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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/squashfs/zlib_wrapper.c
Initial import
Diffstat (limited to 'fs/squashfs/zlib_wrapper.c')
-rw-r--r--fs/squashfs/zlib_wrapper.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 000000000..8727caba6
--- /dev/null
+++ b/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
+};
+