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 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/zfs_context.h> 30 #include <sys/compress.h> 31 #include <sys/spa.h> 32 #include <sys/zio.h> 33 #include <sys/zio_compress.h> 34 35 /* 36 * Compression vectors. 37 */ 38 39 zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = { 40 {NULL, NULL, 0, "inherit"}, 41 {NULL, NULL, 0, "on"}, 42 {NULL, NULL, 0, "uncompressed"}, 43 {lzjb_compress, lzjb_decompress, 0, "lzjb"}, 44 {NULL, NULL, 0, "empty"}, 45 {gzip_compress, gzip_decompress, 1, "gzip-1"}, 46 {gzip_compress, gzip_decompress, 2, "gzip-2"}, 47 {gzip_compress, gzip_decompress, 3, "gzip-3"}, 48 {gzip_compress, gzip_decompress, 4, "gzip-4"}, 49 {gzip_compress, gzip_decompress, 5, "gzip-5"}, 50 {gzip_compress, gzip_decompress, 6, "gzip-6"}, 51 {gzip_compress, gzip_decompress, 7, "gzip-7"}, 52 {gzip_compress, gzip_decompress, 8, "gzip-8"}, 53 {gzip_compress, gzip_decompress, 9, "gzip-9"}, 54 }; 55 56 uint8_t 57 zio_compress_select(uint8_t child, uint8_t parent) 58 { 59 ASSERT(child < ZIO_COMPRESS_FUNCTIONS); 60 ASSERT(parent < ZIO_COMPRESS_FUNCTIONS); 61 ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON); 62 63 if (child == ZIO_COMPRESS_INHERIT) 64 return (parent); 65 66 if (child == ZIO_COMPRESS_ON) 67 return (ZIO_COMPRESS_ON_VALUE); 68 69 return (child); 70 } 71 72 int 73 zio_compress_data(int cpfunc, void *src, uint64_t srcsize, void **destp, 74 uint64_t *destsizep, uint64_t *destbufsizep) 75 { 76 uint64_t *word, *word_end; 77 uint64_t ciosize, gapsize, destbufsize; 78 zio_compress_info_t *ci = &zio_compress_table[cpfunc]; 79 char *dest; 80 uint_t allzero; 81 82 ASSERT((uint_t)cpfunc < ZIO_COMPRESS_FUNCTIONS); 83 ASSERT((uint_t)cpfunc == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL); 84 85 /* 86 * If the data is all zeroes, we don't even need to allocate 87 * a block for it. We indicate this by setting *destsizep = 0. 88 */ 89 allzero = 1; 90 word = src; 91 word_end = (uint64_t *)(uintptr_t)((uintptr_t)word + srcsize); 92 while (word < word_end) { 93 if (*word++ != 0) { 94 allzero = 0; 95 break; 96 } 97 } 98 if (allzero) { 99 *destp = NULL; 100 *destsizep = 0; 101 *destbufsizep = 0; 102 return (1); 103 } 104 105 if (cpfunc == ZIO_COMPRESS_EMPTY) 106 return (0); 107 108 /* Compress at least 12.5% */ 109 destbufsize = P2ALIGN(srcsize - (srcsize >> 3), SPA_MINBLOCKSIZE); 110 if (destbufsize == 0) 111 return (0); 112 dest = zio_buf_alloc(destbufsize); 113 114 ciosize = ci->ci_compress(src, dest, (size_t)srcsize, 115 (size_t)destbufsize, ci->ci_level); 116 if (ciosize > destbufsize) { 117 zio_buf_free(dest, destbufsize); 118 return (0); 119 } 120 121 /* Cool. We compressed at least as much as we were hoping to. */ 122 123 /* For security, make sure we don't write random heap crap to disk */ 124 gapsize = P2ROUNDUP(ciosize, SPA_MINBLOCKSIZE) - ciosize; 125 if (gapsize != 0) { 126 bzero(dest + ciosize, gapsize); 127 ciosize += gapsize; 128 } 129 130 ASSERT3U(ciosize, <=, destbufsize); 131 ASSERT(P2PHASE(ciosize, SPA_MINBLOCKSIZE) == 0); 132 *destp = dest; 133 *destsizep = ciosize; 134 *destbufsizep = destbufsize; 135 136 return (1); 137 } 138 139 int 140 zio_decompress_data(int cpfunc, void *src, uint64_t srcsize, 141 void *dest, uint64_t destsize) 142 { 143 zio_compress_info_t *ci = &zio_compress_table[cpfunc]; 144 145 ASSERT((uint_t)cpfunc < ZIO_COMPRESS_FUNCTIONS); 146 147 return (ci->ci_decompress(src, dest, srcsize, destsize, ci->ci_level)); 148 } 149