173 lines
5.4 KiB
C
173 lines
5.4 KiB
C
/*
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* io.h --- the I/O manager abstraction
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*
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* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Library
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* General Public License, version 2.
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* %End-Header%
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*/
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#ifndef _EXT2FS_EXT2_IO_H
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#define _EXT2FS_EXT2_IO_H
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#include <ext2fs/ext2_types.h>
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/*
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* ext2_loff_t is defined here since unix_io.c needs it.
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*/
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#if defined(__GNUC__) || defined(HAS_LONG_LONG)
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typedef long long ext2_loff_t;
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#else
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typedef long ext2_loff_t;
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#endif
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/* llseek.c */
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ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int);
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typedef struct struct_io_manager *io_manager;
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typedef struct struct_io_channel *io_channel;
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typedef struct struct_io_stats *io_stats;
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#define CHANNEL_FLAGS_WRITETHROUGH 0x01
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#define CHANNEL_FLAGS_DISCARD_ZEROES 0x02
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#define CHANNEL_FLAGS_BLOCK_DEVICE 0x04
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#define CHANNEL_FLAGS_THREADS 0x08
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#define io_channel_discard_zeroes_data(i) (i->flags & CHANNEL_FLAGS_DISCARD_ZEROES)
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struct struct_io_channel {
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errcode_t magic;
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io_manager manager;
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char *name;
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int block_size;
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errcode_t (*read_error)(io_channel channel,
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unsigned long block,
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int count,
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void *data,
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size_t size,
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int actual_bytes_read,
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errcode_t error);
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errcode_t (*write_error)(io_channel channel,
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unsigned long block,
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int count,
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const void *data,
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size_t size,
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int actual_bytes_written,
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errcode_t error);
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int refcount;
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int flags;
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long reserved[14];
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void *private_data;
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void *app_data;
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int align;
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};
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struct struct_io_stats {
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int num_fields;
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int reserved;
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unsigned long long bytes_read;
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unsigned long long bytes_written;
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};
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struct struct_io_manager {
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errcode_t magic;
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const char *name;
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errcode_t (*open)(const char *name, int flags, io_channel *channel);
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errcode_t (*close)(io_channel channel);
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errcode_t (*set_blksize)(io_channel channel, int blksize);
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errcode_t (*read_blk)(io_channel channel, unsigned long block,
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int count, void *data);
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errcode_t (*write_blk)(io_channel channel, unsigned long block,
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int count, const void *data);
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errcode_t (*flush)(io_channel channel);
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errcode_t (*write_byte)(io_channel channel, unsigned long offset,
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int count, const void *data);
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errcode_t (*set_option)(io_channel channel, const char *option,
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const char *arg);
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errcode_t (*get_stats)(io_channel channel, io_stats *io_stats);
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errcode_t (*read_blk64)(io_channel channel, unsigned long long block,
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int count, void *data);
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errcode_t (*write_blk64)(io_channel channel, unsigned long long block,
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int count, const void *data);
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errcode_t (*discard)(io_channel channel, unsigned long long block,
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unsigned long long count);
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errcode_t (*cache_readahead)(io_channel channel,
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unsigned long long block,
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unsigned long long count);
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errcode_t (*zeroout)(io_channel channel, unsigned long long block,
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unsigned long long count);
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long reserved[14];
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};
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#define IO_FLAG_RW 0x0001
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#define IO_FLAG_EXCLUSIVE 0x0002
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#define IO_FLAG_DIRECT_IO 0x0004
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#define IO_FLAG_FORCE_BOUNCE 0x0008
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#define IO_FLAG_THREADS 0x0010
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#define IO_FLAG_NOCACHE 0x0020
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/*
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* Convenience functions....
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*/
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#define io_channel_close(c) ((c)->manager->close((c)))
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#define io_channel_set_blksize(c,s) ((c)->manager->set_blksize((c),s))
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#define io_channel_read_blk(c,b,n,d) ((c)->manager->read_blk((c),b,n,d))
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#define io_channel_write_blk(c,b,n,d) ((c)->manager->write_blk((c),b,n,d))
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#define io_channel_flush(c) ((c)->manager->flush((c)))
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#define io_channel_bumpcount(c) ((c)->refcount++)
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/* io_manager.c */
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extern errcode_t io_channel_set_options(io_channel channel,
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const char *options);
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extern errcode_t io_channel_write_byte(io_channel channel,
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unsigned long offset,
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int count, const void *data);
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extern errcode_t io_channel_read_blk64(io_channel channel,
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unsigned long long block,
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int count, void *data);
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extern errcode_t io_channel_write_blk64(io_channel channel,
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unsigned long long block,
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int count, const void *data);
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extern errcode_t io_channel_discard(io_channel channel,
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unsigned long long block,
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unsigned long long count);
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extern errcode_t io_channel_zeroout(io_channel channel,
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unsigned long long block,
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unsigned long long count);
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extern errcode_t io_channel_alloc_buf(io_channel channel,
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int count, void *ptr);
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extern errcode_t io_channel_cache_readahead(io_channel io,
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unsigned long long block,
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unsigned long long count);
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/* unix_io.c */
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extern io_manager unix_io_manager;
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extern io_manager unixfd_io_manager;
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/* sparse_io.c */
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extern io_manager sparse_io_manager;
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extern io_manager sparsefd_io_manager;
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/* undo_io.c */
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extern io_manager undo_io_manager;
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extern errcode_t set_undo_io_backing_manager(io_manager manager);
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extern errcode_t set_undo_io_backup_file(char *file_name);
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/* test_io.c */
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extern io_manager test_io_manager, test_io_backing_manager;
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extern void (*test_io_cb_read_blk)
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(unsigned long block, int count, errcode_t err);
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extern void (*test_io_cb_write_blk)
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(unsigned long block, int count, errcode_t err);
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extern void (*test_io_cb_read_blk64)
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(unsigned long long block, int count, errcode_t err);
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extern void (*test_io_cb_write_blk64)
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(unsigned long long block, int count, errcode_t err);
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extern void (*test_io_cb_set_blksize)
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(int blksize, errcode_t err);
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#endif /* _EXT2FS_EXT2_IO_H */
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