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 */
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 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,
70 zfs_zstd_decompress, zfs_zstd_decompress_level},
71 };
72
73 uint8_t
zio_complevel_select(spa_t * spa,enum zio_compress compress,uint8_t child,uint8_t parent)74 zio_complevel_select(spa_t *spa, enum zio_compress compress, uint8_t child,
75 uint8_t parent)
76 {
77 uint8_t result;
78
79 if (!ZIO_COMPRESS_HASLEVEL(compress))
80 return (0);
81
82 result = child;
83 if (result == ZIO_COMPLEVEL_INHERIT)
84 result = parent;
85
86 return (result);
87 }
88
89 enum zio_compress
zio_compress_select(spa_t * spa,enum zio_compress child,enum zio_compress parent)90 zio_compress_select(spa_t *spa, enum zio_compress child,
91 enum zio_compress parent)
92 {
93 enum zio_compress result;
94
95 ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
96 ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
97 ASSERT(parent != ZIO_COMPRESS_INHERIT);
98
99 result = child;
100 if (result == ZIO_COMPRESS_INHERIT)
101 result = parent;
102
103 if (result == ZIO_COMPRESS_ON) {
104 if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
105 result = ZIO_COMPRESS_LZ4_ON_VALUE;
106 else
107 result = ZIO_COMPRESS_LEGACY_ON_VALUE;
108 }
109
110 return (result);
111 }
112
113 /*ARGSUSED*/
114 static int
zio_compress_zeroed_cb(void * data,size_t len,void * private)115 zio_compress_zeroed_cb(void *data, size_t len, void *private)
116 {
117 uint64_t *end = (uint64_t *)((char *)data + len);
118 for (uint64_t *word = (uint64_t *)data; word < end; word++)
119 if (*word != 0)
120 return (1);
121
122 return (0);
123 }
124
125 size_t
zio_compress_data(enum zio_compress c,abd_t * src,void * dst,size_t s_len,uint8_t level)126 zio_compress_data(enum zio_compress c, abd_t *src, void *dst, size_t s_len,
127 uint8_t level)
128 {
129 size_t c_len, d_len;
130 uint8_t complevel;
131 zio_compress_info_t *ci = &zio_compress_table[c];
132
133 ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
134 ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
135
136 /*
137 * If the data is all zeroes, we don't even need to allocate
138 * a block for it. We indicate this by returning zero size.
139 */
140 if (abd_iterate_func(src, 0, s_len, zio_compress_zeroed_cb, NULL) == 0)
141 return (0);
142
143 if (c == ZIO_COMPRESS_EMPTY)
144 return (s_len);
145
146 /* Compress at least 12.5% */
147 d_len = s_len - (s_len >> 3);
148
149 complevel = ci->ci_level;
150
151 if (c == ZIO_COMPRESS_ZSTD) {
152 /* If we don't know the level, we can't compress it */
153 if (level == ZIO_COMPLEVEL_INHERIT)
154 return (s_len);
155
156 if (level == ZIO_COMPLEVEL_DEFAULT)
157 complevel = ZIO_ZSTD_LEVEL_DEFAULT;
158 else
159 complevel = level;
160
161 ASSERT3U(complevel, !=, ZIO_COMPLEVEL_INHERIT);
162 }
163
164 /* No compression algorithms can read from ABDs directly */
165 void *tmp = abd_borrow_buf_copy(src, s_len);
166 c_len = ci->ci_compress(tmp, dst, s_len, d_len, complevel);
167 abd_return_buf(src, tmp, s_len);
168
169 if (c_len > d_len)
170 return (s_len);
171
172 ASSERT3U(c_len, <=, d_len);
173 return (c_len);
174 }
175
176 int
zio_decompress_data_buf(enum zio_compress c,void * src,void * dst,size_t s_len,size_t d_len,uint8_t * level)177 zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
178 size_t s_len, size_t d_len, uint8_t *level)
179 {
180 zio_compress_info_t *ci = &zio_compress_table[c];
181 if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
182 return (SET_ERROR(EINVAL));
183
184 if (ci->ci_decompress_level != NULL && level != NULL)
185 return (ci->ci_decompress_level(src, dst, s_len, d_len, level));
186
187 return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
188 }
189
190 int
zio_decompress_data(enum zio_compress c,abd_t * src,void * dst,size_t s_len,size_t d_len,uint8_t * level)191 zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
192 size_t s_len, size_t d_len, uint8_t *level)
193 {
194 void *tmp = abd_borrow_buf_copy(src, s_len);
195 int ret = zio_decompress_data_buf(c, tmp, dst, s_len, d_len, level);
196 abd_return_buf(src, tmp, s_len);
197
198 /*
199 * Decompression shouldn't fail, because we've already verified
200 * the checksum. However, for extra protection (e.g. against bitflips
201 * in non-ECC RAM), we handle this error (and test it).
202 */
203 if (zio_decompress_fail_fraction != 0 &&
204 spa_get_random(zio_decompress_fail_fraction) == 0)
205 ret = SET_ERROR(EINVAL);
206
207 return (ret);
208 }
209
210 int
zio_compress_to_feature(enum zio_compress comp)211 zio_compress_to_feature(enum zio_compress comp)
212 {
213 switch (comp) {
214 case ZIO_COMPRESS_ZSTD:
215 return (SPA_FEATURE_ZSTD_COMPRESS);
216 default:
217 /* fallthru */;
218 }
219 return (SPA_FEATURE_NONE);
220 }
221