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 # define ext2fs_llseek lseek64
29 # define ext2fs_llseek lseek
32 typedef struct struct_io_manager *io_manager;
33 typedef struct struct_io_channel *io_channel;
35 #define CHANNEL_FLAGS_WRITETHROUGH 0x01
37 struct struct_io_channel {
42 errcode_t (*read_error)(io_channel channel,
47 int actual_bytes_read,
49 errcode_t (*write_error)(io_channel channel,
54 int actual_bytes_written,
63 struct struct_io_manager {
66 errcode_t (*open)(const char *name, int flags, io_channel *channel);
67 errcode_t (*close)(io_channel channel);
68 errcode_t (*set_blksize)(io_channel channel, int blksize);
69 errcode_t (*read_blk)(io_channel channel, unsigned long block,
70 int count, void *data);
71 errcode_t (*write_blk)(io_channel channel, unsigned long block,
72 int count, const void *data);
73 errcode_t (*flush)(io_channel channel);
74 errcode_t (*write_byte)(io_channel channel, unsigned long offset,
75 int count, const void *data);
76 errcode_t (*set_option)(io_channel channel, const char *option,
84 * Convenience functions....
86 #define io_channel_close(c) ((c)->manager->close((c)))
87 #define io_channel_set_blksize(c,s) ((c)->manager->set_blksize((c),s))
88 #define io_channel_read_blk(c,b,n,d) ((c)->manager->read_blk((c),b,n,d))
89 #define io_channel_write_blk(c,b,n,d) ((c)->manager->write_blk((c),b,n,d))
90 #define io_channel_flush(c) ((c)->manager->flush((c)))
91 #define io_channel_bumpcount(c) ((c)->refcount++)
94 extern errcode_t io_channel_set_options(io_channel channel,
96 extern errcode_t io_channel_write_byte(io_channel channel,
98 int count, const void *data);
101 extern io_manager unix_io_manager;
104 extern io_manager test_io_manager, test_io_backing_manager;
105 extern void (*test_io_cb_read_blk)
106 (unsigned long block, int count, errcode_t err);
107 extern void (*test_io_cb_write_blk)
108 (unsigned long block, int count, errcode_t err);
109 extern void (*test_io_cb_set_blksize)
110 (int blksize, errcode_t err);
112 #endif /* _EXT2FS_EXT2_IO_H */