summaryrefslogtreecommitdiffstats
path: root/fs/jffs2/compr_zlib.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/jffs2/compr_zlib.c')
-rw-r--r--fs/jffs2/compr_zlib.c218
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 0000000..9f9932c
--- /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();
+}
OpenPOWER on IntegriCloud