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ext2fs_extents.h revision 1.1 
      1 /*	$NetBSD: ext2fs_extents.h,v 1.1 2016/06/03 15:35:48 christos 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 #include <ufs/ufs/inode.h>
     36 #define	EXT4_EXT_MAGIC  0xf30a
     37 
     38 #define	EXT4_EXT_CACHE_NO	0
     39 #define	EXT4_EXT_CACHE_GAP	1
     40 #define	EXT4_EXT_CACHE_IN	2
     41 
     42 /*
     43  * Ext4 file system extent on disk.
     44  */
     45 struct ext4_extent {
     46 	uint32_t e_blk;		/* first logical block */
     47 	uint16_t e_len;		/* number of blocks */
     48 	uint16_t e_start_hi;	/* high 16 bits of physical block */
     49 	uint32_t e_start_lo;	/* low 32 bits of physical block */
     50 };
     51 
     52 /*
     53  * Extent index on disk.
     54  */
     55 struct ext4_extent_index {
     56 	uint32_t ei_blk;	/* indexes logical blocks */
     57 	uint32_t ei_leaf_lo;	/* points to physical block of the
     58 				 * next level */
     59 	uint16_t ei_leaf_hi;	/* high 16 bits of physical block */
     60 	uint16_t ei_unused;
     61 };
     62 
     63 /*
     64  * Extent tree header.
     65  */
     66 struct ext4_extent_header {
     67 	uint16_t eh_magic;	/* magic number: 0xf30a */
     68 	uint16_t eh_ecount;	/* number of valid entries */
     69 	uint16_t eh_max;	/* capacity of store in entries */
     70 	uint16_t eh_depth;	/* the depth of extent tree */
     71 	uint32_t eh_gen;	/* generation of extent tree */
     72 };
     73 
     74 /*
     75  * Save cached extent.
     76  */
     77 struct ext4_extent_cache {
     78 	daddr_t	ec_start;	/* extent start */
     79 	uint32_t ec_blk;	/* logical block */
     80 	uint32_t ec_len;
     81 	uint32_t ec_type;
     82 };
     83 
     84 /*
     85  * Save path to some extent.
     86  */
     87 struct ext4_extent_path {
     88 	uint16_t ep_depth;
     89 	struct buf *ep_bp;
     90 	bool ep_is_sparse;
     91 	union {
     92 		struct ext4_extent ep_sparse_ext;
     93 		struct ext4_extent *ep_ext;
     94 	};
     95 	struct ext4_extent_index *ep_index;
     96 	struct ext4_extent_header *ep_header;
     97 };
     98 
     99 struct inode;
    100 struct m_ext2fs;
    101 
    102 int	ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
    103 void	ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
    104 struct ext4_extent_path *ext4_ext_find_extent(struct m_ext2fs *fs,
    105     struct inode *, daddr_t, struct ext4_extent_path *);
    106 
    107 #endif /* !_UFS_EXT2FS_EXT2FS_EXTENTS_H_ */
    108