--- /dev/null
+From 327fbf47a419befc6bff74f3ca42d2b6f0841903 Mon Sep 17 00:00:00 2001
+From: Phillip Lougher <phillip@lougher.demon.co.uk>
+Date: Tue, 6 Oct 2009 04:04:15 +0100
+Subject: [PATCH] Squashfs: add a decompressor framework
+
+This adds a decompressor framework which allows multiple compression
+algorithms to be cleanly supported.
+
+Also update zlib wrapper and other code to use the new framework.
+
+Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
+---
+ fs/squashfs/Makefile | 2 +-
+ fs/squashfs/block.c | 6 ++--
+ fs/squashfs/decompressor.c | 58 ++++++++++++++++++++++++++++++++++++++++++
+ fs/squashfs/decompressor.h | 55 +++++++++++++++++++++++++++++++++++++++
+ fs/squashfs/squashfs.h | 14 +++++-----
+ fs/squashfs/squashfs_fs_sb.h | 41 +++++++++++++++--------------
+ fs/squashfs/super.c | 45 ++++++++++++++++++-------------
+ fs/squashfs/zlib_wrapper.c | 17 ++++++++++--
+ 8 files changed, 185 insertions(+), 53 deletions(-)
+ create mode 100644 fs/squashfs/decompressor.c
+ create mode 100644 fs/squashfs/decompressor.h
+
+--- 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 zlib_wrapper.o
++squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
+--- a/fs/squashfs/block.c
++++ b/fs/squashfs/block.c
+@@ -36,7 +36,7 @@
+ #include "squashfs_fs_sb.h"
+ #include "squashfs_fs_i.h"
+ #include "squashfs.h"
+-
++#include "decompressor.h"
+ /*
+ * Read the metadata block length, this is stored in the first two
+ * bytes of the metadata block.
+@@ -151,8 +151,8 @@ int squashfs_read_data(struct super_bloc
+ }
+
+ if (compressed) {
+- length = zlib_uncompress(msblk, buffer, bh, b, offset, length,
+- srclength, pages);
++ length = squashfs_decompress(msblk, buffer, bh, b, offset,
++ length, srclength, pages);
+ if (length < 0)
+ goto read_failure;
+ } else {
+--- /dev/null
++++ b/fs/squashfs/decompressor.c
+@@ -0,0 +1,58 @@
++/*
++ * 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.
++ *
++ * decompressor.c
++ */
++
++#include <linux/types.h>
++#include <linux/mutex.h>
++#include <linux/buffer_head.h>
++
++#include "squashfs_fs.h"
++#include "squashfs_fs_sb.h"
++#include "squashfs_fs_i.h"
++#include "decompressor.h"
++#include "squashfs.h"
++
++/*
++ * This file (and decompressor.h) implements a decompressor framework for
++ * Squashfs, allowing multiple decompressors to be easily supported
++ */
++
++static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
++ NULL, NULL, NULL, 0, "unknown", 0
++};
++
++static const struct squashfs_decompressor *decompressor[] = {
++ &squashfs_zlib_comp_ops,
++ &squashfs_unknown_comp_ops
++};
++
++
++const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
++{
++ int i;
++
++ for (i = 0; decompressor[i]->id; i++)
++ if (id == decompressor[i]->id)
++ break;
++
++ return decompressor[i];
++}
+--- /dev/null
++++ b/fs/squashfs/decompressor.h
+@@ -0,0 +1,55 @@
++#ifndef DECOMPRESSOR_H
++#define DECOMPRESSOR_H
++/*
++ * 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.
