From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001
From: Srikant Patnaik
Date: Sun, 11 Jan 2015 12:28:04 +0530
Subject: Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
---
 fs/cramfs/uncompress.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 fs/cramfs/uncompress.c

(limited to 'fs/cramfs/uncompress.c')

diff --git a/fs/cramfs/uncompress.c b/fs/cramfs/uncompress.c
new file mode 100644
index 00000000..02332980
--- /dev/null
+++ b/fs/cramfs/uncompress.c
@@ -0,0 +1,77 @@
+/*
+ * 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>
+#include <linux/cramfs_fs.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 -EIO;
+}
+
+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;
+}
+
+void cramfs_uncompress_exit(void)
+{
+	if (!--initialized) {
+		zlib_inflateEnd(&stream);
+		vfree(stream.workspace);
+	}
+}
-- 
cgit