org>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  *
     28  * $FreeBSD: head/sys/fs/ext2fs/ext2_extents.h 295523 2016-02-11 15:27:14Z pfg $
     29  */
     30 
     31 #ifndef _UFS_EXT2FS_EXT2FS_EXTENTS_H_
     32 #define	_UFS_EXT2FS_EXT2FS_EXTENTS_H_
     33 
     34 #include <sys/types.h>
     35 #ifndef _KERNEL
     36 #include <stdbool.h>
     37 #endif
     38 
     39 #include <ufs/ufs/inode.h>
     40 #define	EXT4_EXT_MAGIC  0xf30a
     41 
     42 #define	EXT4_EXT_CACHE_NO	0
     43 #define	EXT4_EXT_CACHE_GAP	1
     44 #define	EXT4_EXT_CACHE_IN	2
     45 
     46 /*
     47  * Ext4 file system extent on disk.
     48  */
     49 struct ext4_extent {
     50 	uint32_t e_blk;		/* first logical block */
     51 	uint16_t e_len;		/* number of blocks */
     52 	uint16_t e_start_hi;	/* high 16 bits of physical block */
     53 	uint32_t e_start_lo;	/* low 32 bits of physical block */
     54 };
     55 
     56 /*
     57  * Extent index on disk.
     58  */
     59 struct ext4_extent_index {
     60 	uint32_t ei_blk;	/* indexes logical blocks */
     61 	uint32_t ei_leaf_lo;	/* points to physical block of the
     62 				 * next level */
     63 	uint16_t ei_leaf_hi;	/* high 16 bits of physical block */
     64 	uint16_t ei_unused;
     65 };
     66 
     67 /*
     68  * Extent tree header.
     69  */
     70 struct ext4_extent_header {
     71 	uint16_t eh_magic;	/* magic number: 0xf30a */
     72 	uint16_t eh_ecount;	/* number of valid entries */
     73 	uint16_t eh_max;	/* capacity of store in entries */
     74 	uint16_t eh_depth;	/* the depth of extent tree */
     75 	uint32_t eh_gen;	/* generation of extent tree */
     76 };
     77 
     78 /*
     79  * Save cached extent.
     80  */
     81 struct ext4_extent_cache {
     82 	daddr_t	ec_start;	/* extent start */
     83 	uint32_t ec_blk;	/* logical block */
     84 	uint32_t ec_len;
     85 	uint32_t ec_type;
     86 };
     87 
     88 /*
     89  * Save path to some extent.
     90  */
     91 struct ext4_extent_path {
     92 	uint16_t ep_depth;
     93 	struct buf *ep_bp;
     94 	bool ep_is_sparse;
     95 	union {
     96 		struct ext4_extent ep_sparse_ext;
     97 		struct ext4_extent *ep_ext;
     98 	};
     99 	struct ext4_extent_index *ep_index;
    100 	struct ext4_extent_header *ep_header;
    101 };
    102 
    103 struct inode;
    104 struct m_ext2fs;
    105 
    106 int	ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
    107 void	ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
    108 struct ext4_extent_path *ext4_ext_find_extent(struct m_ext2fs *fs,
    109     struct inode *, daddr_t, struct ext4_extent_path *);
    110 
    111 #endif /* !_UFS_EXT2FS_EXT2FS_EXTENTS_H_ */
    112