kernel-ark/fs/cramfs/uncompress.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

78 lines
1.7 KiB
C

/*
* uncompress.c
*
* (C) Copyright 1999 Linus Torvalds
*
* cramfs interfaces to the uncompression library. There's really just
* three entrypoints:
*
* - cramfs_uncompress_init() - called to initialize the thing.
* - cramfs_uncompress_exit() - tell me when you're done
* - cramfs_uncompress_block() - uncompress a block.
*
* NOTE NOTE NOTE! The uncompression is entirely single-threaded. We
* only have one stream, and we'll initialize it only once even if it
* then is used by multiple filesystems.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/vmalloc.h>
#include <linux/zlib.h>
static z_stream stream;
static int initialized;
/* Returns length of decompressed data. */
int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen)
{
int err;
stream.next_in = src;
stream.avail_in = srclen;
stream.next_out = dst;
stream.avail_out = dstlen;
err = zlib_inflateReset(&stream);
if (err != Z_OK) {
printk("zlib_inflateReset error %d\n", err);
zlib_inflateEnd(&stream);
zlib_inflateInit(&stream);
}
err = zlib_inflate(&stream, Z_FINISH);
if (err != Z_STREAM_END)
goto err;
return stream.total_out;
err:
printk("Error %d while decompressing!\n", err);
printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);
return 0;
}
int cramfs_uncompress_init(void)
{
if (!initialized++) {
stream.workspace = vmalloc(zlib_inflate_workspacesize());
if ( !stream.workspace ) {
initialized = 0;
return -ENOMEM;
}
stream.next_in = NULL;
stream.avail_in = 0;
zlib_inflateInit(&stream);
}
return 0;
}
int cramfs_uncompress_exit(void)
{
if (!--initialized) {
zlib_inflateEnd(&stream);
vfree(stream.workspace);
}
return 0;
}