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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 by Delphix. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/compress.h>
#include <sys/kstat.h>
#include <sys/spa.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_minblocksize;
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_minblocksize", 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;
/*
* Compression vectors.
*/
zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
{NULL, NULL, 0, "inherit"},
{NULL, NULL, 0, "on"},
{NULL, NULL, 0, "uncompressed"},
{lzjb_compress, lzjb_decompress, 0, "lzjb"},
{NULL, NULL, 0, "empty"},
{gzip_compress, gzip_decompress, 1, "gzip-1"},
{gzip_compress, gzip_decompress, 2, "gzip-2"},
{gzip_compress, gzip_decompress, 3, "gzip-3"},
{gzip_compress, gzip_decompress, 4, "gzip-4"},
{gzip_compress, gzip_decompress, 5, "gzip-5"},
{gzip_compress, gzip_decompress, 6, "gzip-6"},
{gzip_compress, gzip_decompress, 7, "gzip-7"},
{gzip_compress, gzip_decompress, 8, "gzip-8"},
{gzip_compress, gzip_decompress, 9, "gzip-9"},
{zle_compress, zle_decompress, 64, "zle"},
{lz4_compress, lz4_decompress, 0, "lz4"},
};
enum zio_compress
zio_compress_select(enum zio_compress child, enum zio_compress parent)
{
ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON);
if (child == ZIO_COMPRESS_INHERIT)
return (parent);
if (child == ZIO_COMPRESS_ON)
return (ZIO_COMPRESS_ON_VALUE);
return (child);
}
size_t
zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len,
size_t minblocksize)
{
uint64_t *word, *word_end;
size_t c_len, d_len, r_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.
*/
word_end = (uint64_t *)((char *)src + s_len);
for (word = src; word < word_end; word++)
if (*word != 0)
break;
if (word == word_end) {
ZCOMPSTAT_BUMP(zcompstat_empty);
return (0);
}
if (c == ZIO_COMPRESS_EMPTY)
return (s_len);
/* Compress at least 12.5% */
d_len = P2ALIGN(s_len - (s_len >> 3), minblocksize);
if (d_len == 0) {
ZCOMPSTAT_BUMP(zcompstat_skipped_minblocksize);
return (s_len);
}
c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level);
if (c_len > d_len) {
ZCOMPSTAT_BUMP(zcompstat_skipped_insufficient_gain);
return (s_len);
}
/*
* Cool. We compressed at least as much as we were hoping to.
* For both security and repeatability, pad out the last sector.
*/
r_len = P2ROUNDUP(c_len, minblocksize);
if (r_len > c_len) {
bzero((char *)dst + c_len, r_len - c_len);
c_len = r_len;
}
ASSERT3U(c_len, <=, d_len);
ASSERT(P2PHASE(c_len, minblocksize) == 0);
return (c_len);
}
int
zio_decompress_data(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));
}
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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