2 * io.h --- the I/O manager abstraction
4 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Public
12 #ifndef _EXT2FS_EXT2_IO_H
13 #define _EXT2FS_EXT2_IO_H
16 * ext2_loff_t is defined here since unix_io.c needs it.
18 #if defined(__GNUC__) || defined(HAS_LONG_LONG)
19 typedef long long ext2_loff_t;
21 typedef long ext2_loff_t;
25 ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int);
27 typedef struct struct_io_manager *io_manager;
28 typedef struct struct_io_channel *io_channel;
30 struct struct_io_channel {
35 errcode_t (*read_error)(io_channel channel,
40 int actual_bytes_read,
42 errcode_t (*write_error)(io_channel channel,
47 int actual_bytes_written,
55 struct struct_io_manager {
58 errcode_t (*open)(const char *name, int flags, io_channel *channel);
59 errcode_t (*close)(io_channel channel);
60 errcode_t (*set_blksize)(io_channel channel, int blksize);
61 errcode_t (*read_blk)(io_channel channel, unsigned long block,
62 int count, void *data);
63 errcode_t (*write_blk)(io_channel channel, unsigned long block,
64 int count, const void *data);
65 errcode_t (*flush)(io_channel channel);
72 * Convenience functions....
74 #define io_channel_close(c) ((c)->manager->close((c)))
75 #define io_channel_set_blksize(c,s) ((c)->manager->set_blksize((c),s))
76 #define io_channel_read_blk(c,b,n,d) ((c)->manager->read_blk((c),b,n,d))
77 #define io_channel_write_blk(c,b,n,d) ((c)->manager->write_blk((c),b,n,d))
78 #define io_channel_flush(c) ((c)->manager->flush((c)))
79 #define io_channel_bumpcount(c) ((c)->refcount++)
82 extern io_manager unix_io_manager;
85 extern io_manager test_io_manager, test_io_backing_manager;
86 extern void (*test_io_cb_read_blk)
87 (unsigned long block, int count, errcode_t err);
88 extern void (*test_io_cb_write_blk)
89 (unsigned long block, int count, errcode_t err);
90 extern void (*test_io_cb_set_blksize)
91 (int blksize, errcode_t err);
93 #endif /* _EXT2FS_EXT2_IO_H */