++ *
++ * decompressor.h
++ */
++
++struct squashfs_decompressor {
++ void *(*init)(void);
++ void (*free)(void *);
++ int (*decompress)(struct squashfs_sb_info *, void **,
++ struct buffer_head **, int, int, int, int, int);
++ int id;
++ char *name;
++ int supported;
++};
++
++static inline void *squashfs_decompressor_init(struct squashfs_sb_info *msblk)
++{
++ return msblk->decompressor->init();
++}
++
++static inline void squashfs_decompressor_free(struct squashfs_sb_info *msblk,
++ void *s)
++{
++ if (msblk->decompressor)
++ msblk->decompressor->free(s);
++}
++
++static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
++ void **buffer, struct buffer_head **bh, int b, int offset, int length,
++ int srclength, int pages)
++{
++ return msblk->decompressor->decompress(msblk, buffer, bh, b, offset,
++ length, srclength, pages);
++}
++#endif
+--- a/fs/squashfs/squashfs.h
++++ b/fs/squashfs/squashfs.h
+@@ -51,6 +51,9 @@ extern struct squashfs_cache_entry *squa
+ u64, int);
+ extern int squashfs_read_table(struct super_block *, void *, u64, int);
+
++/* decompressor.c */
++extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
++
+ /* export.c */
+ extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64,
+ unsigned int);
+@@ -70,14 +73,8 @@ extern struct inode *squashfs_iget(struc
+ unsigned int);
+ extern int squashfs_read_inode(struct inode *, long long);
+
+-/* zlib_wrapper.c */
+-extern void *zlib_init(void);
+-extern void zlib_free(void *);
+-extern int zlib_uncompress(struct squashfs_sb_info *, void **,
+- struct buffer_head **, int, int, int, int, int);
+-
+ /*
+- * Inodes and files operations
++ * Inodes, files and decompressor operations
+ */
+
+ /* dir.c */
+@@ -94,3 +91,6 @@ extern const struct inode_operations squ
+
+ /* symlink.c */
+ extern const struct address_space_operations squashfs_symlink_aops;
++
++/* zlib_wrapper.c */
++extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
+--- a/fs/squashfs/squashfs_fs_sb.h
++++ b/fs/squashfs/squashfs_fs_sb.h
+@@ -52,25 +52,26 @@ struct squashfs_cache_entry {
+ };
+
+ struct squashfs_sb_info {
+- int devblksize;
+- int devblksize_log2;
+- struct squashfs_cache *block_cache;
+- struct squashfs_cache *fragment_cache;
+- struct squashfs_cache *read_page;
+- int next_meta_index;
+- __le64 *id_table;
+- __le64 *fragment_index;
+- unsigned int *fragment_index_2;
+- struct mutex read_data_mutex;
+- struct mutex meta_index_mutex;
+- struct meta_index *meta_index;
+- void *stream;
+- __le64 *inode_lookup_table;
+- u64 inode_table;
+- u64 directory_table;
+- unsigned int block_size;
+- unsigned short block_log;
+- long long bytes_used;
+- unsigned int inodes;
++ const struct squashfs_decompressor *decompressor;
++ int devblksize;
++ int devblksize_log2;
++ struct squashfs_cache *block_cache;
++ struct squashfs_cache *fragment_cache;
++ struct squashfs_cache *read_page;
++ int next_meta_index;
++ __le64 *id_table;
++ __le64 *fragment_index;
++ unsigned int *fragment_index_2;
++ struct mutex read_data_mutex;
++ struct mutex meta_index_mutex;
++ struct meta_index *meta_index;
++ void *stream;
++ __le64 *inode_lookup_table;
++ u64 inode_table;
++ u64 directory_table;
++ unsigned int block_size;
++ unsigned short block_log;
++ long long bytes_used;
++ unsigned int inodes;
+ };
+ #endif
+--- a/fs/squashfs/super.c
++++ b/fs/squashfs/super.c
+@@ -41,27 +41,35 @@
+ #include "squashfs_fs_sb.h"
+ #include "squashfs_fs_i.h"
+ #include "squashfs.h"
++#include "decompressor.h"
+
+ static struct file_system_type squashfs_fs_type;
+ static struct super_operations squashfs_super_ops;
+
+-static int supported_squashfs_filesystem(short major, short minor, short comp)
++static const struct squashfs_decompressor *supported_squashfs_filesystem(short
++ major, short minor, short id)
+ {
++ const struct squashfs_decompressor *decompressor;
++
+ if (major < SQUASHFS_MAJOR) {
+ ERROR("Major/Minor mismatch, older Squashfs %d.%d "
+ "filesystems are unsupported\n", major, minor);
+- return -EINVAL;
++ return NULL;
