dc8a0843a4
deflate_mutex protects the globals lzo_mem and lzo_compress_buf. However, jffs2_lzo_compress() unlocks deflate_mutex _before_ it has copied out the compressed data from lzo_compress_buf. Correct this by moving the mutex unlock after the copy. In addition, document what deflate_mutex actually protects. Cc: stable@kernel.org Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-by: Richard Purdie <rpurdie@openedhand.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
112 lines
2.3 KiB
C
112 lines
2.3 KiB
C
/*
|
|
* JFFS2 -- Journalling Flash File System, Version 2.
|
|
*
|
|
* Copyright © 2007 Nokia Corporation. All rights reserved.
|
|
*
|
|
* Created by Richard Purdie <rpurdie@openedhand.com>
|
|
*
|
|
* For licensing information, see the file 'LICENCE' in this directory.
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/init.h>
|
|
#include <linux/lzo.h>
|
|
#include "compr.h"
|
|
|
|
static void *lzo_mem;
|
|
static void *lzo_compress_buf;
|
|
static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */
|
|
|
|
static void free_workspace(void)
|
|
{
|
|
vfree(lzo_mem);
|
|
vfree(lzo_compress_buf);
|
|
}
|
|
|
|
static int __init alloc_workspace(void)
|
|
{
|
|
lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
|
|
lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
|
|
|
|
if (!lzo_mem || !lzo_compress_buf) {
|
|
printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n");
|
|
free_workspace();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
|
|
uint32_t *sourcelen, uint32_t *dstlen, void *model)
|
|
{
|
|
size_t compress_size;
|
|
int ret;
|
|
|
|
mutex_lock(&deflate_mutex);
|
|
ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
|
|
if (ret != LZO_E_OK)
|
|
goto fail;
|
|
|
|
if (compress_size > *dstlen)
|
|
goto fail;
|
|
|
|
memcpy(cpage_out, lzo_compress_buf, compress_size);
|
|
mutex_unlock(&deflate_mutex);
|
|
|
|
*dstlen = compress_size;
|
|
return 0;
|
|
|
|
fail:
|
|
mutex_unlock(&deflate_mutex);
|
|
return -1;
|
|
}
|
|
|
|
static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
|
|
uint32_t srclen, uint32_t destlen, void *model)
|
|
{
|
|
size_t dl = destlen;
|
|
int ret;
|
|
|
|
ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
|
|
|
|
if (ret != LZO_E_OK || dl != destlen)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct jffs2_compressor jffs2_lzo_comp = {
|
|
.priority = JFFS2_LZO_PRIORITY,
|
|
.name = "lzo",
|
|
.compr = JFFS2_COMPR_LZO,
|
|
.compress = &jffs2_lzo_compress,
|
|
.decompress = &jffs2_lzo_decompress,
|
|
.disabled = 0,
|
|
};
|
|
|
|
int __init jffs2_lzo_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = alloc_workspace();
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = jffs2_register_compressor(&jffs2_lzo_comp);
|
|
if (ret)
|
|
free_workspace();
|
|
|
|
return ret;
|
|
}
|
|
|
|
void jffs2_lzo_exit(void)
|
|
{
|
|
jffs2_unregister_compressor(&jffs2_lzo_comp);
|
|
free_workspace();
|
|
}
|