2 * Squashfs - a compressed read only filesystem for Linux
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
5 * Phillip Lougher <phillip@lougher.demon.co.uk>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2,
10 * or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25 #include <linux/mutex.h>
26 #include <linux/buffer_head.h>
27 #include <linux/slab.h>
30 #include "squashfs_fs.h"
31 #include "squashfs_fs_sb.h"
32 #include "squashfs_fs_i.h"
34 #include "decompressor.h"
41 static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
43 int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
45 struct squashfs_xz *stream = kmalloc(sizeof(*stream), GFP_KERNEL);
49 stream->state = xz_dec_init(XZ_PREALLOC, block_size);
50 if (stream->state == NULL)
56 ERROR("Failed to allocate xz workspace\n");
62 static void squashfs_xz_free(void *strm)
64 struct squashfs_xz *stream = strm;
67 xz_dec_end(stream->state);
73 static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void **buffer,
74 struct buffer_head **bh, int b, int offset, int length, int srclength,
78 int avail, total = 0, k = 0, page = 0;
79 struct squashfs_xz *stream = msblk->stream;
81 mutex_lock(&msblk->read_data_mutex);
83 xz_dec_reset(stream->state);
84 stream->buf.in_pos = 0;
85 stream->buf.in_size = 0;
86 stream->buf.out_pos = 0;
87 stream->buf.out_size = PAGE_CACHE_SIZE;
88 stream->buf.out = buffer[page++];
91 if (stream->buf.in_pos == stream->buf.in_size && k < b) {
92 avail = min(length, msblk->devblksize - offset);
94 wait_on_buffer(bh[k]);
95 if (!buffer_uptodate(bh[k]))
98 stream->buf.in = bh[k]->b_data + offset;
99 stream->buf.in_size = avail;
100 stream->buf.in_pos = 0;
104 if (stream->buf.out_pos == stream->buf.out_size
106 stream->buf.out = buffer[page++];
107 stream->buf.out_pos = 0;
108 total += PAGE_CACHE_SIZE;
111 xz_err = xz_dec_run(stream->state, &stream->buf);
113 if (stream->buf.in_pos == stream->buf.in_size && k < b)
115 } while (xz_err == XZ_OK);
117 if (xz_err != XZ_STREAM_END) {
118 ERROR("xz_dec_run error, data probably corrupt\n");
123 ERROR("xz_uncompress error, input remaining\n");
127 total += stream->buf.out_pos;
128 mutex_unlock(&msblk->read_data_mutex);
132 mutex_unlock(&msblk->read_data_mutex);
140 const struct squashfs_decompressor squashfs_xz_comp_ops = {
141 .init = squashfs_xz_init,
142 .free = squashfs_xz_free,
143 .decompress = squashfs_xz_uncompress,
144 .id = XZ_COMPRESSION,