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 */
47static unsigned long zio_decompress_fail_fraction = 0;
48
49/*
50 * Compression vectors.
51 */
52zio_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
73uint8_t
74zio_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
90enum zio_compress
91zio_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
114static int
115zio_compress_zeroed_cb(void *data, size_t len, void *private)
116{
117	(void) private;
118
119	uint64_t *end = (uint64_t *)((char *)data + len);
120	for (uint64_t *word = (uint64_t *)data; word < end; word++)
121		if (*word != 0)
122			return (1);
123
124	return (0);
125}
126
127size_t
128zio_compress_data(enum zio_compress c, abd_t *src, void **dst, size_t s_len,
129    uint8_t level)
130{
131	size_t c_len, d_len;
132	uint8_t complevel;
133	zio_compress_info_t *ci = &zio_compress_table[c];
134
135	ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
136	ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
137
138	/*
139	 * If the data is all zeroes, we don't even need to allocate
140	 * a block for it.  We indicate this by returning zero size.
141	 */
142	if (abd_iterate_func(src, 0, s_len, zio_compress_zeroed_cb, NULL) == 0)
143		return (0);
144
145	if (c == ZIO_COMPRESS_EMPTY)
146		return (s_len);
147
148	/* Compress at least 12.5% */
149	d_len = s_len - (s_len >> 3);
150
151	complevel = ci->ci_level;
152
153	if (c == ZIO_COMPRESS_ZSTD) {
154		/* If we don't know the level, we can't compress it */
155		if (level == ZIO_COMPLEVEL_INHERIT)
156			return (s_len);
157
158		if (level == ZIO_COMPLEVEL_DEFAULT)
159			complevel = ZIO_ZSTD_LEVEL_DEFAULT;
160		else
161			complevel = level;
162
163		ASSERT3U(complevel, !=, ZIO_COMPLEVEL_INHERIT);
164	}
165
166	if (*dst == NULL)
167		*dst = zio_buf_alloc(s_len);
168
169	/* No compression algorithms can read from ABDs directly */
170	void *tmp = abd_borrow_buf_copy(src, s_len);
171	c_len = ci->ci_compress(tmp, *dst, s_len, d_len, complevel);
172	abd_return_buf(src, tmp, s_len);
173
174	if (c_len > d_len)
175		return (s_len);
176
177	ASSERT3U(c_len, <=, d_len);
178	return (c_len);
179}
180
181int
182zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
183    size_t s_len, size_t d_len, uint8_t *level)
184{
185	zio_compress_info_t *ci = &zio_compress_table[c];
186	if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
187		return (SET_ERROR(EINVAL));
188
189	if (ci->ci_decompress_level != NULL && level != NULL)
190		return (ci->ci_decompress_level(src, dst, s_len, d_len, level));
191
192	return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
193}
194
195int
196zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
197    size_t s_len, size_t d_len, uint8_t *level)
198{
199	void *tmp = abd_borrow_buf_copy(src, s_len);
200	int ret = zio_decompress_data_buf(c, tmp, dst, s_len, d_len, level);
201	abd_return_buf(src, tmp, s_len);
202
203	/*
204	 * Decompression shouldn't fail, because we've already verified
205	 * the checksum.  However, for extra protection (e.g. against bitflips
206	 * in non-ECC RAM), we handle this error (and test it).
207	 */
208	if (zio_decompress_fail_fraction != 0 &&
209	    random_in_range(zio_decompress_fail_fraction) == 0)
210		ret = SET_ERROR(EINVAL);
211
212	return (ret);
213}
214
215int
216zio_compress_to_feature(enum zio_compress comp)
217{
218	switch (comp) {
219	case ZIO_COMPRESS_ZSTD:
220		return (SPA_FEATURE_ZSTD_COMPRESS);
221	default:
222		break;
223	}
224	return (SPA_FEATURE_NONE);
225}
226