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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/cramfs/uncompress.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-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!
Diffstat (limited to 'fs/cramfs/uncompress.c')
-rw-r--r--fs/cramfs/uncompress.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/fs/cramfs/uncompress.c b/fs/cramfs/uncompress.c
new file mode 100644
index 00000000000..5034365b06a
--- /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>
+
+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;
+}