mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-12 05:24:12 +08:00
5db53f3e80
This is a new flash file system. See Documentation/filesystems/logfs.txt Signed-off-by: Joern Engel <joern@logfs.org>
96 lines
1.8 KiB
C
96 lines
1.8 KiB
C
/*
|
|
* fs/logfs/compr.c - compression routines
|
|
*
|
|
* As should be obvious for Linux kernel code, license is GPLv2
|
|
*
|
|
* Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
|
|
*/
|
|
#include "logfs.h"
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/zlib.h>
|
|
|
|
#define COMPR_LEVEL 3
|
|
|
|
static DEFINE_MUTEX(compr_mutex);
|
|
static struct z_stream_s stream;
|
|
|
|
int logfs_compress(void *in, void *out, size_t inlen, size_t outlen)
|
|
{
|
|
int err, ret;
|
|
|
|
ret = -EIO;
|
|
mutex_lock(&compr_mutex);
|
|
err = zlib_deflateInit(&stream, COMPR_LEVEL);
|
|
if (err != Z_OK)
|
|
goto error;
|
|
|
|
stream.next_in = in;
|
|
stream.avail_in = inlen;
|
|
stream.total_in = 0;
|
|
stream.next_out = out;
|
|
stream.avail_out = outlen;
|
|
stream.total_out = 0;
|
|
|
|
err = zlib_deflate(&stream, Z_FINISH);
|
|
if (err != Z_STREAM_END)
|
|
goto error;
|
|
|
|
err = zlib_deflateEnd(&stream);
|
|
if (err != Z_OK)
|
|
goto error;
|
|
|
|
if (stream.total_out >= stream.total_in)
|
|
goto error;
|
|
|
|
ret = stream.total_out;
|
|
error:
|
|
mutex_unlock(&compr_mutex);
|
|
return ret;
|
|
}
|
|
|
|
int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen)
|
|
{
|
|
int err, ret;
|
|
|
|
ret = -EIO;
|
|
mutex_lock(&compr_mutex);
|
|
err = zlib_inflateInit(&stream);
|
|
if (err != Z_OK)
|
|
goto error;
|
|
|
|
stream.next_in = in;
|
|
stream.avail_in = inlen;
|
|
stream.total_in = 0;
|
|
stream.next_out = out;
|
|
stream.avail_out = outlen;
|
|
stream.total_out = 0;
|
|
|
|
err = zlib_inflate(&stream, Z_FINISH);
|
|
if (err != Z_STREAM_END)
|
|
goto error;
|
|
|
|
err = zlib_inflateEnd(&stream);
|
|
if (err != Z_OK)
|
|
goto error;
|
|
|
|
ret = 0;
|
|
error:
|
|
mutex_unlock(&compr_mutex);
|
|
return ret;
|
|
}
|
|
|
|
int __init logfs_compr_init(void)
|
|
{
|
|
size_t size = max(zlib_deflate_workspacesize(),
|
|
zlib_inflate_workspacesize());
|
|
stream.workspace = vmalloc(size);
|
|
if (!stream.workspace)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
void logfs_compr_exit(void)
|
|
{
|
|
vfree(stream.workspace);
|
|
}
|