Edit File: ext2_io.h
/* * io.h --- the I/O manager abstraction * * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Library * General Public License, version 2. * %End-Header% */ #ifndef _EXT2FS_EXT2_IO_H #define _EXT2FS_EXT2_IO_H #include <ext2fs/ext2_types.h> /* * ext2_loff_t is defined here since unix_io.c needs it. */ #if defined(__GNUC__) || defined(HAS_LONG_LONG) typedef long long ext2_loff_t; #else typedef long ext2_loff_t; #endif /* llseek.c */ ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); typedef struct struct_io_manager *io_manager; typedef struct struct_io_channel *io_channel; typedef struct struct_io_stats *io_stats; #define CHANNEL_FLAGS_WRITETHROUGH 0x01 #define CHANNEL_FLAGS_DISCARD_ZEROES 0x02 #define CHANNEL_FLAGS_BLOCK_DEVICE 0x04 #define io_channel_discard_zeroes_data(i) (i->flags & CHANNEL_FLAGS_DISCARD_ZEROES) struct struct_io_channel { errcode_t magic; io_manager manager; char *name; int block_size; errcode_t (*read_error)(io_channel channel, unsigned long block, int count, void *data, size_t size, int actual_bytes_read, errcode_t error); errcode_t (*write_error)(io_channel channel, unsigned long block, int count, const void *data, size_t size, int actual_bytes_written, errcode_t error); int refcount; int flags; long reserved[14]; void *private_data; void *app_data; int align; }; struct struct_io_stats { int num_fields; int reserved; unsigned long long bytes_read; unsigned long long bytes_written; }; struct struct_io_manager { errcode_t magic; const char *name; errcode_t (*open)(const char *name, int flags, io_channel *channel); errcode_t (*close)(io_channel channel); errcode_t (*set_blksize)(io_channel channel, int blksize); errcode_t (*read_blk)(io_channel channel, unsigned long block, int count, void *data); errcode_t (*write_blk)(io_channel channel, unsigned long block, int count, const void *data); errcode_t (*flush)(io_channel channel); errcode_t (*write_byte)(io_channel channel, unsigned long offset, int count, const void *data); errcode_t (*set_option)(io_channel channel, const char *option, const char *arg); errcode_t (*get_stats)(io_channel channel, io_stats *io_stats); errcode_t (*read_blk64)(io_channel channel, unsigned long long block, int count, void *data); errcode_t (*write_blk64)(io_channel channel, unsigned long long block, int count, const void *data); errcode_t (*discard)(io_channel channel, unsigned long long block, unsigned long long count); errcode_t (*cache_readahead)(io_channel channel, unsigned long long block, unsigned long long count); errcode_t (*zeroout)(io_channel channel, unsigned long long block, unsigned long long count); long reserved[14]; }; #define IO_FLAG_RW 0x0001 #define IO_FLAG_EXCLUSIVE 0x0002 #define IO_FLAG_DIRECT_IO 0x0004 #define IO_FLAG_FORCE_BOUNCE 0x0008 /* * Convenience functions.... */ #define io_channel_close(c) ((c)->manager->close((c))) #define io_channel_set_blksize(c,s) ((c)->manager->set_blksize((c),s)) #define io_channel_read_blk(c,b,n,d) ((c)->manager->read_blk((c),b,n,d)) #define io_channel_write_blk(c,b,n,d) ((c)->manager->write_blk((c),b,n,d)) #define io_channel_flush(c) ((c)->manager->flush((c))) #define io_channel_bumpcount(c) ((c)->refcount++) /* io_manager.c */ extern errcode_t io_channel_set_options(io_channel channel, const char *options); extern errcode_t io_channel_write_byte(io_channel channel, unsigned long offset, int count, const void *data); extern errcode_t io_channel_read_blk64(io_channel channel, unsigned long long block, int count, void *data); extern errcode_t io_channel_write_blk64(io_channel channel, unsigned long long block, int count, const void *data); extern errcode_t io_channel_discard(io_channel channel, unsigned long long block, unsigned long long count); extern errcode_t io_channel_zeroout(io_channel channel, unsigned long long block, unsigned long long count); extern errcode_t io_channel_alloc_buf(io_channel channel, int count, void *ptr); extern errcode_t io_channel_cache_readahead(io_channel io, unsigned long long block, unsigned long long count); /* unix_io.c */ extern io_manager unix_io_manager; extern io_manager unixfd_io_manager; /* sparse_io.c */ extern io_manager sparse_io_manager; extern io_manager sparsefd_io_manager; /* undo_io.c */ extern io_manager undo_io_manager; extern errcode_t set_undo_io_backing_manager(io_manager manager); extern errcode_t set_undo_io_backup_file(char *file_name); /* test_io.c */ extern io_manager test_io_manager, test_io_backing_manager; extern void (*test_io_cb_read_blk) (unsigned long block, int count, errcode_t err); extern void (*test_io_cb_write_blk) (unsigned long block, int count, errcode_t err); extern void (*test_io_cb_read_blk64) (unsigned long long block, int count, errcode_t err); extern void (*test_io_cb_write_blk64) (unsigned long long block, int count, errcode_t err); extern void (*test_io_cb_set_blksize) (int blksize, errcode_t err); #endif /* _EXT2FS_EXT2_IO_H */
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