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Squashfs: move zlib decompression wrapper code into a separate file 

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
This commit is contained in:
Phillip Lougher 2009-09-22 19:25:24 +01:00
parent 7284ce6c9f
commit e6a6d37955
4 changed files with 118 additions and 71 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/squashfs/Makefile
View File

@ -4,4 +4,4 @@
obj-$(CONFIG_SQUASHFS) += squashfs.o
squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
squashfs-y += namei.o super.o symlink.o
squashfs-y += namei.o super.o symlink.o zlib_wrapper.o

74
fs/squashfs/block.c
View File

@ -29,7 +29,6 @@
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/zlib.h>
@ -153,72 +152,10 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
}
if (compressed) {
int zlib_err = 0, zlib_init = 0;
/*
* Uncompress block.
*/
mutex_lock(&msblk->read_data_mutex);
msblk->stream.avail_out = 0;
msblk->stream.avail_in = 0;
bytes = length;
do {
if (msblk->stream.avail_in == 0 && k < b) {
avail = min(bytes, msblk->devblksize - offset);
bytes -= avail;
wait_on_buffer(bh[k]);
if (!buffer_uptodate(bh[k]))
goto release_mutex;
if (avail == 0) {
offset = 0;
put_bh(bh[k++]);
continue;
}
msblk->stream.next_in = bh[k]->b_data + offset;
msblk->stream.avail_in = avail;
offset = 0;
}
if (msblk->stream.avail_out == 0 && page < pages) {
msblk->stream.next_out = buffer[page++];
msblk->stream.avail_out = PAGE_CACHE_SIZE;
}
if (!zlib_init) {
zlib_err = zlib_inflateInit(&msblk->stream);
if (zlib_err != Z_OK) {
ERROR("zlib_inflateInit returned"
" unexpected result 0x%x,"
" srclength %d\n", zlib_err,
srclength);
goto release_mutex;
}
zlib_init = 1;
}
zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
if (msblk->stream.avail_in == 0 && k < b)
put_bh(bh[k++]);
} while (zlib_err == Z_OK);
if (zlib_err != Z_STREAM_END) {
ERROR("zlib_inflate error, data probably corrupt\n");
goto release_mutex;
}
zlib_err = zlib_inflateEnd(&msblk->stream);
if (zlib_err != Z_OK) {
ERROR("zlib_inflate error, data probably corrupt\n");
goto release_mutex;
}
length = msblk->stream.total_out;
mutex_unlock(&msblk->read_data_mutex);
length = squashfs_zlib_uncompress(msblk, buffer, bh, b, offset,
length, srclength, pages);
if (length < 0)
goto read_failure;
} else {
/*
* Block is uncompressed.
@ -255,9 +192,6 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
kfree(bh);
return length;
release_mutex:
mutex_unlock(&msblk->read_data_mutex);
block_release:
for (; k < b; k++)
put_bh(bh[k]);

4
fs/squashfs/squashfs.h
View File

@ -70,6 +70,10 @@ extern struct inode *squashfs_iget(struct super_block *, long long,
unsigned int);
extern int squashfs_read_inode(struct inode *, long long);
/* zlib_wrapper.c */
extern int squashfs_zlib_uncompress(struct squashfs_sb_info *, void **,
struct buffer_head **, int, int, int, int, int);
/*
* Inodes and files operations
*/

109
fs/squashfs/zlib_wrapper.c Normal file
View File

@ -0,0 +1,109 @@
/*
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
* Phillip Lougher <phillip@lougher.demon.co.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/zlib.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs_fs_i.h"
#include "squashfs.h"
int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
struct buffer_head **bh, int b, int offset, int length, int srclength,
int pages)
{
int zlib_err = 0, zlib_init = 0;
int avail, bytes, k = 0, page = 0;
mutex_lock(&msblk->read_data_mutex);
msblk->stream.avail_out = 0;
msblk->stream.avail_in = 0;
bytes = length;
do {
if (msblk->stream.avail_in == 0 && k < b) {
avail = min(bytes, msblk->devblksize - offset);
bytes -= avail;
wait_on_buffer(bh[k]);
if (!buffer_uptodate(bh[k]))
goto release_mutex;
if (avail == 0) {
offset = 0;
put_bh(bh[k++]);
continue;
}
msblk->stream.next_in = bh[k]->b_data + offset;
msblk->stream.avail_in = avail;
offset = 0;
}
if (msblk->stream.avail_out == 0 && page < pages) {
msblk->stream.next_out = buffer[page++];
msblk->stream.avail_out = PAGE_CACHE_SIZE;
}
if (!zlib_init) {
zlib_err = zlib_inflateInit(&msblk->stream);
if (zlib_err != Z_OK) {
ERROR("zlib_inflateInit returned unexpected "
"result 0x%x, srclength %d\n",
zlib_err, srclength);
goto release_mutex;
}
zlib_init = 1;
}
zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
if (msblk->stream.avail_in == 0 && k < b)
put_bh(bh[k++]);
} while (zlib_err == Z_OK);
if (zlib_err != Z_STREAM_END) {
ERROR("zlib_inflate error, data probably corrupt\n");
goto release_mutex;
}
zlib_err = zlib_inflateEnd(&msblk->stream);
if (zlib_err != Z_OK) {
ERROR("zlib_inflate error, data probably corrupt\n");
goto release_mutex;
}
mutex_unlock(&msblk->read_data_mutex);
return msblk->stream.total_out;
release_mutex:
mutex_unlock(&msblk->read_data_mutex);
for (; k < b; k++)
put_bh(bh[k]);
return -EIO;
}