xref: /OK3568_Linux_fs/u-boot/fs/zfs/zfs_lzjb.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  *  GRUB  --  GRand Unified Bootloader
3*4882a593Smuzhiyun  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
6*4882a593Smuzhiyun  */
7*4882a593Smuzhiyun /*
8*4882a593Smuzhiyun  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
9*4882a593Smuzhiyun  * Use is subject to license terms.
10*4882a593Smuzhiyun  */
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <common.h>
13*4882a593Smuzhiyun #include <malloc.h>
14*4882a593Smuzhiyun #include <linux/stat.h>
15*4882a593Smuzhiyun #include <linux/time.h>
16*4882a593Smuzhiyun #include <linux/ctype.h>
17*4882a593Smuzhiyun #include <asm/byteorder.h>
18*4882a593Smuzhiyun #include "zfs_common.h"
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun #include <zfs/zfs.h>
21*4882a593Smuzhiyun #include <zfs/zio.h>
22*4882a593Smuzhiyun #include <zfs/dnode.h>
23*4882a593Smuzhiyun #include <zfs/uberblock_impl.h>
24*4882a593Smuzhiyun #include <zfs/vdev_impl.h>
25*4882a593Smuzhiyun #include <zfs/zio_checksum.h>
26*4882a593Smuzhiyun #include <zfs/zap_impl.h>
27*4882a593Smuzhiyun #include <zfs/zap_leaf.h>
28*4882a593Smuzhiyun #include <zfs/zfs_znode.h>
29*4882a593Smuzhiyun #include <zfs/dmu.h>
30*4882a593Smuzhiyun #include <zfs/dmu_objset.h>
31*4882a593Smuzhiyun #include <zfs/dsl_dir.h>
32*4882a593Smuzhiyun #include <zfs/dsl_dataset.h>
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun #define	MATCH_BITS	6
35*4882a593Smuzhiyun #define	MATCH_MIN	3
36*4882a593Smuzhiyun #define	OFFSET_MASK	((1 << (16 - MATCH_BITS)) - 1)
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun /*
39*4882a593Smuzhiyun  * Decompression Entry - lzjb
40*4882a593Smuzhiyun  */
41*4882a593Smuzhiyun #ifndef	NBBY
42*4882a593Smuzhiyun #define	NBBY	8
43*4882a593Smuzhiyun #endif
44*4882a593Smuzhiyun 
45*4882a593Smuzhiyun int
lzjb_decompress(void * s_start,void * d_start,uint32_t s_len,uint32_t d_len)46*4882a593Smuzhiyun lzjb_decompress(void *s_start, void *d_start, uint32_t s_len,
47*4882a593Smuzhiyun 				uint32_t d_len)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun 	uint8_t *src = s_start;
50*4882a593Smuzhiyun 	uint8_t *dst = d_start;
51*4882a593Smuzhiyun 	uint8_t *d_end = (uint8_t *) d_start + d_len;
52*4882a593Smuzhiyun 	uint8_t *s_end = (uint8_t *) s_start + s_len;
53*4882a593Smuzhiyun 	uint8_t *cpy, copymap = 0;
54*4882a593Smuzhiyun 	int copymask = 1 << (NBBY - 1);
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun 	while (dst < d_end && src < s_end) {
57*4882a593Smuzhiyun 		if ((copymask <<= 1) == (1 << NBBY)) {
58*4882a593Smuzhiyun 			copymask = 1;
59*4882a593Smuzhiyun 			copymap = *src++;
60*4882a593Smuzhiyun 		}
61*4882a593Smuzhiyun 		if (src >= s_end) {
62*4882a593Smuzhiyun 			printf("lzjb decompression failed\n");
63*4882a593Smuzhiyun 			return ZFS_ERR_BAD_FS;
64*4882a593Smuzhiyun 		}
65*4882a593Smuzhiyun 		if (copymap & copymask) {
66*4882a593Smuzhiyun 			int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
67*4882a593Smuzhiyun 			int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
68*4882a593Smuzhiyun 			src += 2;
69*4882a593Smuzhiyun 			cpy = dst - offset;
70*4882a593Smuzhiyun 			if (src > s_end || cpy < (uint8_t *) d_start) {
71*4882a593Smuzhiyun 				printf("lzjb decompression failed\n");
72*4882a593Smuzhiyun 				return ZFS_ERR_BAD_FS;
73*4882a593Smuzhiyun 			}
74*4882a593Smuzhiyun 			while (--mlen >= 0 && dst < d_end)
75*4882a593Smuzhiyun 				*dst++ = *cpy++;
76*4882a593Smuzhiyun 		} else {
77*4882a593Smuzhiyun 			*dst++ = *src++;
78*4882a593Smuzhiyun 		}
79*4882a593Smuzhiyun 	}
80*4882a593Smuzhiyun 	if (dst < d_end) {
81*4882a593Smuzhiyun 		printf("lzjb decompression failed\n");
82*4882a593Smuzhiyun 		return ZFS_ERR_BAD_FS;
83*4882a593Smuzhiyun 	}
84*4882a593Smuzhiyun 	return ZFS_ERR_NONE;
85*4882a593Smuzhiyun }
86