Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / squashfs / zlib_wrapper.c

diff --git a/kernel/fs/squashfs/zlib_wrapper.c b/kernel/fs/squashfs/zlib_wrapper.c
new file mode 100644 (file)
index 0000000..8727cab
--- /dev/null
+++ b/kernel/fs/squashfs/zlib_wrapper.c
@@ -0,0 +1,135 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * zlib_wrapper.c
+ */
+
+
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/zlib.h>
+#include <linux/vmalloc.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs.h"
+#include "decompressor.h"
+#include "page_actor.h"
+
+static void *zlib_init(struct squashfs_sb_info *dummy, void *buff)
+{
+       z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
+       if (stream == NULL)
+               goto failed;
+       stream->workspace = vmalloc(zlib_inflate_workspacesize());
+       if (stream->workspace == NULL)
+               goto failed;
+
+       return stream;
+
+failed:
+       ERROR("Failed to allocate zlib workspace\n");
+       kfree(stream);
+       return ERR_PTR(-ENOMEM);
+}
+
+
+static void zlib_free(void *strm)
+{
+       z_stream *stream = strm;
+
+       if (stream)
+               vfree(stream->workspace);
+       kfree(stream);
+}
+
+
+static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
+       struct buffer_head **bh, int b, int offset, int length,
+       struct squashfs_page_actor *output)
+{
+       int zlib_err, zlib_init = 0, k = 0;
+       z_stream *stream = strm;
+
+       stream->avail_out = PAGE_CACHE_SIZE;
+       stream->next_out = squashfs_first_page(output);
+       stream->avail_in = 0;
+
+       do {
+               if (stream->avail_in == 0 && k < b) {
+                       int avail = min(length, msblk->devblksize - offset);
+                       length -= avail;
+                       stream->next_in = bh[k]->b_data + offset;
+                       stream->avail_in = avail;
+                       offset = 0;
+               }
+
+               if (stream->avail_out == 0) {
+                       stream->next_out = squashfs_next_page(output);
+                       if (stream->next_out != NULL)
+                               stream->avail_out = PAGE_CACHE_SIZE;
+               }
+
+               if (!zlib_init) {
+                       zlib_err = zlib_inflateInit(stream);
+                       if (zlib_err != Z_OK) {
+                               squashfs_finish_page(output);
+                               goto out;
+                       }
+                       zlib_init = 1;
+               }
+
+               zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
+
+               if (stream->avail_in == 0 && k < b)
+                       put_bh(bh[k++]);
+       } while (zlib_err == Z_OK);
+
+       squashfs_finish_page(output);
+
+       if (zlib_err != Z_STREAM_END)
+               goto out;
+
+       zlib_err = zlib_inflateEnd(stream);
+       if (zlib_err != Z_OK)
+               goto out;
+
+       if (k < b)
+               goto out;
+
+       return stream->total_out;
+
+out:
+       for (; k < b; k++)
+               put_bh(bh[k]);
+
+       return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_zlib_comp_ops = {
+       .init = zlib_init,
+       .free = zlib_free,
+       .decompress = zlib_uncompress,
+       .id = ZLIB_COMPRESSION,
+       .name = "zlib",
+       .supported = 1
+};
+