NAME
aio_fsync —
asynchronous data
synchronization of file (REALTIME)
LIBRARY
POSIX Real-time Library (librt, -lrt)
SYNOPSIS
#include <aio.h>
int
aio_fsync(
int
op,
struct aiocb
*aiocbp);
DESCRIPTION
The
aio_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_DSYNC
nor O_SYNC
.
SEE ALSO
fcntl(2),
fdatasync(2),
fsync(2),
aio(3)
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.