module/zfs/zio_compress.c

   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  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  26  * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
  27  * Copyright (c) 2019, 2024, Klara, Inc.
  28  * Copyright (c) 2019, Allan Jude
  29  * Copyright (c) 2021, 2024 by George Melikov. All rights reserved.
  30  */
  31
  32 #include <sys/zfs_context.h>
  33 #include <sys/spa.h>
  34 #include <sys/zfeature.h>
  35 #include <sys/zio.h>
  36 #include <sys/zio_compress.h>
  37 #include <sys/zstd/zstd.h>
  38
  39 /*
  40  * If nonzero, every 1/X decompression attempts will fail, simulating
  41  * an undetected memory error.
  42  */
  43 static unsigned long zio_decompress_fail_fraction = 0;
  44
  45 /*
  46  * Compression vectors.
  47  *
  48  * NOTE: DO NOT CHANGE THE NAMES OF THESE COMPRESSION FUNCTIONS.
  49  * THEY ARE USED AS ZAP KEY NAMES BY FAST DEDUP AND THEREFORE
  50  * PART OF THE ON-DISK FORMAT.
  51  */
  52 zio_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,
  57             zfs_lzjb_compress,  zfs_lzjb_decompress, NULL},
  58         {"empty",       0,      NULL,   NULL, NULL},
  59         {"gzip-1",      1,
  60             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  61         {"gzip-2",      2,
  62             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  63         {"gzip-3",      3,
  64             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  65         {"gzip-4",      4,
  66             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  67         {"gzip-5",      5,
  68             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  69         {"gzip-6",      6,
  70             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  71         {"gzip-7",      7,
  72             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  73         {"gzip-8",      8,
  74             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  75         {"gzip-9",      9,
  76             zfs_gzip_compress,  zfs_gzip_decompress, NULL},
  77         {"zle",         64,
  78             zfs_zle_compress,   zfs_zle_decompress, NULL},
  79         {"lz4",         0,
  80             zfs_lz4_compress,   zfs_lz4_decompress, NULL},
  81         {"zstd",        ZIO_ZSTD_LEVEL_DEFAULT,
  82             zfs_zstd_compress,  zfs_zstd_decompress, zfs_zstd_decompress_level},
  83 };
  84
  85 uint8_t
  86 zio_complevel_select(spa_t *spa, enum zio_compress compress, uint8_t child,
  87     uint8_t parent)
  88 {
  89         (void) spa;
  90         uint8_t result;
  91
  92         if (!ZIO_COMPRESS_HASLEVEL(compress))
  93                 return (0);
  94
  95         result = child;
  96         if (result == ZIO_COMPLEVEL_INHERIT)
  97                 result = parent;
  98
  99         return (result);
 100 }
 101
 102 enum zio_compress
 103 zio_compress_select(spa_t *spa, enum zio_compress child,
 104     enum zio_compress parent)
 105 {
 106         enum zio_compress result;
 107
 108         ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
 109         ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
 110         ASSERT(parent != ZIO_COMPRESS_INHERIT);
 111
 112         result = child;
 113         if (result == ZIO_COMPRESS_INHERIT)
 114                 result = parent;
 115
 116         if (result == ZIO_COMPRESS_ON) {
 117                 if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
 118                         result = ZIO_COMPRESS_LZ4_ON_VALUE;
 119                 else
 120                         result = ZIO_COMPRESS_LEGACY_ON_VALUE;
 121         }
 122
 123         return (result);
 124 }
 125
 126 size_t
 127 zio_compress_data(enum zio_compress c, abd_t *src, abd_t **dst, size_t s_len,
 128     size_t d_len, uint8_t level)
 129 {
 130         size_t c_len;
 131         uint8_t complevel;
 132         zio_compress_info_t *ci = &zio_compress_table[c];
 133
 134         ASSERT3U(ci->ci_compress, !=, NULL);
 135         ASSERT3U(s_len, >, 0);
 136
 137         complevel = ci->ci_level;
 138
 139         if (c == ZIO_COMPRESS_ZSTD) {
 140                 /* If we don't know the level, we can't compress it */
 141                 if (level == ZIO_COMPLEVEL_INHERIT)
 142                         return (s_len);
 143
 144                 if (level == ZIO_COMPLEVEL_DEFAULT)
 145                         complevel = ZIO_ZSTD_LEVEL_DEFAULT;
 146                 else
 147                         complevel = level;
 148
 149                 ASSERT3U(complevel, !=, ZIO_COMPLEVEL_INHERIT);
 150         }
 151
 152         if (*dst == NULL)
 153                 *dst = abd_alloc_sametype(src, s_len);
 154
 155         c_len = ci->ci_compress(src, *dst, s_len, d_len, complevel);
 156
 157         if (c_len > d_len)
 158                 return (s_len);
 159
 160         return (c_len);
 161 }
 162
 163 int
 164 zio_decompress_data(enum zio_compress c, abd_t *src, abd_t *dst,
 165     size_t s_len, size_t d_len, uint8_t *level)
 166 {
 167         zio_compress_info_t *ci = &zio_compress_table[c];
 168         if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
 169                 return (SET_ERROR(EINVAL));
 170
 171         int err;
 172         if (ci->ci_decompress_level != NULL && level != NULL)
 173                 err = ci->ci_decompress_level(src, dst, s_len, d_len, level);
 174         else
 175                 err = ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level);
 176
 177         /*
 178          * Decompression shouldn't fail, because we've already verified
 179          * the checksum.  However, for extra protection (e.g. against bitflips
 180          * in non-ECC RAM), we handle this error (and test it).
 181          */
 182         if (zio_decompress_fail_fraction != 0 &&
 183             random_in_range(zio_decompress_fail_fraction) == 0)
 184                 err = SET_ERROR(EINVAL);
 185
 186         return (err);
 187 }
 188
 189 int
 190 zio_compress_to_feature(enum zio_compress comp)
 191 {
 192         switch (comp) {
 193         case ZIO_COMPRESS_ZSTD:
 194                 return (SPA_FEATURE_ZSTD_COMPRESS);
 195         default:
 196                 break;
 197         }
 198         return (SPA_FEATURE_NONE);
 199 }