xref: /freebsd/sys/contrib/openzfs/module/zfs/zio_compress.c (revision 024248c933c5741a21c17eda63092f330dd98337)
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 https://opensource.org/licenses/CDDL-1.0.
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  */
29 
30 /*
31  * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
32  * Copyright (c) 2019, Klara Inc.
33  * Copyright (c) 2019, Allan Jude
34  */
35 
36 #include <sys/zfs_context.h>
37 #include <sys/spa.h>
38 #include <sys/zfeature.h>
39 #include <sys/zio.h>
40 #include <sys/zio_compress.h>
41 #include <sys/zstd/zstd.h>
42 
43 /*
44  * If nonzero, every 1/X decompression attempts will fail, simulating
45  * an undetected memory error.
46  */
47 static unsigned long zio_decompress_fail_fraction = 0;
48 
49 /*
50  * Compression vectors.
51  */
52 zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
53 	{"inherit",	0,	NULL,		NULL, NULL},
54 	{"on",		0,	NULL,		NULL, NULL},
55 	{"uncompressed", 0,	NULL,		NULL, NULL},
56 	{"lzjb",	0,	lzjb_compress,	lzjb_decompress, NULL},
57 	{"empty",	0,	NULL,		NULL, NULL},
58 	{"gzip-1",	1,	gzip_compress,	gzip_decompress, NULL},
59 	{"gzip-2",	2,	gzip_compress,	gzip_decompress, NULL},
60 	{"gzip-3",	3,	gzip_compress,	gzip_decompress, NULL},
61 	{"gzip-4",	4,	gzip_compress,	gzip_decompress, NULL},
62 	{"gzip-5",	5,	gzip_compress,	gzip_decompress, NULL},
63 	{"gzip-6",	6,	gzip_compress,	gzip_decompress, NULL},
64 	{"gzip-7",	7,	gzip_compress,	gzip_decompress, NULL},
65 	{"gzip-8",	8,	gzip_compress,	gzip_decompress, NULL},
66 	{"gzip-9",	9,	gzip_compress,	gzip_decompress, NULL},
67 	{"zle",		64,	zle_compress,	zle_decompress, NULL},
68 	{"lz4",		0,	lz4_compress_zfs, lz4_decompress_zfs, NULL},
69 	{"zstd",	ZIO_ZSTD_LEVEL_DEFAULT,	zfs_zstd_compress_wrap,
70 	    zfs_zstd_decompress, zfs_zstd_decompress_level},
71 };
72 
73 uint8_t
74 zio_complevel_select(spa_t *spa, enum zio_compress compress, uint8_t child,
75     uint8_t parent)
76 {
77 	(void) spa;
78 	uint8_t result;
79 
80 	if (!ZIO_COMPRESS_HASLEVEL(compress))
81 		return (0);
82 
83 	result = child;
84 	if (result == ZIO_COMPLEVEL_INHERIT)
85 		result = parent;
86 
87 	return (result);
88 }
89 
90 enum zio_compress
91 zio_compress_select(spa_t *spa, enum zio_compress child,
92     enum zio_compress parent)
93 {
94 	enum zio_compress result;
95 
96 	ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
97 	ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
98 	ASSERT(parent != ZIO_COMPRESS_INHERIT);
99 
100 	result = child;
101 	if (result == ZIO_COMPRESS_INHERIT)
102 		result = parent;
103 
104 	if (result == ZIO_COMPRESS_ON) {
105 		if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
106 			result = ZIO_COMPRESS_LZ4_ON_VALUE;
107 		else
108 			result = ZIO_COMPRESS_LEGACY_ON_VALUE;
109 	}
110 
111 	return (result);
112 }
113 
114 size_t
115 zio_compress_data(enum zio_compress c, abd_t *src, void **dst, size_t s_len,
116     uint8_t level)
117 {
118 	size_t c_len, d_len;
119 	uint8_t complevel;
120 	zio_compress_info_t *ci = &zio_compress_table[c];
121 
122 	ASSERT3U(c, <, ZIO_COMPRESS_FUNCTIONS);
123 	ASSERT3U(ci->ci_compress, !=, NULL);
124 	ASSERT3U(s_len, >, 0);
125 
126 	/* Compress at least 12.5% */
127 	d_len = s_len - (s_len >> 3);
128 
129 	complevel = ci->ci_level;
130 
131 	if (c == ZIO_COMPRESS_ZSTD) {
132 		/* If we don't know the level, we can't compress it */
133 		if (level == ZIO_COMPLEVEL_INHERIT)
134 			return (s_len);
135 
136 		if (level == ZIO_COMPLEVEL_DEFAULT)
137 			complevel = ZIO_ZSTD_LEVEL_DEFAULT;
138 		else
139 			complevel = level;
140 
141 		ASSERT3U(complevel, !=, ZIO_COMPLEVEL_INHERIT);
142 	}
143 
144 	if (*dst == NULL)
145 		*dst = zio_buf_alloc(s_len);
146 
147 	/* No compression algorithms can read from ABDs directly */
148 	void *tmp = abd_borrow_buf_copy(src, s_len);
149 	c_len = ci->ci_compress(tmp, *dst, s_len, d_len, complevel);
150 	abd_return_buf(src, tmp, s_len);
151 
152 	if (c_len > d_len)
153 		return (s_len);
154 
155 	ASSERT3U(c_len, <=, d_len);
156 	return (c_len);
157 }
158 
159 int
160 zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
161     size_t s_len, size_t d_len, uint8_t *level)
162 {
163 	zio_compress_info_t *ci = &zio_compress_table[c];
164 	if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
165 		return (SET_ERROR(EINVAL));
166 
167 	if (ci->ci_decompress_level != NULL && level != NULL)
168 		return (ci->ci_decompress_level(src, dst, s_len, d_len, level));
169 
170 	return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
171 }
172 
173 int
174 zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
175     size_t s_len, size_t d_len, uint8_t *level)
176 {
177 	void *tmp = abd_borrow_buf_copy(src, s_len);
178 	int ret = zio_decompress_data_buf(c, tmp, dst, s_len, d_len, level);
179 	abd_return_buf(src, tmp, s_len);
180 
181 	/*
182 	 * Decompression shouldn't fail, because we've already verified
183 	 * the checksum.  However, for extra protection (e.g. against bitflips
184 	 * in non-ECC RAM), we handle this error (and test it).
185 	 */
186 	if (zio_decompress_fail_fraction != 0 &&
187 	    random_in_range(zio_decompress_fail_fraction) == 0)
188 		ret = SET_ERROR(EINVAL);
189 
190 	return (ret);
191 }
192 
193 int
194 zio_compress_to_feature(enum zio_compress comp)
195 {
196 	switch (comp) {
197 	case ZIO_COMPRESS_ZSTD:
198 		return (SPA_FEATURE_ZSTD_COMPRESS);
199 	default:
200 		break;
201 	}
202 	return (SPA_FEATURE_NONE);
203 }
204