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 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 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 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 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 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