LXR busybox/e2fsprogs/old_e2fsprogs/ext2fs/ext2

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * io.h --- the I/O manager abstraction
   4 *
   5 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
   6 *
   7 * %Begin-Header%
   8 * This file may be redistributed under the terms of the GNU Public
   9 * License.
  10 * %End-Header%
  11 */
  12#ifndef EXT2FS_EXT2_IO_H
  13#define EXT2FS_EXT2_IO_H 1
  14
  15/*
  16 * ext2_loff_t is defined here since unix_io.c needs it.
  17 */
  18#if defined(__GNUC__) || defined(HAS_LONG_LONG)
  19typedef long long       ext2_loff_t;
  20#else
  21typedef long            ext2_loff_t;
  22#endif
  23
  24/* llseek.c */
  25/* ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); */
  26#ifdef CONFIG_LFS
  27# define ext2fs_llseek lseek64
  28#else
  29# define ext2fs_llseek lseek
  30#endif
  31
  32typedef struct struct_io_manager *io_manager;
  33typedef struct struct_io_channel *io_channel;
  34
  35#define CHANNEL_FLAGS_WRITETHROUGH      0x01
  36
  37struct struct_io_channel {
  38        errcode_t       magic;
  39        io_manager      manager;
  40        char            *name;
  41        int             block_size;
  42        errcode_t       (*read_error)(io_channel channel,
  43                                      unsigned long block,
  44                                      int count,
  45                                      void *data,
  46                                      size_t size,
  47                                      int actual_bytes_read,
  48                                      errcode_t error);
  49        errcode_t       (*write_error)(io_channel channel,
  50                                       unsigned long block,
  51                                       int count,
  52                                       const void *data,
  53                                       size_t size,
  54                                       int actual_bytes_written,
  55                                       errcode_t error);
  56        int             refcount;
  57        int             flags;
  58        int             reserved[14];
  59        void            *private_data;
  60        void            *app_data;
  61};
  62
  63struct struct_io_manager {
  64        errcode_t magic;
  65        const char *name;
  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,
  77                                const char *arg);
  78        int             reserved[14];
  79};
  80
  81#define IO_FLAG_RW      1
  82
  83/*
  84 * Convenience functions....
  85 */
  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++)
  92
  93/* io_manager.c */
  94extern errcode_t io_channel_set_options(io_channel channel,
  95                                        const char *options);
  96extern errcode_t io_channel_write_byte(io_channel channel,
  97                                       unsigned long offset,
  98                                       int count, const void *data);
  99
 100/* unix_io.c */
 101extern io_manager unix_io_manager;
 102
 103/* test_io.c */
 104extern io_manager test_io_manager, test_io_backing_manager;
 105extern void (*test_io_cb_read_blk)
 106        (unsigned long block, int count, errcode_t err);
 107extern void (*test_io_cb_write_blk)
 108        (unsigned long block, int count, errcode_t err);
 109extern void (*test_io_cb_set_blksize)
 110        (int blksize, errcode_t err);
 111
 112#endif
 113