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 by Delphix. All rights reserved.
32 */
33
34 #include <sys/zfs_context.h>
35 #include <sys/compress.h>
36 #include <sys/kstat.h>
37 #include <sys/spa.h>
38 #include <sys/zfeature.h>
39 #include <sys/zio.h>
40 #include <sys/zio_compress.h>
41
42 typedef struct zcomp_stats {
43 kstat_named_t zcompstat_attempts;
44 kstat_named_t zcompstat_empty;
45 kstat_named_t zcompstat_skipped_insufficient_gain;
46 } zcomp_stats_t;
47
48 static zcomp_stats_t zcomp_stats = {
49 { "attempts", KSTAT_DATA_UINT64 },
50 { "empty", KSTAT_DATA_UINT64 },
51 { "skipped_insufficient_gain", KSTAT_DATA_UINT64 }
52 };
53
54 #define ZCOMPSTAT_INCR(stat, val) \
55 atomic_add_64(&zcomp_stats.stat.value.ui64, (val));
56
57 #define ZCOMPSTAT_BUMP(stat) ZCOMPSTAT_INCR(stat, 1);
58
59 kstat_t *zcomp_ksp;
60
61 /*
62 * Compression vectors.
63 */
64
65 zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
66 {NULL, NULL, 0, "inherit"},
67 {NULL, NULL, 0, "on"},
68 {NULL, NULL, 0, "uncompressed"},
69 {lzjb_compress, lzjb_decompress, 0, "lzjb"},
70 {NULL, NULL, 0, "empty"},
71 {gzip_compress, gzip_decompress, 1, "gzip-1"},
72 {gzip_compress, gzip_decompress, 2, "gzip-2"},
73 {gzip_compress, gzip_decompress, 3, "gzip-3"},
74 {gzip_compress, gzip_decompress, 4, "gzip-4"},
75 {gzip_compress, gzip_decompress, 5, "gzip-5"},
76 {gzip_compress, gzip_decompress, 6, "gzip-6"},
77 {gzip_compress, gzip_decompress, 7, "gzip-7"},
78 {gzip_compress, gzip_decompress, 8, "gzip-8"},
79 {gzip_compress, gzip_decompress, 9, "gzip-9"},
80 {zle_compress, zle_decompress, 64, "zle"},
81 {lz4_compress, lz4_decompress, 0, "lz4"},
82 };
83
84 enum zio_compress
zio_compress_select(spa_t * spa,enum zio_compress child,enum zio_compress parent)85 zio_compress_select(spa_t *spa, enum zio_compress child,
86 enum zio_compress parent)
87 {
88 enum zio_compress result;
89
90 ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
91 ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
92 ASSERT(parent != ZIO_COMPRESS_INHERIT);
93
94 result = child;
95 if (result == ZIO_COMPRESS_INHERIT)
96 result = parent;
97
98 if (result == ZIO_COMPRESS_ON) {
99 if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
100 result = ZIO_COMPRESS_LZ4_ON_VALUE;
101 else
102 result = ZIO_COMPRESS_LEGACY_ON_VALUE;
103 }
104
105 return (result);
106 }
107
108 size_t
zio_compress_data(enum zio_compress c,void * src,void * dst,size_t s_len)109 zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len)
110 {
111 uint64_t *word, *word_end;
112 size_t c_len, d_len;
113 zio_compress_info_t *ci = &zio_compress_table[c];
114
115 ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
116 ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
117
118 ZCOMPSTAT_BUMP(zcompstat_attempts);
119
120 /*
121 * If the data is all zeroes, we don't even need to allocate
122 * a block for it. We indicate this by returning zero size.
123 */
124 word_end = (uint64_t *)((char *)src + s_len);
125 for (word = src; word < word_end; word++)
126 if (*word != 0)
127 break;
128
129 if (word == word_end) {
130 ZCOMPSTAT_BUMP(zcompstat_empty);
131 return (0);
132 }
133
134 if (c == ZIO_COMPRESS_EMPTY)
135 return (s_len);
136
137 /* Compress at least 12.5% */
138 d_len = s_len - (s_len >> 3);
139 c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level);
140
141 if (c_len > d_len) {
142 ZCOMPSTAT_BUMP(zcompstat_skipped_insufficient_gain);
143 return (s_len);
144 }
145
146 ASSERT3U(c_len, <=, d_len);
147 return (c_len);
148 }
149
150 int
zio_decompress_data(enum zio_compress c,void * src,void * dst,size_t s_len,size_t d_len)151 zio_decompress_data(enum zio_compress c, void *src, void *dst,
152 size_t s_len, size_t d_len)
153 {
154 zio_compress_info_t *ci = &zio_compress_table[c];
155
156 if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
157 return (SET_ERROR(EINVAL));
158
159 return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
160 }
161
162 void
zio_compress_init(void)163 zio_compress_init(void)
164 {
165
166 zcomp_ksp = kstat_create("zfs", 0, "zcompstats", "misc",
167 KSTAT_TYPE_NAMED, sizeof (zcomp_stats) / sizeof (kstat_named_t),
168 KSTAT_FLAG_VIRTUAL);
169
170 if (zcomp_ksp != NULL) {
171 zcomp_ksp->ks_data = &zcomp_stats;
172 kstat_install(zcomp_ksp);
173 }
174 }
175
176 void
zio_compress_fini(void)177 zio_compress_fini(void)
178 {
179 if (zcomp_ksp != NULL) {
180 kstat_delete(zcomp_ksp);
181 zcomp_ksp = NULL;
182 }
183 }
184