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/spa.h> 37 #include <sys/zio.h> 38 #include <sys/zio_compress.h> 39 40 /* 41 * Compression vectors. 42 */ 43 44 zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = { 45 {NULL, NULL, 0, "inherit"}, 46 {NULL, NULL, 0, "on"}, 47 {NULL, NULL, 0, "uncompressed"}, 48 {lzjb_compress, lzjb_decompress, 0, "lzjb"}, 49 {NULL, NULL, 0, "empty"}, 50 {gzip_compress, gzip_decompress, 1, "gzip-1"}, 51 {gzip_compress, gzip_decompress, 2, "gzip-2"}, 52 {gzip_compress, gzip_decompress, 3, "gzip-3"}, 53 {gzip_compress, gzip_decompress, 4, "gzip-4"}, 54 {gzip_compress, gzip_decompress, 5, "gzip-5"}, 55 {gzip_compress, gzip_decompress, 6, "gzip-6"}, 56 {gzip_compress, gzip_decompress, 7, "gzip-7"}, 57 {gzip_compress, gzip_decompress, 8, "gzip-8"}, 58 {gzip_compress, gzip_decompress, 9, "gzip-9"}, 59 {zle_compress, zle_decompress, 64, "zle"}, 60 {lz4_compress, lz4_decompress, 0, "lz4"}, 61 }; 62 63 enum zio_compress 64 zio_compress_select(enum zio_compress child, enum zio_compress parent) 65 { 66 ASSERT(child < ZIO_COMPRESS_FUNCTIONS); 67 ASSERT(parent < ZIO_COMPRESS_FUNCTIONS); 68 ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON); 69 70 if (child == ZIO_COMPRESS_INHERIT) 71 return (parent); 72 73 if (child == ZIO_COMPRESS_ON) 74 return (ZIO_COMPRESS_ON_VALUE); 75 76 return (child); 77 } 78 79 size_t 80 zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len) 81 { 82 uint64_t *word, *word_end; 83 size_t c_len, d_len, r_len; 84 zio_compress_info_t *ci = &zio_compress_table[c]; 85 86 ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS); 87 ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL); 88 89 /* 90 * If the data is all zeroes, we don't even need to allocate 91 * a block for it. We indicate this by returning zero size. 92 */ 93 word_end = (uint64_t *)((char *)src + s_len); 94 for (word = src; word < word_end; word++) 95 if (*word != 0) 96 break; 97 98 if (word == word_end) 99 return (0); 100 101 if (c == ZIO_COMPRESS_EMPTY) 102 return (s_len); 103 104 /* Compress at least 12.5% */ 105 d_len = P2ALIGN(s_len - (s_len >> 3), (size_t)SPA_MINBLOCKSIZE); 106 if (d_len == 0) 107 return (s_len); 108 109 c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level); 110 111 if (c_len > d_len) 112 return (s_len); 113 114 /* 115 * Cool. We compressed at least as much as we were hoping to. 116 * For both security and repeatability, pad out the last sector. 117 */ 118 r_len = P2ROUNDUP(c_len, (size_t)SPA_MINBLOCKSIZE); 119 if (r_len > c_len) { 120 bzero((char *)dst + c_len, r_len - c_len); 121 c_len = r_len; 122 } 123 124 ASSERT3U(c_len, <=, d_len); 125 ASSERT(P2PHASE(c_len, (size_t)SPA_MINBLOCKSIZE) == 0); 126 127 return (c_len); 128 } 129 130 int 131 zio_decompress_data(enum zio_compress c, void *src, void *dst, 132 size_t s_len, size_t d_len) 133 { 134 zio_compress_info_t *ci = &zio_compress_table[c]; 135 136 if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL) 137 return (SET_ERROR(EINVAL)); 138 139 return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level)); 140 } 141