--- /dev/null
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#if !defined(__KERNEL__) && !defined(__ECOS)
+#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
+#endif
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/zlib.h>
+#include <linux/zutil.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 DEFINE_MUTEX(deflate_mutex);
+static DEFINE_MUTEX(inflate_mutex);
+static z_stream inf_strm, def_strm;
+
+#ifdef __KERNEL__ /* Linux-only */
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+
+static int __init alloc_workspaces(void)
+{
+ def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS,
+ MAX_MEM_LEVEL));
+ if (!def_strm.workspace)
+ return -ENOMEM;
+
+ jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n",
+ zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL));
+ inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
+ if (!inf_strm.workspace) {
+ vfree(def_strm.workspace);
+ return -ENOMEM;
+ }
+ jffs2_dbg(1, "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__ */
+
+static int jffs2_zlib_compress(unsigned char *data_in,
+ unsigned char *cpage_out,
+ uint32_t *sourcelen, uint32_t *dstlen)
+{
+ int ret;
+
+ if (*dstlen <= STREAM_END_SPACE)
+ return -1;
+
+ mutex_lock(&deflate_mutex);
+
+ if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
+ pr_warn("deflateInit failed\n");
+ mutex_unlock(&deflate_mutex);
+ 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_t(unsigned long,
+ (*sourcelen-def_strm.total_in), def_strm.avail_out);
+ jffs2_dbg(1, "calling deflate with avail_in %ld, avail_out %ld\n",
+ def_strm.avail_in, def_strm.avail_out);
+ ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
+ jffs2_dbg(1, "deflate returned with avail_in %ld, avail_out %ld, 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) {
+ jffs2_dbg(1, "deflate in loop returned %d\n", ret);
+ zlib_deflateEnd(&def_strm);
+ mutex_unlock(&deflate_mutex);
+ 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) {
+ jffs2_dbg(1, "final deflate returned %d\n", ret);
+ ret = -1;
+ goto out;
+ }
+
+ if (def_strm.total_out >= def_strm.total_in) {
+ jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n",
+ def_strm.total_in, def_strm.total_out);
+ ret = -1;
+ goto out;
+ }
+
+ jffs2_dbg(1, "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:
+ mutex_unlock(&deflate_mutex);
+ return ret;
+}
+
+static int jffs2_zlib_decompress(unsigned char *data_in,
+ unsigned char *cpage_out,
+ uint32_t srclen, uint32_t destlen)
+{
+ int ret;
+ int wbits = MAX_WBITS;
+
+ mutex_lock(&inflate_mutex);
+
+ 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)) {
+
+ jffs2_dbg(2, "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 */
+ jffs2_dbg(1, "inflate not skipping adler32\n");
+ }
+
+
+ if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
+ pr_warn("inflateInit failed\n");
+ mutex_unlock(&inflate_mutex);
+ return 1;
+ }
+
+ while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
+ ;
+ if (ret != Z_STREAM_END) {
+ pr_notice("inflate returned %d\n", ret);
+ }
+ zlib_inflateEnd(&inf_strm);
+ mutex_unlock(&inflate_mutex);
+ 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();
+}
Code Review / kvmfornfv.git / blobdiff