NAME
aio_fsync —
asynchronous data synchronization of
file (REALTIME)
LIBRARY
library “librt”
SYNOPSIS
#include
<aio.h>
int
aio_fsync(int
op, struct aiocb
*aiocbp);
DESCRIPTION
Theaio_fsync()
system call allows the calling process to force all modified data associated
with the file descriptor aiocbp->aio_fildes to be
flushed to the stable storage device. The call returns immediately after the
synchronization request has been enqueued to the descriptor; the
synchronization may or may not have completed at the time the call returns. If
the request could not be enqueued, generally due to invalid arguments, the
call returns without having enqueued the request.
The op argument could be
set only to O_DSYNC or
O_SYNC. If op is
O_DSYNC, then
aio_fsync()
does the same as a
fdatasync()
call, if O_SYNC, then the same as
fsync().
If _POSIX_PRIORITIZED_IO is defined, and
the descriptor supports it, then the enqueued operation is submitted at a
priority equal to that of the calling process minus
aiocbp->aio_reqprio.
The aiocbp pointer may be
subsequently used as an argument to
aio_return()
and
aio_error()
in order to determine return or error status for the enqueued operation
while it is in progress.
RETURN VALUES
The aio_fsync() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate the
error.
ERRORS
The aio_fsync() system call will fail
if:
- [
EAGAIN] - The request was not queued because of system resource limitations.
The following conditions may be synchronously detected when the
aio_fsync() system call is made, or asynchronously,
at any time thereafter. If they are detected at call time,
aio_fsync() returns -1 and sets
errno appropriately; otherwise the
aio_return() system call must be called, and will
return -1, and aio_error() must be called to
determine the actual value that would have been returned in
errno.
- [
EBADF] - The aiocbp->aio_fildes is invalid for writing.
- [
EINVAL] - This implementation does not support synchronized I/O for this file, or
the op argument is neither set to
O_DSYNCnorO_SYNC.
SEE ALSO
STANDARDS
The aio_fsync() system call is expected to
conform to the IEEE Std 1003.1-2001
(“POSIX.1”) standard.
HISTORY
The aio_fsync() system call first appeared
in NetBSD 5.0.