linux/fs/squashfs/squashfs.h
Phillip Lougher 9508c6b90b Squashfs: Refactor decompressor interface and code
The decompressor interface and code was written from
the point of view of single-threaded operation.  In doing
so it mixed a lot of single-threaded implementation specific
aspects into the decompressor code and elsewhere which makes it
difficult to seamlessly support multiple different decompressor
implementations.

This patch does the following:

1.  It removes compressor_options parsing from the decompressor
    init() function.  This allows the decompressor init() function
    to be dynamically called to instantiate multiple decompressors,
    without the compressor options needing to be read and parsed each
    time.

2.  It moves threading and all sleeping operations out of the
    decompressors.  In doing so, it makes the decompressors
    non-blocking wrappers which only deal with interfacing with
    the decompressor implementation.

3. It splits decompressor.[ch] into decompressor generic functions
   in decompressor.[ch], and moves the single threaded
   decompressor implementation into decompressor_single.c.

The result of this patch is Squashfs should now be able to
support multiple decompressors by adding new decompressor_xxx.c
files with specialised implementations of the functions in
decompressor_single.c

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: Minchan Kim <minchan@kernel.org>
2013-11-20 03:35:18 +00:00

107 lines
3.8 KiB
C

/*
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
* Phillip Lougher <phillip@squashfs.org.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.
*
* squashfs.h
*/
#define TRACE(s, args...) pr_debug("SQUASHFS: "s, ## args)
#define ERROR(s, args...) pr_err("SQUASHFS error: "s, ## args)
#define WARNING(s, args...) pr_warning("SQUASHFS: "s, ## args)
/* block.c */
extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *,
int, int);
/* cache.c */
extern struct squashfs_cache *squashfs_cache_init(char *, int, int);
extern void squashfs_cache_delete(struct squashfs_cache *);
extern struct squashfs_cache_entry *squashfs_cache_get(struct super_block *,
struct squashfs_cache *, u64, int);
extern void squashfs_cache_put(struct squashfs_cache_entry *);
extern int squashfs_copy_data(void *, struct squashfs_cache_entry *, int, int);
extern int squashfs_read_metadata(struct super_block *, void *, u64 *,
int *, int);
extern struct squashfs_cache_entry *squashfs_get_fragment(struct super_block *,
u64, int);
extern struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *,
u64, int);
extern void *squashfs_read_table(struct super_block *, u64, int);
/* decompressor.c */
extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
extern void *squashfs_decompressor_setup(struct super_block *, unsigned short);
/* decompressor_xxx.c */
extern void *squashfs_decompressor_create(struct squashfs_sb_info *, void *);
extern void squashfs_decompressor_destroy(struct squashfs_sb_info *);
extern int squashfs_decompress(struct squashfs_sb_info *, void **,
struct buffer_head **, int, int, int, int, int);
extern int squashfs_max_decompressors(void);
/* export.c */
extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64, u64,
unsigned int);
/* fragment.c */
extern int squashfs_frag_lookup(struct super_block *, unsigned int, u64 *);
extern __le64 *squashfs_read_fragment_index_table(struct super_block *,
u64, u64, unsigned int);
/* id.c */
extern int squashfs_get_id(struct super_block *, unsigned int, unsigned int *);
extern __le64 *squashfs_read_id_index_table(struct super_block *, u64, u64,
unsigned short);
/* inode.c */
extern struct inode *squashfs_iget(struct super_block *, long long,
unsigned int);
extern int squashfs_read_inode(struct inode *, long long);
/* xattr.c */
extern ssize_t squashfs_listxattr(struct dentry *, char *, size_t);
/*
* Inodes, files, decompressor and xattr operations
*/
/* dir.c */
extern const struct file_operations squashfs_dir_ops;
/* export.c */
extern const struct export_operations squashfs_export_ops;
/* file.c */
extern const struct address_space_operations squashfs_aops;
/* inode.c */
extern const struct inode_operations squashfs_inode_ops;
/* namei.c */
extern const struct inode_operations squashfs_dir_inode_ops;
/* symlink.c */
extern const struct address_space_operations squashfs_symlink_aops;
extern const struct inode_operations squashfs_symlink_inode_ops;
/* xattr.c */
extern const struct xattr_handler *squashfs_xattr_handlers[];