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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
* Copyright (c) 2013, 2018 by Delphix. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/compress.h>
#include <sys/kstat.h>
#include <sys/spa.h>
#include <sys/zfeature.h>
#include <sys/zio.h>
#include <sys/zio_compress.h>
typedef struct zcomp_stats {
kstat_named_t zcompstat_attempts;
kstat_named_t zcompstat_empty;
kstat_named_t zcompstat_skipped_insufficient_gain;
} zcomp_stats_t;
static zcomp_stats_t zcomp_stats = {
{ "attempts", KSTAT_DATA_UINT64 },
{ "empty", KSTAT_DATA_UINT64 },
{ "skipped_insufficient_gain", KSTAT_DATA_UINT64 }
};
#define ZCOMPSTAT_INCR(stat, val) \
atomic_add_64(&zcomp_stats.stat.value.ui64, (val));
#define ZCOMPSTAT_BUMP(stat) ZCOMPSTAT_INCR(stat, 1);
kstat_t *zcomp_ksp;
/*
* If nonzero, every 1/X decompression attempts will fail, simulating
* an undetected memory error.
*/
uint64_t zio_decompress_fail_fraction = 0;
/*
* Compression vectors.
*/
zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
{"inherit", 0, NULL, NULL},
{"on", 0, NULL, NULL},
{"uncompressed", 0, NULL, NULL},
{"lzjb", 0, lzjb_compress, lzjb_decompress},
{"empty", 0, NULL, NULL},
{"gzip-1", 1, gzip_compress, gzip_decompress},
{"gzip-2", 2, gzip_compress, gzip_decompress},
{"gzip-3", 3, gzip_compress, gzip_decompress},
{"gzip-4", 4, gzip_compress, gzip_decompress},
{"gzip-5", 5, gzip_compress, gzip_decompress},
{"gzip-6", 6, gzip_compress, gzip_decompress},
{"gzip-7", 7, gzip_compress, gzip_decompress},
{"gzip-8", 8, gzip_compress, gzip_decompress},
{"gzip-9", 9, gzip_compress, gzip_decompress},
{"zle", 64, zle_compress, zle_decompress},
{"lz4", 0, lz4_compress, lz4_decompress}
};
enum zio_compress
zio_compress_select(spa_t *spa, enum zio_compress child,
enum zio_compress parent)
{
enum zio_compress result;
ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
ASSERT(parent != ZIO_COMPRESS_INHERIT);
result = child;
if (result == ZIO_COMPRESS_INHERIT)
result = parent;
if (result == ZIO_COMPRESS_ON) {
if (spa_feature_is_active(spa, SPA_FEATURE_LZ4_COMPRESS))
result = ZIO_COMPRESS_LZ4_ON_VALUE;
else
result = ZIO_COMPRESS_LEGACY_ON_VALUE;
}
return (result);
}
/*ARGSUSED*/
static int
zio_compress_zeroed_cb(void *data, size_t len, void *private)
{
uint64_t *end = (uint64_t *)((char *)data + len);
for (uint64_t *word = (uint64_t *)data; word < end; word++)
if (*word != 0)
return (1);
return (0);
}
size_t
zio_compress_data(enum zio_compress c, abd_t *src, void *dst, size_t s_len)
{
size_t c_len, d_len;
zio_compress_info_t *ci = &zio_compress_table[c];
ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
ZCOMPSTAT_BUMP(zcompstat_attempts);
/*
* If the data is all zeroes, we don't even need to allocate
* a block for it. We indicate this by returning zero size.
*/
if (abd_iterate_func(src, 0, s_len, zio_compress_zeroed_cb, NULL) == 0) {
ZCOMPSTAT_BUMP(zcompstat_empty);
return (0);
}
if (c == ZIO_COMPRESS_EMPTY)
return (s_len);
/* Compress at least 12.5% */
d_len = s_len - (s_len >> 3);
/* No compression algorithms can read from ABDs directly */
void *tmp = abd_borrow_buf_copy(src, s_len);
c_len = ci->ci_compress(tmp, dst, s_len, d_len, ci->ci_level);
abd_return_buf(src, tmp, s_len);
if (c_len > d_len) {
ZCOMPSTAT_BUMP(zcompstat_skipped_insufficient_gain);
return (s_len);
}
ASSERT3U(c_len, <=, d_len);
return (c_len);
}
int
zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
size_t s_len, size_t d_len)
{
zio_compress_info_t *ci = &zio_compress_table[c];
if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
return (SET_ERROR(EINVAL));
return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
}
int
zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
size_t s_len, size_t d_len)
{
void *tmp = abd_borrow_buf_copy(src, s_len);
int ret = zio_decompress_data_buf(c, tmp, dst, s_len, d_len);
abd_return_buf(src, tmp, s_len);
/*
* Decompression shouldn't fail, because we've already verifyied
* the checksum. However, for extra protection (e.g. against bitflips
* in non-ECC RAM), we handle this error (and test it).
*/
ASSERT0(ret);
if (zio_decompress_fail_fraction != 0 &&
spa_get_random(zio_decompress_fail_fraction) == 0)
ret = SET_ERROR(EINVAL);
return (ret);
}
void
zio_compress_init(void)
{
zcomp_ksp = kstat_create("zfs", 0, "zcompstats", "misc",
KSTAT_TYPE_NAMED, sizeof (zcomp_stats) / sizeof (kstat_named_t),
KSTAT_FLAG_VIRTUAL);
if (zcomp_ksp != NULL) {
zcomp_ksp->ks_data = &zcomp_stats;
kstat_install(zcomp_ksp);
}
}
void
zio_compress_fini(void)
{
if (zcomp_ksp != NULL) {
kstat_delete(zcomp_ksp);
zcomp_ksp = NULL;
}
}
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