+ } else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
+ ERROR("Major/Minor mismatch, trying to mount newer "
+ "%d.%d filesystem\n", major, minor);
+ ERROR("Please update your kernel\n");
+- return -EINVAL;
++ return NULL;
+ }
+
+- if (comp != ZLIB_COMPRESSION)
+- return -EINVAL;
++ decompressor = squashfs_lookup_decompressor(id);
++ if (!decompressor->supported) {
++ ERROR("Filesystem uses \"%s\" compression. This is not "
++ "supported\n", decompressor->name);
++ return NULL;
++ }
+
+- return 0;
++ return decompressor;
+ }
+
+
+@@ -86,10 +94,6 @@ static int squashfs_fill_super(struct su
+ }
+ msblk = sb->s_fs_info;
+
+- msblk->stream = zlib_init();
+- if (msblk->stream == NULL)
+- goto failure;
+-
+ sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
+ if (sblk == NULL) {
+ ERROR("Failed to allocate squashfs_super_block\n");
+@@ -116,25 +120,25 @@ static int squashfs_fill_super(struct su
+ goto failed_mount;
+ }
+
++ err = -EINVAL;
++
+ /* Check it is a SQUASHFS superblock */
+ sb->s_magic = le32_to_cpu(sblk->s_magic);
+ if (sb->s_magic != SQUASHFS_MAGIC) {
+ if (!silent)
+ ERROR("Can't find a SQUASHFS superblock on %s\n",
+ bdevname(sb->s_bdev, b));
+- err = -EINVAL;
+ goto failed_mount;
+ }
+
+- /* Check the MAJOR & MINOR versions and compression type */
+- err = supported_squashfs_filesystem(le16_to_cpu(sblk->s_major),
++ /* Check the MAJOR & MINOR versions and lookup compression type */
++ msblk->decompressor = supported_squashfs_filesystem(
++ le16_to_cpu(sblk->s_major),
+ le16_to_cpu(sblk->s_minor),
+ le16_to_cpu(sblk->compression));
+- if (err < 0)
++ if (msblk->decompressor == NULL)
+ goto failed_mount;
+
+- err = -EINVAL;
+-
+ /*
+ * Check if there's xattrs in the filesystem. These are not
+ * supported in this version, so warn that they will be ignored.
+@@ -201,6 +205,10 @@ static int squashfs_fill_super(struct su
+
+ err = -ENOMEM;
+
++ msblk->stream = squashfs_decompressor_init(msblk);
++ if (msblk->stream == NULL)
++ goto failed_mount;
++
+ msblk->block_cache = squashfs_cache_init("metadata",
+ SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
+ if (msblk->block_cache == NULL)
+@@ -288,7 +296,7 @@ failed_mount:
+ squashfs_cache_delete(msblk->block_cache);
+ squashfs_cache_delete(msblk->fragment_cache);
+ squashfs_cache_delete(msblk->read_page);
+- zlib_free(msblk->stream);
++ squashfs_decompressor_free(msblk, msblk->stream);
+ kfree(msblk->inode_lookup_table);
+ kfree(msblk->fragment_index);
+ kfree(msblk->id_table);
+@@ -298,7 +306,6 @@ failed_mount:
+ return err;
+
+ failure:
+- zlib_free(msblk->stream);
+ kfree(sb->s_fs_info);
+ sb->s_fs_info = NULL;
+ return -ENOMEM;
+@@ -342,7 +349,7 @@ static void squashfs_put_super(struct su
+ squashfs_cache_delete(sbi->block_cache);
+ squashfs_cache_delete(sbi->fragment_cache);
+ squashfs_cache_delete(sbi->read_page);
+- zlib_free(sbi->stream);
++ squashfs_decompressor_free(sbi, sbi->stream);
+ kfree(sbi->id_table);
+ kfree(sbi->fragment_index);
+ kfree(sbi->meta_index);
+--- a/fs/squashfs/zlib_wrapper.c
++++ b/fs/squashfs/zlib_wrapper.c
+@@ -30,8 +30,9 @@
+ #include "squashfs_fs_sb.h"
+ #include "squashfs_fs_i.h"
+ #include "squashfs.h"
++#include "decompressor.h"
+
+-void *zlib_init()
++static void *zlib_init(void)
+ {
+ z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
+ if (stream == NULL)
+@@ -50,7 +51,7 @@ failed:
+ }
+
+
+-void zlib_free(void *strm)
++static void zlib_free(void *strm)
+ {
+ z_stream *stream = strm;
+
+@@ -60,7 +61,7 @@ void zlib_free(void *strm)
+ }
+
+
+-int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
++static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
+ struct buffer_head **bh, int b, int offset, int length, int srclength,
+ int pages)
+ {
+@@ -137,3 +138,13 @@ release_mutex:
+
+ return -EIO;
+ }
++
++const struct squashfs_decompressor squashfs_zlib_comp_ops = {
++ .init = zlib_init,
++ .free = zlib_free,
++ .decompress = zlib_uncompress,
++ .id = ZLIB_COMPRESSION,
++ .name = "zlib",
++ .supported = 1
++};
++
projects / openwrt.git / blobdiff