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![Phillip Lougher](/assets/img/avatar_default.png)
Extend decompressor framework to handle compression options stored in the filesystem. These options can be used by the relevant decompressor at initialisation time to over-ride defaults. The presence of compression options in the filesystem is indicated by the COMP_OPT filesystem flag. If present the data is read from the filesystem and passed to the decompressor init function. The decompressor init function signature has been extended to take this data. Also update the init function signature in the glib, lzo and xz decompressor wrappers. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
135 lines
3.2 KiB
C
135 lines
3.2 KiB
C
/*
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* Squashfs - a compressed read only filesystem for Linux
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*
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* Copyright (c) 2010 LG Electronics
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* Chan Jeong <chan.jeong@lge.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2,
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* or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* lzo_wrapper.c
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*/
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#include <linux/mutex.h>
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#include <linux/buffer_head.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/lzo.h>
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#include "squashfs_fs.h"
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#include "squashfs_fs_sb.h"
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#include "squashfs.h"
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#include "decompressor.h"
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struct squashfs_lzo {
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void *input;
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void *output;
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};
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static void *lzo_init(struct squashfs_sb_info *msblk, void *buff, int len)
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{
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int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
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struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
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if (stream == NULL)
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goto failed;
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stream->input = vmalloc(block_size);
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if (stream->input == NULL)
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goto failed;
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stream->output = vmalloc(block_size);
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if (stream->output == NULL)
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goto failed2;
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return stream;
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failed2:
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vfree(stream->input);
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failed:
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ERROR("Failed to allocate lzo workspace\n");
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kfree(stream);
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return ERR_PTR(-ENOMEM);
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}
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static void lzo_free(void *strm)
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{
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struct squashfs_lzo *stream = strm;
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if (stream) {
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vfree(stream->input);
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vfree(stream->output);
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}
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kfree(stream);
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}
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static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer,
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struct buffer_head **bh, int b, int offset, int length, int srclength,
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int pages)
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{
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struct squashfs_lzo *stream = msblk->stream;
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void *buff = stream->input;
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int avail, i, bytes = length, res;
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size_t out_len = srclength;
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mutex_lock(&msblk->read_data_mutex);
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for (i = 0; i < b; i++) {
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wait_on_buffer(bh[i]);
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if (!buffer_uptodate(bh[i]))
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goto block_release;
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avail = min(bytes, msblk->devblksize - offset);
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memcpy(buff, bh[i]->b_data + offset, avail);
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buff += avail;
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bytes -= avail;
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offset = 0;
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put_bh(bh[i]);
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}
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res = lzo1x_decompress_safe(stream->input, (size_t)length,
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stream->output, &out_len);
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if (res != LZO_E_OK)
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goto failed;
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res = bytes = (int)out_len;
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for (i = 0, buff = stream->output; bytes && i < pages; i++) {
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avail = min_t(int, bytes, PAGE_CACHE_SIZE);
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memcpy(buffer[i], buff, avail);
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buff += avail;
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bytes -= avail;
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}
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mutex_unlock(&msblk->read_data_mutex);
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return res;
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block_release:
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for (; i < b; i++)
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put_bh(bh[i]);
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failed:
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mutex_unlock(&msblk->read_data_mutex);
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ERROR("lzo decompression failed, data probably corrupt\n");
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return -EIO;
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}
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const struct squashfs_decompressor squashfs_lzo_comp_ops = {
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.init = lzo_init,
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.free = lzo_free,
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.decompress = lzo_uncompress,
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.id = LZO_COMPRESSION,
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.name = "lzo",
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.supported = 1
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};
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