[1765] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * io.h --- the I/O manager abstraction
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| 4 | *
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| 5 | * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
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| 6 | *
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| 7 | * %Begin-Header%
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| 8 | * This file may be redistributed under the terms of the GNU Public
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| 9 | * License.
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| 10 | * %End-Header%
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| 11 | */
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| 12 |
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| 13 | #ifndef _EXT2FS_EXT2_IO_H
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| 14 | #define _EXT2FS_EXT2_IO_H
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| 15 |
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| 16 | /*
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| 17 | * ext2_loff_t is defined here since unix_io.c needs it.
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| 18 | */
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| 19 | #if defined(__GNUC__) || defined(HAS_LONG_LONG)
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| 20 | typedef long long ext2_loff_t;
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| 21 | #else
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| 22 | typedef long ext2_loff_t;
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| 23 | #endif
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| 24 |
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| 25 | /* llseek.c */
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| 26 | /* ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); */
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| 27 | #ifdef CONFIG_LFS
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| 28 | # define ext2fs_llseek lseek64
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| 29 | #else
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| 30 | # define ext2fs_llseek lseek
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| 31 | #endif
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| 32 |
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| 33 | typedef struct struct_io_manager *io_manager;
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| 34 | typedef struct struct_io_channel *io_channel;
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| 35 |
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| 36 | #define CHANNEL_FLAGS_WRITETHROUGH 0x01
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| 37 |
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| 38 | struct struct_io_channel {
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| 39 | errcode_t magic;
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| 40 | io_manager manager;
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| 41 | char *name;
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| 42 | int block_size;
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| 43 | errcode_t (*read_error)(io_channel channel,
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| 44 | unsigned long block,
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| 45 | int count,
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| 46 | void *data,
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| 47 | size_t size,
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| 48 | int actual_bytes_read,
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| 49 | errcode_t error);
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| 50 | errcode_t (*write_error)(io_channel channel,
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| 51 | unsigned long block,
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| 52 | int count,
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| 53 | const void *data,
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| 54 | size_t size,
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| 55 | int actual_bytes_written,
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| 56 | errcode_t error);
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| 57 | int refcount;
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| 58 | int flags;
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| 59 | int reserved[14];
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| 60 | void *private_data;
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| 61 | void *app_data;
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| 62 | };
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| 63 |
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| 64 | struct struct_io_manager {
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| 65 | errcode_t magic;
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| 66 | const char *name;
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| 67 | errcode_t (*open)(const char *name, int flags, io_channel *channel);
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| 68 | errcode_t (*close)(io_channel channel);
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| 69 | errcode_t (*set_blksize)(io_channel channel, int blksize);
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| 70 | errcode_t (*read_blk)(io_channel channel, unsigned long block,
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| 71 | int count, void *data);
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| 72 | errcode_t (*write_blk)(io_channel channel, unsigned long block,
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| 73 | int count, const void *data);
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| 74 | errcode_t (*flush)(io_channel channel);
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| 75 | errcode_t (*write_byte)(io_channel channel, unsigned long offset,
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| 76 | int count, const void *data);
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| 77 | errcode_t (*set_option)(io_channel channel, const char *option,
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| 78 | const char *arg);
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| 79 | int reserved[14];
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| 80 | };
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| 81 |
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| 82 | #define IO_FLAG_RW 1
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| 83 |
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| 84 | /*
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| 85 | * Convenience functions....
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| 86 | */
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| 87 | #define io_channel_close(c) ((c)->manager->close((c)))
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| 88 | #define io_channel_set_blksize(c,s) ((c)->manager->set_blksize((c),s))
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| 89 | #define io_channel_read_blk(c,b,n,d) ((c)->manager->read_blk((c),b,n,d))
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| 90 | #define io_channel_write_blk(c,b,n,d) ((c)->manager->write_blk((c),b,n,d))
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| 91 | #define io_channel_flush(c) ((c)->manager->flush((c)))
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| 92 | #define io_channel_bumpcount(c) ((c)->refcount++)
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| 93 |
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| 94 | /* io_manager.c */
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| 95 | extern errcode_t io_channel_set_options(io_channel channel,
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| 96 | const char *options);
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| 97 | extern errcode_t io_channel_write_byte(io_channel channel,
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| 98 | unsigned long offset,
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| 99 | int count, const void *data);
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| 100 |
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| 101 | /* unix_io.c */
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| 102 | extern io_manager unix_io_manager;
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| 103 |
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| 104 | /* test_io.c */
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| 105 | extern io_manager test_io_manager, test_io_backing_manager;
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| 106 | extern void (*test_io_cb_read_blk)
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| 107 | (unsigned long block, int count, errcode_t err);
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| 108 | extern void (*test_io_cb_write_blk)
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| 109 | (unsigned long block, int count, errcode_t err);
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| 110 | extern void (*test_io_cb_set_blksize)
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| 111 | (int blksize, errcode_t err);
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| 112 |
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| 113 | #endif /* _EXT2FS_EXT2_IO_H */
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| 114 |
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