Add the rt linux 4.1.3-rt3 as base

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

diff --git a/kernel/fs/squashfs/xz_wrapper.c b/kernel/fs/squashfs/xz_wrapper.c
new file mode 100644 (file)
index 0000000..c609624
--- /dev/null
+++ b/kernel/fs/squashfs/xz_wrapper.c
@@ -0,0 +1,193 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ * 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.
+ *
+ * xz_wrapper.c
+ */
+
+
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/xz.h>
+#include <linux/bitops.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs.h"
+#include "decompressor.h"
+#include "page_actor.h"
+
+struct squashfs_xz {
+       struct xz_dec *state;
+       struct xz_buf buf;
+};
+
+struct disk_comp_opts {
+       __le32 dictionary_size;
+       __le32 flags;
+};
+
+struct comp_opts {
+       int dict_size;
+};
+
+static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk,
+       void *buff, int len)
+{
+       struct disk_comp_opts *comp_opts = buff;
+       struct comp_opts *opts;
+       int err = 0, n;
+
+       opts = kmalloc(sizeof(*opts), GFP_KERNEL);
+       if (opts == NULL) {
+               err = -ENOMEM;
+               goto out2;
+       }
+
+       if (comp_opts) {
+               /* check compressor options are the expected length */
+               if (len < sizeof(*comp_opts)) {
+                       err = -EIO;
+                       goto out;
+               }
+
+               opts->dict_size = le32_to_cpu(comp_opts->dictionary_size);
+
+               /* the dictionary size should be 2^n or 2^n+2^(n+1) */
+               n = ffs(opts->dict_size) - 1;
+               if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) +
+                                               (1 << (n + 1))) {
+                       err = -EIO;
+                       goto out;
+               }
+       } else
+               /* use defaults */
+               opts->dict_size = max_t(int, msblk->block_size,
+                                                       SQUASHFS_METADATA_SIZE);
+
+       return opts;
+
+out:
+       kfree(opts);
+out2:
+       return ERR_PTR(err);
+}
+
+
+static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff)
+{
+       struct comp_opts *comp_opts = buff;
+       struct squashfs_xz *stream;
+       int err;
+
+       stream = kmalloc(sizeof(*stream), GFP_KERNEL);
+       if (stream == NULL) {
+               err = -ENOMEM;
+               goto failed;
+       }
+
+       stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size);
+       if (stream->state == NULL) {
+               kfree(stream);
+               err = -ENOMEM;
+               goto failed;
+       }
+
+       return stream;
+
+failed:
+       ERROR("Failed to initialise xz decompressor\n");
+       return ERR_PTR(err);
+}
+
+
+static void squashfs_xz_free(void *strm)
+{
+       struct squashfs_xz *stream = strm;
+
+       if (stream) {
+               xz_dec_end(stream->state);
+               kfree(stream);
+       }
+}
+
+
+static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
+       struct buffer_head **bh, int b, int offset, int length,
+       struct squashfs_page_actor *output)
+{
+       enum xz_ret xz_err;
+       int avail, total = 0, k = 0;
+       struct squashfs_xz *stream = strm;
+
+       xz_dec_reset(stream->state);
+       stream->buf.in_pos = 0;
+       stream->buf.in_size = 0;
+       stream->buf.out_pos = 0;
+       stream->buf.out_size = PAGE_CACHE_SIZE;
+       stream->buf.out = squashfs_first_page(output);
+
+       do {
+               if (stream->buf.in_pos == stream->buf.in_size && k < b) {
+                       avail = min(length, msblk->devblksize - offset);
+                       length -= avail;
+                       stream->buf.in = bh[k]->b_data + offset;
+                       stream->buf.in_size = avail;
+                       stream->buf.in_pos = 0;
+                       offset = 0;
+               }
+
+               if (stream->buf.out_pos == stream->buf.out_size) {
+                       stream->buf.out = squashfs_next_page(output);
+                       if (stream->buf.out != NULL) {
+                               stream->buf.out_pos = 0;
+                               total += PAGE_CACHE_SIZE;
+                       }
+               }
+
+               xz_err = xz_dec_run(stream->state, &stream->buf);
+
+               if (stream->buf.in_pos == stream->buf.in_size && k < b)
+                       put_bh(bh[k++]);
+       } while (xz_err == XZ_OK);
+
+       squashfs_finish_page(output);
+
+       if (xz_err != XZ_STREAM_END || k < b)
+               goto out;
+
+       return total + stream->buf.out_pos;
+
+out:
+       for (; k < b; k++)
+               put_bh(bh[k]);
+
+       return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_xz_comp_ops = {
+       .init = squashfs_xz_init,
+       .comp_opts = squashfs_xz_comp_opts,
+       .free = squashfs_xz_free,
+       .decompress = squashfs_xz_uncompress,
+       .id = XZ_COMPRESSION,
+       .name = "xz",
+       .supported = 1
+};