115 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			115 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* vi: set sw=4 ts=4: */
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/*
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 * io.h --- the I/O manager abstraction
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 *
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 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
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 *
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 * %Begin-Header%
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 * This file may be redistributed under the terms of the GNU Public
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 * License.
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 * %End-Header%
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 */
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#ifndef _EXT2FS_EXT2_IO_H
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#define _EXT2FS_EXT2_IO_H
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/*
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 * ext2_loff_t is defined here since unix_io.c needs it.
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 */
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#if defined(__GNUC__) || defined(HAS_LONG_LONG)
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typedef long long	ext2_loff_t;
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#else
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typedef long		ext2_loff_t;
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#endif
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/* llseek.c */
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/* ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); */
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#ifdef CONFIG_LFS
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# define ext2fs_llseek lseek64
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#else
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# define ext2fs_llseek lseek
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#endif
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typedef struct struct_io_manager *io_manager;
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typedef struct struct_io_channel *io_channel;
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#define CHANNEL_FLAGS_WRITETHROUGH	0x01
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struct struct_io_channel {
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	errcode_t	magic;
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	io_manager	manager;
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	char		*name;
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	int		block_size;
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	errcode_t	(*read_error)(io_channel channel,
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				      unsigned long block,
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				      int count,
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				      void *data,
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				      size_t size,
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				      int actual_bytes_read,
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				      errcode_t error);
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	errcode_t       (*write_error)(io_channel channel,
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				       unsigned long block,
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				       int count,
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				       const void *data,
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				       size_t size,
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				       int actual_bytes_written,
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				       errcode_t error);
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	int		refcount;
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	int		flags;
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	int		reserved[14];
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	void		*private_data;
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	void		*app_data;
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};
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struct struct_io_manager {
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	errcode_t magic;
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	const char *name;
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	errcode_t (*open)(const char *name, int flags, io_channel *channel);
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	errcode_t (*close)(io_channel channel);
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	errcode_t (*set_blksize)(io_channel channel, int blksize);
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	errcode_t (*read_blk)(io_channel channel, unsigned long block,
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			      int count, void *data);
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	errcode_t (*write_blk)(io_channel channel, unsigned long block,
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			       int count, const void *data);
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	errcode_t (*flush)(io_channel channel);
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	errcode_t (*write_byte)(io_channel channel, unsigned long offset,
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				int count, const void *data);
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	errcode_t (*set_option)(io_channel channel, const char *option,
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				const char *arg);
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	int             reserved[14];
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};
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#define IO_FLAG_RW	1
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/*
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 * Convenience functions....
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 */
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#define io_channel_close(c)		((c)->manager->close((c)))
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#define io_channel_set_blksize(c,s)	((c)->manager->set_blksize((c),s))
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#define io_channel_read_blk(c,b,n,d)	((c)->manager->read_blk((c),b,n,d))
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#define io_channel_write_blk(c,b,n,d)	((c)->manager->write_blk((c),b,n,d))
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#define io_channel_flush(c)		((c)->manager->flush((c)))
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#define io_channel_bumpcount(c)		((c)->refcount++)
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/* io_manager.c */
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extern errcode_t io_channel_set_options(io_channel channel,
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					const char *options);
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extern errcode_t io_channel_write_byte(io_channel channel,
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				       unsigned long offset,
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				       int count, const void *data);
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/* unix_io.c */
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extern io_manager unix_io_manager;
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/* test_io.c */
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extern io_manager test_io_manager, test_io_backing_manager;
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extern void (*test_io_cb_read_blk)
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	(unsigned long block, int count, errcode_t err);
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extern void (*test_io_cb_write_blk)
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	(unsigned long block, int count, errcode_t err);
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extern void (*test_io_cb_set_blksize)
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	(int blksize, errcode_t err);
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#endif /* _EXT2FS_EXT2_IO_H */
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