9759c60f1a
3035 LZ4 compression support in ZFS and GRUB Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Christopher Siden <christopher.siden@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Approved by: Christopher Siden <csiden@delphix.com> References: illumos/illumos-gate@a6f561b4ae https://www.illumos.org/issues/3035 http://wiki.illumos.org/display/illumos/LZ4+Compression+In+ZFS This patch has been slightly modified from the upstream Illumos version to be compatible with Linux. Due to the very limited stack space in the kernel a lz4 workspace kmem cache is used. Since we are using gcc we are also able to take advantage of the gcc optimized __builtin_ctz functions. Support for GRUB has been dropped from this patch. That code is available but those changes will need to made to the upstream GRUB package. Lastly, several hunks of dead code were dropped for clarity. They include the functions real_LZ4_uncompress(), LZ4_compressBound() and the Visual Studio specific hunks wrapped in _MSC_VER. Ported-by: Eric Dillmann <eric@jave.fr> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1217
137 lines
3.8 KiB
C
137 lines
3.8 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
|
|
#include <sys/zfs_context.h>
|
|
#include <sys/compress.h>
|
|
#include <sys/spa.h>
|
|
#include <sys/zio.h>
|
|
#include <sys/zio_compress.h>
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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);
|
|
|
|
/*
|
|
* 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)
|
|
return (0);
|
|
|
|
if (c == ZIO_COMPRESS_EMPTY)
|
|
return (s_len);
|
|
|
|
/* Compress at least 12.5% */
|
|
d_len = P2ALIGN(s_len - (s_len >> 3), (size_t)SPA_MINBLOCKSIZE);
|
|
if (d_len == 0)
|
|
return (s_len);
|
|
|
|
c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level);
|
|
|
|
if (c_len > d_len)
|
|
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, (size_t)SPA_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, (size_t)SPA_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 (EINVAL);
|
|
|
|
return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
|
|
}
|