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/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************
* z_compress_level/z_uncompress are nearly identical copies of the
* compress2/uncompress functions provided by the official zlib package
* available at http://zlib.net/. The only changes made we to slightly
* adapt the functions called to match the linux kernel implementation
* of zlib. The full zlib license follows:
*
* zlib.h -- interface of the 'zlib' general purpose compression library
* version 1.2.5, April 19th, 2010
*
* Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* Jean-loup Gailly
* Mark Adler
\*****************************************************************************/
#include <sys/kmem.h>
#include <sys/zmod.h>
#include <linux/zlib_compat.h>
static spl_kmem_cache_t *zlib_workspace_cache;
/*
* A kmem_cache is used for the zlib workspaces to avoid having to vmalloc
* and vfree for every call. Using a kmem_cache also has the advantage
* that improves the odds that the memory used will be local to this cpu.
* To further improve things it might be wise to create a dedicated per-cpu
* workspace for use. This would take some additional care because we then
* must disable preemption around the critical section, and verify that
* zlib_deflate* and zlib_inflate* never internally call schedule().
*/
static void *
zlib_workspace_alloc(int flags)
{
return kmem_cache_alloc(zlib_workspace_cache, flags & ~(__GFP_FS));
}
static void
zlib_workspace_free(void *workspace)
{
kmem_cache_free(zlib_workspace_cache, workspace);
}
/*
* Compresses the source buffer into the destination buffer. The level
* parameter has the same meaning as in deflateInit. sourceLen is the byte
* length of the source buffer. Upon entry, destLen is the total size of the
* destination buffer, which must be at least 0.1% larger than sourceLen plus
* 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
*
* compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
* memory, Z_BUF_ERROR if there was not enough room in the output buffer,
* Z_STREAM_ERROR if the level parameter is invalid.
*/
int
z_compress_level(void *dest, size_t *destLen, const void *source,
size_t sourceLen, int level)
{
z_stream stream;
int err;
stream.next_in = (Byte *)source;
stream.avail_in = (uInt)sourceLen;
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((size_t)stream.avail_out != *destLen)
return Z_BUF_ERROR;
stream.workspace = zlib_workspace_alloc(KM_SLEEP);
if (!stream.workspace)
return Z_MEM_ERROR;
err = zlib_deflateInit(&stream, level);
if (err != Z_OK) {
zlib_workspace_free(stream.workspace);
return err;
}
err = zlib_deflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
zlib_deflateEnd(&stream);
zlib_workspace_free(stream.workspace);
return err == Z_OK ? Z_BUF_ERROR : err;
}
*destLen = stream.total_out;
err = zlib_deflateEnd(&stream);
zlib_workspace_free(stream.workspace);
return err;
}
EXPORT_SYMBOL(z_compress_level);
/*
* Decompresses the source buffer into the destination buffer. sourceLen is
* the byte length of the source buffer. Upon entry, destLen is the total
* size of the destination buffer, which must be large enough to hold the
* entire uncompressed data. (The size of the uncompressed data must have
* been saved previously by the compressor and transmitted to the decompressor
* by some mechanism outside the scope of this compression library.)
* Upon exit, destLen is the actual size of the compressed buffer.
* This function can be used to decompress a whole file at once if the
* input file is mmap'ed.
*
* uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
* enough memory, Z_BUF_ERROR if there was not enough room in the output
* buffer, or Z_DATA_ERROR if the input data was corrupted.
*/
int
z_uncompress(void *dest, size_t *destLen, const void *source, size_t sourceLen)
{
z_stream stream;
int err;
stream.next_in = (Byte *)source;
stream.avail_in = (uInt)sourceLen;
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((size_t)stream.avail_out != *destLen)
return Z_BUF_ERROR;
stream.workspace = zlib_workspace_alloc(KM_SLEEP);
if (!stream.workspace)
return Z_MEM_ERROR;
err = zlib_inflateInit(&stream);
if (err != Z_OK) {
zlib_workspace_free(stream.workspace);
return err;
}
err = zlib_inflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
zlib_inflateEnd(&stream);
zlib_workspace_free(stream.workspace);
if (err == Z_NEED_DICT ||
(err == Z_BUF_ERROR && stream.avail_in == 0))
return Z_DATA_ERROR;
return err;
}
*destLen = stream.total_out;
err = zlib_inflateEnd(&stream);
zlib_workspace_free(stream.workspace);
return err;
}
EXPORT_SYMBOL(z_uncompress);
int
spl_zlib_init(void)
{
int size;
size = MAX(spl_zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
zlib_inflate_workspacesize());
zlib_workspace_cache = kmem_cache_create(
"spl_zlib_workspace_cache",
size, 0, NULL, NULL, NULL, NULL, NULL,
KMC_VMEM | KMC_NOEMERGENCY);
if (!zlib_workspace_cache)
return (1);
return (0);
}
void
spl_zlib_fini(void)
{
kmem_cache_destroy(zlib_workspace_cache);
zlib_workspace_cache = NULL;
}
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