git.maemo.org Git - busybox4maemo/blob - e2fsprogs/old_e2fsprogs/ext2fs/ext2_io.h

   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
  13 #ifndef _EXT2FS_EXT2_IO_H
  14 #define _EXT2FS_EXT2_IO_H
  15
  16 /*
  17  * ext2_loff_t is defined here since unix_io.c needs it.
  18  */
  19 #if defined(__GNUC__) || defined(HAS_LONG_LONG)
  20 typedef long long       ext2_loff_t;
  21 #else
  22 typedef long            ext2_loff_t;
  23 #endif
  24
  25 /* llseek.c */
  26 /* ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); */
  27 #ifdef CONFIG_LFS
  28 # define ext2fs_llseek lseek64
  29 #else
  30 # define ext2fs_llseek lseek
  31 #endif
  32
  33 typedef struct struct_io_manager *io_manager;
  34 typedef struct struct_io_channel *io_channel;
  35
  36 #define CHANNEL_FLAGS_WRITETHROUGH      0x01
  37
  38 struct struct_io_channel {
  39         errcode_t       magic;
  40         io_manager      manager;
  41         char            *name;
  42         int             block_size;
  43         errcode_t       (*read_error)(io_channel channel,
  44                                       unsigned long block,
  45                                       int count,
  46                                       void *data,
  47                                       size_t size,
  48                                       int actual_bytes_read,
  49                                       errcode_t error);
  50         errcode_t       (*write_error)(io_channel channel,
  51                                        unsigned long block,
  52                                        int count,
  53                                        const void *data,
  54                                        size_t size,
  55                                        int actual_bytes_written,
  56                                        errcode_t error);
  57         int             refcount;
  58         int             flags;
  59         int             reserved[14];
  60         void            *private_data;
  61         void            *app_data;
  62 };
  63
  64 struct struct_io_manager {
  65         errcode_t magic;
  66         const char *name;
  67         errcode_t (*open)(const char *name, int flags, io_channel *channel);
  68         errcode_t (*close)(io_channel channel);
  69         errcode_t (*set_blksize)(io_channel channel, int blksize);
  70         errcode_t (*read_blk)(io_channel channel, unsigned long block,
  71                               int count, void *data);
  72         errcode_t (*write_blk)(io_channel channel, unsigned long block,
  73                                int count, const void *data);
  74         errcode_t (*flush)(io_channel channel);
  75         errcode_t (*write_byte)(io_channel channel, unsigned long offset,
  76                                 int count, const void *data);
  77         errcode_t (*set_option)(io_channel channel, const char *option,
  78                                 const char *arg);
  79         int             reserved[14];
  80 };
  81
  82 #define IO_FLAG_RW      1
  83
  84 /*
  85  * Convenience functions....
  86  */
  87 #define io_channel_close(c)             ((c)->manager->close((c)))
  88 #define io_channel_set_blksize(c,s)     ((c)->manager->set_blksize((c),s))
  89 #define io_channel_read_blk(c,b,n,d)    ((c)->manager->read_blk((c),b,n,d))
  90 #define io_channel_write_blk(c,b,n,d)   ((c)->manager->write_blk((c),b,n,d))
  91 #define io_channel_flush(c)             ((c)->manager->flush((c)))
  92 #define io_channel_bumpcount(c)         ((c)->refcount++)
  93
  94 /* io_manager.c */
  95 extern errcode_t io_channel_set_options(io_channel channel,
  96                                         const char *options);
  97 extern errcode_t io_channel_write_byte(io_channel channel,
  98                                        unsigned long offset,
  99                                        int count, const void *data);
 100
 101 /* unix_io.c */
 102 extern io_manager unix_io_manager;
 103
 104 /* test_io.c */
 105 extern io_manager test_io_manager, test_io_backing_manager;
 106 extern void (*test_io_cb_read_blk)
 107         (unsigned long block, int count, errcode_t err);
 108 extern void (*test_io_cb_write_blk)
 109         (unsigned long block, int count, errcode_t err);
 110 extern void (*test_io_cb_set_blksize)
 111         (int blksize, errcode_t err);
 112
 113 #endif /* _EXT2FS_EXT2_IO_H */
 114