/*
* 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 Library
* General Public License, version 2.
* %End-Header%
*/
#ifndef _EXT2FS_EXT2_IO_H
#define _EXT2FS_EXT2_IO_H
/*
* 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);
typedef struct struct_io_manager *io_manager;
typedef struct struct_io_channel *io_channel;
typedef struct struct_io_stats *io_stats;
#define CHANNEL_FLAGS_WRITETHROUGH 0x01
#define CHANNEL_FLAGS_DISCARD_ZEROES 0x02
#define CHANNEL_FLAGS_BLOCK_DEVICE 0x04
#define io_channel_discard_zeroes_data(i) (i->flags & CHANNEL_FLAGS_DISCARD_ZEROES)
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;
long reserved[14];
void *private_data;
void *app_data;
int align;
};
struct struct_io_stats {
int num_fields;
int reserved;
unsigned long long bytes_read;
unsigned long long bytes_written;
};
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);
errcode_t (*get_stats)(io_channel channel, io_stats *io_stats);
errcode_t (*read_blk64)(io_channel channel, unsigned long long block,
int count, void *data);
errcode_t (*write_blk64)(io_channel channel, unsigned long long block,
int count, const void *data);
errcode_t (*discard)(io_channel channel, unsigned long long block,
unsigned long long count);
long reserved[16];
};
#define IO_FLAG_RW 0x0001
#define IO_FLAG_EXCLUSIVE 0x0002
#define IO_FLAG_DIRECT_IO 0x0004
/*
* 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);
extern errcode_t io_channel_read_blk64(io_channel channel,
unsigned long long block,
int count, void *data);
extern errcode_t io_channel_write_blk64(io_channel channel,
unsigned long long block,
int count, const void *data);
extern errcode_t io_channel_discard(io_channel channel,
unsigned long long block,
unsigned long long count);
extern errcode_t io_channel_alloc_buf(io_channel channel,
int count, void *ptr);
/* unix_io.c */
extern io_manager unix_io_manager;
/* undo_io.c */
extern io_manager undo_io_manager;
extern errcode_t set_undo_io_backing_manager(io_manager manager);
extern errcode_t set_undo_io_backup_file(char *file_name);
/* 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_read_blk64)
(unsigned long long block, int count, errcode_t err);
extern void (*test_io_cb_write_blk64)
(unsigned long long block, int count, errcode_t err);
extern void (*test_io_cb_set_blksize)
(int blksize, errcode_t err);
#endif /* _EXT2FS_EXT2_IO_H */