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/*
* Copyright (C) 2014 Sergey Senozhatsky.
*
* This program 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.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/lzo.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include "zcomp_lzo.h"
static void *lzo_create(void)
{
void *ret;
/*
* This function can be called in swapout/fs write path
* so we can't use GFP_FS|IO. And it assumes we already
* have at least one stream in zram initialization so we
* don't do best effort to allocate more stream in here.
* A default stream will work well without further multiple
* streams. That's why we use NORETRY | NOWARN.
*/
ret = kzalloc(LZO1X_MEM_COMPRESS, GFP_NOIO | __GFP_NORETRY |
__GFP_NOWARN);
if (!ret)
ret = __vmalloc(LZO1X_MEM_COMPRESS,
GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN |
__GFP_ZERO | __GFP_HIGHMEM,
PAGE_KERNEL);
return ret;
}
static void lzo_destroy(void *private)
{
kvfree(private);
}
static int lzo_compress(const unsigned char *src, unsigned char *dst,
size_t *dst_len, void *private)
{
int ret = lzo1x_1_compress(src, PAGE_SIZE, dst, dst_len, private);
return ret == LZO_E_OK ? 0 : ret;
}
static int lzo_decompress(const unsigned char *src, size_t src_len,
unsigned char *dst)
{
size_t dst_len = PAGE_SIZE;
int ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
return ret == LZO_E_OK ? 0 : ret;
}
struct zcomp_backend zcomp_lzo = {
.compress = lzo_compress,
.decompress = lzo_decompress,
.create = lzo_create,
.destroy = lzo_destroy,
.name = "lzo",
};
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