xref: /illumos-gate/usr/src/uts/common/fs/zfs/zio_compress.c (revision 2411ecfcc7e4d3dc7fc3f78b9e50601e50a8a56c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /*
27  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
28  * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
29  */
30 
31 #include <sys/zfs_context.h>
32 #include <sys/compress.h>
33 #include <sys/spa.h>
34 #include <sys/zfeature.h>
35 #include <sys/zio.h>
36 #include <sys/zio_compress.h>
37 
38 /*
39  * Compression vectors.
40  */
41 zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
42 	{"inherit",		0,	NULL,		NULL},
43 	{"on",			0,	NULL,		NULL},
44 	{"uncompressed",	0,	NULL,		NULL},
45 	{"lzjb",		0,	lzjb_compress,	lzjb_decompress},
46 	{"empty",		0,	NULL,		NULL},
47 	{"gzip-1",		1,	gzip_compress,	gzip_decompress},
48 	{"gzip-2",		2,	gzip_compress,	gzip_decompress},
49 	{"gzip-3",		3,	gzip_compress,	gzip_decompress},
50 	{"gzip-4",		4,	gzip_compress,	gzip_decompress},
51 	{"gzip-5",		5,	gzip_compress,	gzip_decompress},
52 	{"gzip-6",		6,	gzip_compress,	gzip_decompress},
53 	{"gzip-7",		7,	gzip_compress,	gzip_decompress},
54 	{"gzip-8",		8,	gzip_compress,	gzip_decompress},
55 	{"gzip-9",		9,	gzip_compress,	gzip_decompress},
56 	{"zle",			64,	zle_compress,	zle_decompress},
57 	{"lz4",			0,	lz4_compress,	lz4_decompress}
58 };
59 
60 enum zio_compress
61 zio_compress_select(spa_t *spa, enum zio_compress child,
62     enum zio_compress parent)
63 {
64 	enum zio_compress result;
65 
66 	ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
67 	ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
68 	ASSERT(parent != ZIO_COMPRESS_INHERIT);
69 
70 	result = child;
71 	if (result == ZIO_COMPRESS_INHERIT)
72 		result = parent;
73 
74 	if (result == ZIO_COMPRESS_ON) {
75 		if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
76 			result = ZIO_COMPRESS_LZ4_ON_VALUE;
77 		else
78 			result = ZIO_COMPRESS_LEGACY_ON_VALUE;
79 	}
80 
81 	return (result);
82 }
83 
84 /*ARGSUSED*/
85 static int
86 zio_compress_zeroed_cb(void *data, size_t len, void *private)
87 {
88 	uint64_t *end = (uint64_t *)((char *)data + len);
89 	for (uint64_t *word = (uint64_t *)data; word < end; word++)
90 		if (*word != 0)
91 			return (1);
92 
93 	return (0);
94 }
95 
96 size_t
97 zio_compress_data(enum zio_compress c, abd_t *src, void *dst, size_t s_len)
98 {
99 	size_t c_len, d_len;
100 	zio_compress_info_t *ci = &zio_compress_table[c];
101 
102 	ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
103 	ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
104 
105 	/*
106 	 * If the data is all zeroes, we don't even need to allocate
107 	 * a block for it.  We indicate this by returning zero size.
108 	 */
109 	if (abd_iterate_func(src, 0, s_len, zio_compress_zeroed_cb, NULL) == 0)
110 		return (0);
111 
112 	if (c == ZIO_COMPRESS_EMPTY)
113 		return (s_len);
114 
115 	/* Compress at least 12.5% */
116 	d_len = s_len - (s_len >> 3);
117 
118 	/* No compression algorithms can read from ABDs directly */
119 	void *tmp = abd_borrow_buf_copy(src, s_len);
120 	c_len = ci->ci_compress(tmp, dst, s_len, d_len, ci->ci_level);
121 	abd_return_buf(src, tmp, s_len);
122 
123 	if (c_len > d_len)
124 		return (s_len);
125 
126 	ASSERT3U(c_len, <=, d_len);
127 	return (c_len);
128 }
129 
130 int
131 zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
132     size_t s_len, size_t d_len)
133 {
134 	zio_compress_info_t *ci = &zio_compress_table[c];
135 	if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
136 		return (SET_ERROR(EINVAL));
137 
138 	return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
139 }
140 
141 int
142 zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
143     size_t s_len, size_t d_len)
144 {
145 	void *tmp = abd_borrow_buf_copy(src, s_len);
146 	int ret = zio_decompress_data_buf(c, tmp, dst, s_len, d_len);
147 	abd_return_buf(src, tmp, s_len);
148 
149 	return (ret);
150 }
151