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/zio.h> 39#include <sys/zio_compress.h> 40 41typedef struct zcomp_stats { 42 kstat_named_t zcompstat_attempts; 43 kstat_named_t zcompstat_empty; 44 kstat_named_t zcompstat_skipped_minblocksize; 45 kstat_named_t zcompstat_skipped_insufficient_gain; 46} zcomp_stats_t; 47 48static zcomp_stats_t zcomp_stats = { 49 { "attempts", KSTAT_DATA_UINT64 }, 50 { "empty", KSTAT_DATA_UINT64 }, 51 { "skipped_minblocksize", KSTAT_DATA_UINT64 }, 52 { "skipped_insufficient_gain", KSTAT_DATA_UINT64 } 53}; 54 55#define ZCOMPSTAT_INCR(stat, val) \ 56 atomic_add_64(&zcomp_stats.stat.value.ui64, (val)); 57 58#define ZCOMPSTAT_BUMP(stat) ZCOMPSTAT_INCR(stat, 1); 59 60kstat_t *zcomp_ksp; 61 62/* 63 * Compression vectors. 64 */ 65 66zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = { 67 {NULL, NULL, 0, "inherit"}, 68 {NULL, NULL, 0, "on"}, 69 {NULL, NULL, 0, "uncompressed"}, 70 {lzjb_compress, lzjb_decompress, 0, "lzjb"}, 71 {NULL, NULL, 0, "empty"}, 72 {gzip_compress, gzip_decompress, 1, "gzip-1"}, 73 {gzip_compress, gzip_decompress, 2, "gzip-2"}, 74 {gzip_compress, gzip_decompress, 3, "gzip-3"}, 75 {gzip_compress, gzip_decompress, 4, "gzip-4"}, 76 {gzip_compress, gzip_decompress, 5, "gzip-5"}, 77 {gzip_compress, gzip_decompress, 6, "gzip-6"}, 78 {gzip_compress, gzip_decompress, 7, "gzip-7"}, 79 {gzip_compress, gzip_decompress, 8, "gzip-8"}, 80 {gzip_compress, gzip_decompress, 9, "gzip-9"}, 81 {zle_compress, zle_decompress, 64, "zle"}, 82 {lz4_compress, lz4_decompress, 0, "lz4"}, 83}; 84 85enum zio_compress 86zio_compress_select(enum zio_compress child, enum zio_compress parent) 87{ 88 ASSERT(child < ZIO_COMPRESS_FUNCTIONS); 89 ASSERT(parent < ZIO_COMPRESS_FUNCTIONS); 90 ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON); 91 92 if (child == ZIO_COMPRESS_INHERIT) 93 return (parent); 94 95 if (child == ZIO_COMPRESS_ON) 96 return (ZIO_COMPRESS_ON_VALUE); 97 98 return (child); 99} 100 101size_t 102zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len, 103 size_t minblocksize) 104{ 105 uint64_t *word, *word_end; 106 size_t c_len, d_len, r_len; 107 zio_compress_info_t *ci = &zio_compress_table[c]; 108 109 ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS); 110 ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL); 111 112 ZCOMPSTAT_BUMP(zcompstat_attempts); 113 114 /* 115 * If the data is all zeroes, we don't even need to allocate 116 * a block for it. We indicate this by returning zero size. 117 */ 118 word_end = (uint64_t *)((char *)src + s_len); 119 for (word = src; word < word_end; word++) 120 if (*word != 0) 121 break; 122 123 if (word == word_end) { 124 ZCOMPSTAT_BUMP(zcompstat_empty); 125 return (0); 126 } 127 128 if (c == ZIO_COMPRESS_EMPTY) 129 return (s_len); 130 131 /* Compress at least 12.5% */ 132 d_len = P2ALIGN(s_len - (s_len >> 3), minblocksize); 133 if (d_len == 0) { 134 ZCOMPSTAT_BUMP(zcompstat_skipped_minblocksize); 135 return (s_len); 136 } 137 138 c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level); 139 140 if (c_len > d_len) { 141 ZCOMPSTAT_BUMP(zcompstat_skipped_insufficient_gain); 142 return (s_len); 143 } 144 145 /* 146 * Cool. We compressed at least as much as we were hoping to. 147 * For both security and repeatability, pad out the last sector. 148 */ 149 r_len = P2ROUNDUP(c_len, minblocksize); 150 if (r_len > c_len) { 151 bzero((char *)dst + c_len, r_len - c_len); 152 c_len = r_len; 153 } 154 155 ASSERT3U(c_len, <=, d_len); 156 ASSERT(P2PHASE(c_len, minblocksize) == 0); 157 158 return (c_len); 159} 160 161int 162zio_decompress_data(enum zio_compress c, void *src, void *dst, 163 size_t s_len, size_t d_len) 164{ 165 zio_compress_info_t *ci = &zio_compress_table[c]; 166 167 if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL) 168 return (SET_ERROR(EINVAL)); 169 170 return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level)); 171} 172 173void 174zio_compress_init(void) 175{ 176 177 zcomp_ksp = kstat_create("zfs", 0, "zcompstats", "misc", 178 KSTAT_TYPE_NAMED, sizeof (zcomp_stats) / sizeof (kstat_named_t), 179 KSTAT_FLAG_VIRTUAL); 180 181 if (zcomp_ksp != NULL) { 182 zcomp_ksp->ks_data = &zcomp_stats; 183 kstat_install(zcomp_ksp); 184 } 185} 186 187void 188zio_compress_fini(void) 189{ 190 if (zcomp_ksp != NULL) { 191 kstat_delete(zcomp_ksp); 192 zcomp_ksp = NULL; 193 } 194} 195