1 files changed, 218 insertions, 0 deletions
diff --git a/fs/jffs2/compr_zlib.c b/fs/jffs2/compr_zlib.c
new file mode 100644
index 000000000000..9f9932c22adb
--- /dev/null
+++ b/fs/jffs2/compr_zlib.c
@@ -0,0 +1,218 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2001-2003 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ * $Id: compr_zlib.c,v 1.29 2004/11/16 20:36:11 dwmw2 Exp $
+ *
+ */
+
+#if !defined(__KERNEL__) && !defined(__ECOS)
+#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
+#endif
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/zlib.h>
+#include <linux/zutil.h>
+#include <asm/semaphore.h>
+#include "nodelist.h"
+#include "compr.h"
+
+	/* Plan: call deflate() with avail_in == *sourcelen, 
+		avail_out = *dstlen - 12 and flush == Z_FINISH. 
+		If it doesn't manage to finish,	call it again with
+		avail_in == 0 and avail_out set to the remaining 12
+		bytes for it to clean up. 
+	   Q: Is 12 bytes sufficient?
+	*/
+#define STREAM_END_SPACE 12
+
+static DECLARE_MUTEX(deflate_sem);
+static DECLARE_MUTEX(inflate_sem);
+static z_stream inf_strm, def_strm;
+
+#ifdef __KERNEL__ /* Linux-only */
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+
+static int __init alloc_workspaces(void)
+{
+	def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
+	if (!def_strm.workspace) {
+		printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize());
+		return -ENOMEM;
+	}
+	D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize()));
+	inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
+	if (!inf_strm.workspace) {
+		printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize());
+		vfree(def_strm.workspace);
+		return -ENOMEM;
+	}
+	D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
+	return 0;
+}
+
+static void free_workspaces(void)
+{
+	vfree(def_strm.workspace);
+	vfree(inf_strm.workspace);
+}
+#else
+#define alloc_workspaces() (0)
+#define free_workspaces() do { } while(0)
+#endif /* __KERNEL__ */
+
+int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out, 
+		   uint32_t *sourcelen, uint32_t *dstlen, void *model)
+{
+	int ret;
+
+	if (*dstlen <= STREAM_END_SPACE)
+		return -1;
+
+	down(&deflate_sem);
+
+	if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
+		printk(KERN_WARNING "deflateInit failed\n");
+		up(&deflate_sem);
+		return -1;
+	}
+
+	def_strm.next_in = data_in;
+	def_strm.total_in = 0;
+	
+	def_strm.next_out = cpage_out;
+	def_strm.total_out = 0;
+
+	while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) {
+		def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
+		def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
+		D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n",
+			  def_strm.avail_in, def_strm.avail_out));
+		ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
+		D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 
+			  def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out));
+		if (ret != Z_OK) {
+			D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
+			zlib_deflateEnd(&def_strm);
+			up(&deflate_sem);
+			return -1;
+		}
+	}
+	def_strm.avail_out += STREAM_END_SPACE;
+	def_strm.avail_in = 0;
+	ret = zlib_deflate(&def_strm, Z_FINISH);
+	zlib_deflateEnd(&def_strm);
+
+	if (ret != Z_STREAM_END) {
+		D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
+		ret = -1;
+		goto out;
+	}
+
+	if (def_strm.total_out >= def_strm.total_in) {
+		D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n",
+			  def_strm.total_in, def_strm.total_out));
+		ret = -1;
+		goto out;
+	}
+
+	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
+		  def_strm.total_in, def_strm.total_out));
+
+	*dstlen = def_strm.total_out;
+	*sourcelen = def_strm.total_in;
+	ret = 0;
+ out:
+	up(&deflate_sem);
+	return ret;
+}
+
+int jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out,
+		      uint32_t srclen, uint32_t destlen, void *model)
+{
+	int ret;
+	int wbits = MAX_WBITS;
+
+	down(&inflate_sem);
+
+	inf_strm.next_in = data_in;
+	inf_strm.avail_in = srclen;
+	inf_strm.total_in = 0;
+	
+	inf_strm.next_out = cpage_out;
+	inf_strm.avail_out = destlen;
+	inf_strm.total_out = 0;
+
+	/* If it's deflate, and it's got no preset dictionary, then
+	   we can tell zlib to skip the adler32 check. */
+	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
+	    ((data_in[0] & 0x0f) == Z_DEFLATED) &&
+	    !(((data_in[0]<<8) + data_in[1]) % 31)) {
+
+		D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
+		wbits = -((data_in[0] >> 4) + 8);
+		inf_strm.next_in += 2;
+		inf_strm.avail_in -= 2;
+	} else {
+		/* Let this remain D1 for now -- it should never happen */
+		D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
+	}
+
+
+	if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
+		printk(KERN_WARNING "inflateInit failed\n");
+		up(&inflate_sem);
+		return 1;
+	}
+
+	while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
+		;
+	if (ret != Z_STREAM_END) {
+		printk(KERN_NOTICE "inflate returned %d\n", ret);
+	}
+	zlib_inflateEnd(&inf_strm);
+	up(&inflate_sem);
+        return 0;
+}
+
+static struct jffs2_compressor jffs2_zlib_comp = {
+    .priority = JFFS2_ZLIB_PRIORITY,
+    .name = "zlib",
+    .compr = JFFS2_COMPR_ZLIB,
+    .compress = &jffs2_zlib_compress,
+    .decompress = &jffs2_zlib_decompress,
+#ifdef JFFS2_ZLIB_DISABLED
+    .disabled = 1,
+#else
+    .disabled = 0,
+#endif
+};
+
+int __init jffs2_zlib_init(void)
+{
+    int ret;
+
+    ret = alloc_workspaces();
+    if (ret)
+        return ret;
+
+    ret = jffs2_register_compressor(&jffs2_zlib_comp);
+    if (ret)
+        free_workspaces();
+
+    return ret;
+}
+
+void jffs2_zlib_exit(void)
+{
+    jffs2_unregister_compressor(&jffs2_zlib_comp);
+    free_workspaces();
+}