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, 2018 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 * If nonzero, every 1/X decompression attempts will fail, simulating
40 * an undetected memory error.
41 */
42 uint64_t zio_decompress_fail_fraction = 0;
43
44 /*
45 * Compression vectors.
46 */
47 zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
48 {"inherit", 0, NULL, NULL},
49 {"on", 0, NULL, NULL},
50 {"uncompressed", 0, NULL, NULL},
51 {"lzjb", 0, lzjb_compress, lzjb_decompress},
52 {"empty", 0, NULL, NULL},
53 {"gzip-1", 1, gzip_compress, gzip_decompress},
54 {"gzip-2", 2, gzip_compress, gzip_decompress},
55 {"gzip-3", 3, gzip_compress, gzip_decompress},
56 {"gzip-4", 4, gzip_compress, gzip_decompress},
57 {"gzip-5", 5, gzip_compress, gzip_decompress},
58 {"gzip-6", 6, gzip_compress, gzip_decompress},
59 {"gzip-7", 7, gzip_compress, gzip_decompress},
60 {"gzip-8", 8, gzip_compress, gzip_decompress},
61 {"gzip-9", 9, gzip_compress, gzip_decompress},
62 {"zle", 64, zle_compress, zle_decompress},
63 {"lz4", 0, lz4_compress, lz4_decompress}
64 };
65
66 enum zio_compress
zio_compress_select(spa_t * spa,enum zio_compress child,enum zio_compress parent)67 zio_compress_select(spa_t *spa, enum zio_compress child,
68 enum zio_compress parent)
69 {
70 enum zio_compress result;
71
72 ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
73 ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
74 ASSERT(parent != ZIO_COMPRESS_INHERIT);
75
76 result = child;
77 if (result == ZIO_COMPRESS_INHERIT)
78 result = parent;
79
80 if (result == ZIO_COMPRESS_ON) {
81 if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
82 result = ZIO_COMPRESS_LZ4_ON_VALUE;
83 else
84 result = ZIO_COMPRESS_LEGACY_ON_VALUE;
85 }
86
87 return (result);
88 }
89
90 /*ARGSUSED*/
91 static int
zio_compress_zeroed_cb(void * data,size_t len,void * private)92 zio_compress_zeroed_cb(void *data, size_t len, void *private)
93 {
94 uint64_t *end = (uint64_t *)((char *)data + len);
95 for (uint64_t *word = (uint64_t *)data; word < end; word++)
96 if (*word != 0)
97 return (1);
98
99 return (0);
100 }
101
102 size_t
zio_compress_data(enum zio_compress c,abd_t * src,void * dst,size_t s_len)103 zio_compress_data(enum zio_compress c, abd_t *src, void *dst, size_t s_len)
104 {
105 size_t c_len, d_len;
106 zio_compress_info_t *ci = &zio_compress_table[c];
107
108 ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
109 ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
110
111 /*
112 * If the data is all zeroes, we don't even need to allocate
113 * a block for it. We indicate this by returning zero size.
114 */
115 if (abd_iterate_func(src, 0, s_len, zio_compress_zeroed_cb, NULL) == 0)
116 return (0);
117
118 if (c == ZIO_COMPRESS_EMPTY)
119 return (s_len);
120
121 /* Compress at least 12.5% */
122 d_len = s_len - (s_len >> 3);
123
124 /* No compression algorithms can read from ABDs directly */
125 void *tmp = abd_borrow_buf_copy(src, s_len);
126 c_len = ci->ci_compress(tmp, dst, s_len, d_len, ci->ci_level);
127 abd_return_buf(src, tmp, s_len);
128
129 if (c_len > d_len)
130 return (s_len);
131
132 ASSERT3U(c_len, <=, d_len);
133 return (c_len);
134 }
135
136 int
zio_decompress_data_buf(enum zio_compress c,void * src,void * dst,size_t s_len,size_t d_len)137 zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
138 size_t s_len, size_t d_len)
139 {
140 zio_compress_info_t *ci = &zio_compress_table[c];
141 if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
142 return (SET_ERROR(EINVAL));
143
144 return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
145 }
146
147 void *zio_decompress_failed_buf;
148
149 int
zio_decompress_data(enum zio_compress c,abd_t * src,void * dst,size_t s_len,size_t d_len)150 zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
151 size_t s_len, size_t d_len)
152 {
153 void *tmp = abd_borrow_buf_copy(src, s_len);
154 int ret = zio_decompress_data_buf(c, tmp, dst, s_len, d_len);
155
156 /*
157 * Decompression shouldn't fail, because we've already verified
158 * the checksum. However, for extra protection (e.g. against bitflips
159 * in non-ECC RAM), we handle this error (and test it).
160 */
161 if (ret != 0) {
162 zio_decompress_failed_buf = kmem_alloc(s_len, KM_SLEEP);
163 bcopy(tmp, zio_decompress_failed_buf, s_len);
164 panic("decompression failed "
165 "err=%u c=%u buf=%p s_len=%u d_len=%u",
166 ret, (int)c, zio_decompress_failed_buf,
167 (int)s_len, (int)d_len);
168 }
169
170 abd_return_buf(src, tmp, s_len);
171
172 if (zio_decompress_fail_fraction != 0 &&
173 spa_get_random(zio_decompress_fail_fraction) == 0)
174 ret = SET_ERROR(EINVAL);
175
176 return (ret);
177 }
178