From 6c4419d997d4431bb62e73475cd6b084e83efbd1 Mon Sep 17 00:00:00 2001 From: Phillip Lougher <phillip@lougher.demon.co.uk> Date: Tue, 22 Sep 2009 19:25:24 +0100 Subject: [PATCH] Squashfs: move zlib decompression wrapper code into a separate file Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk> --- fs/squashfs/Makefile | 2 +- fs/squashfs/block.c | 74 ++---------------------------- fs/squashfs/squashfs.h | 4 ++ fs/squashfs/zlib_wrapper.c | 109 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 118 insertions(+), 71 deletions(-) create mode 100644 fs/squashfs/zlib_wrapper.c --- a/fs/squashfs/Makefile +++ b/fs/squashfs/Makefile @@ -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 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -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_bloc } 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 = 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_bloc kfree(bh); return length; -release_mutex: - mutex_unlock(&msblk->read_data_mutex); - block_release: for (; k < b; k++) put_bh(bh[k]); --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -70,6 +70,10 @@ extern struct inode *squashfs_iget(struc unsigned int); extern int squashfs_read_inode(struct inode *, long long); +/* zlib_wrapper.c */ +extern int zlib_uncompress(struct squashfs_sb_info *, void **, + struct buffer_head **, int, int, int, int, int); + /* * Inodes and files operations */ --- /dev/null +++ b/fs/squashfs/zlib_wrapper.c @@ -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 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; +}