113 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			113 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* vi: set sw=4 ts=4: */
 | |
| /*
 | |
|  * io.h --- the I/O manager abstraction
 | |
|  *
 | |
|  * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
 | |
|  *
 | |
|  * %Begin-Header%
 | |
|  * This file may be redistributed under the terms of the GNU Public
 | |
|  * License.
 | |
|  * %End-Header%
 | |
|  */
 | |
| #ifndef EXT2FS_EXT2_IO_H
 | |
| #define EXT2FS_EXT2_IO_H 1
 | |
| 
 | |
| /*
 | |
|  * ext2_loff_t is defined here since unix_io.c needs it.
 | |
|  */
 | |
| #if defined(__GNUC__) || defined(HAS_LONG_LONG)
 | |
| typedef long long	ext2_loff_t;
 | |
| #else
 | |
| typedef long		ext2_loff_t;
 | |
| #endif
 | |
| 
 | |
| /* llseek.c */
 | |
| /* ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); */
 | |
| #ifdef CONFIG_LFS
 | |
| # define ext2fs_llseek lseek64
 | |
| #else
 | |
| # define ext2fs_llseek lseek
 | |
| #endif
 | |
| 
 | |
| typedef struct struct_io_manager *io_manager;
 | |
| typedef struct struct_io_channel *io_channel;
 | |
| 
 | |
| #define CHANNEL_FLAGS_WRITETHROUGH	0x01
 | |
| 
 | |
| struct struct_io_channel {
 | |
| 	errcode_t	magic;
 | |
| 	io_manager	manager;
 | |
| 	char		*name;
 | |
| 	int		block_size;
 | |
| 	errcode_t	(*read_error)(io_channel channel,
 | |
| 				      unsigned long block,
 | |
| 				      int count,
 | |
| 				      void *data,
 | |
| 				      size_t size,
 | |
| 				      int actual_bytes_read,
 | |
| 				      errcode_t error);
 | |
| 	errcode_t       (*write_error)(io_channel channel,
 | |
| 				       unsigned long block,
 | |
| 				       int count,
 | |
| 				       const void *data,
 | |
| 				       size_t size,
 | |
| 				       int actual_bytes_written,
 | |
| 				       errcode_t error);
 | |
| 	int		refcount;
 | |
| 	int		flags;
 | |
| 	int		reserved[14];
 | |
| 	void		*private_data;
 | |
| 	void		*app_data;
 | |
| };
 | |
| 
 | |
| struct struct_io_manager {
 | |
| 	errcode_t magic;
 | |
| 	const char *name;
 | |
| 	errcode_t (*open)(const char *name, int flags, io_channel *channel);
 | |
| 	errcode_t (*close)(io_channel channel);
 | |
| 	errcode_t (*set_blksize)(io_channel channel, int blksize);
 | |
| 	errcode_t (*read_blk)(io_channel channel, unsigned long block,
 | |
| 			      int count, void *data);
 | |
| 	errcode_t (*write_blk)(io_channel channel, unsigned long block,
 | |
| 			       int count, const void *data);
 | |
| 	errcode_t (*flush)(io_channel channel);
 | |
| 	errcode_t (*write_byte)(io_channel channel, unsigned long offset,
 | |
| 				int count, const void *data);
 | |
| 	errcode_t (*set_option)(io_channel channel, const char *option,
 | |
| 				const char *arg);
 | |
| 	int             reserved[14];
 | |
| };
 | |
| 
 | |
| #define IO_FLAG_RW	1
 | |
| 
 | |
| /*
 | |
|  * Convenience functions....
 | |
|  */
 | |
| #define io_channel_close(c)		((c)->manager->close((c)))
 | |
| #define io_channel_set_blksize(c,s)	((c)->manager->set_blksize((c),s))
 | |
| #define io_channel_read_blk(c,b,n,d)	((c)->manager->read_blk((c),b,n,d))
 | |
| #define io_channel_write_blk(c,b,n,d)	((c)->manager->write_blk((c),b,n,d))
 | |
| #define io_channel_flush(c)		((c)->manager->flush((c)))
 | |
| #define io_channel_bumpcount(c)		((c)->refcount++)
 | |
| 
 | |
| /* io_manager.c */
 | |
| extern errcode_t io_channel_set_options(io_channel channel,
 | |
| 					const char *options);
 | |
| extern errcode_t io_channel_write_byte(io_channel channel,
 | |
| 				       unsigned long offset,
 | |
| 				       int count, const void *data);
 | |
| 
 | |
| /* unix_io.c */
 | |
| extern io_manager unix_io_manager;
 | |
| 
 | |
| /* test_io.c */
 | |
| extern io_manager test_io_manager, test_io_backing_manager;
 | |
| extern void (*test_io_cb_read_blk)
 | |
| 	(unsigned long block, int count, errcode_t err);
 | |
| extern void (*test_io_cb_write_blk)
 | |
| 	(unsigned long block, int count, errcode_t err);
 | |
| extern void (*test_io_cb_set_blksize)
 | |
| 	(int blksize, errcode_t err);
 | |
| 
 | |
| #endif
 |