aio_fsync(2) [freebsd man page]
AIO_FSYNC(2) BSD System Calls Manual AIO_FSYNC(2) NAME
aio_fsync -- asynchronous file synchronization (REALTIME) LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <aio.h> int aio_fsync(int op, struct aiocb *iocb); DESCRIPTION
The aio_fsync() system call allows the calling process to move all modified data associated with the descriptor iocb->aio_fildes to a perma- nent 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. The op argument can only be set to O_SYNC to cause all currently queued I/O operations to be completed as if by a call to fsync(2). 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 iocb->aio_reqprio. The iocb 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. If the request could not be enqueued (generally due to invalid arguments), the call returns without having enqueued the request. 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 indi- cate the error. ERRORS
The aio_fsync() system call will fail if: [EAGAIN] The request was not queued because of system resource limitations. [ENOSYS] The aio_fsync() system call is not supported. [EINVAL] A value of the op argument is not set to O_SYNC. 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 iocb->aio_fildes argument is not a valid descriptor. [EINVAL] This implementation does not support synchronized I/O for this file. If the request is successfully enqueued, but subsequently cancelled or an error occurs, the value returned by the aio_return() system call is per the read(2) and write(2) system calls, and the value returned by the aio_error() system call is one of the error returns from the read(2) or write(2) system calls. SEE ALSO
aio_cancel(2), aio_error(2), aio_read(2), aio_return(2), aio_suspend(2), aio_waitcomplete(2), aio_write(2), fsync(2), siginfo(3), aio(4) STANDARDS
The aio_fsync() system call is expected to conform to the IEEE Std 1003.1 (``POSIX.1'') standard. HISTORY
The aio_fsync() system call first appeared in FreeBSD 7.0. BSD
December 27, 2013 BSD
Check Out this Related Man Page
aio_fsync(2) System Calls Manual aio_fsync(2) NAME
aio_fsync - Asynchronously writes changes in a file to permanent storage LIBRARY
Asynchronous I/O Library (libaio, libaio_raw) SYNOPSIS
#include <aio.h> int aio_fsync ( int op, struct aiocb *aiocbp ); PARAMETERS
op Specifies file or data synchronization. aiocbp Specifies a pointer to an aiocb structure. This function uses only the aio_fildes and aio_sigevent fields of the aiocbp control block. DESCRIPTION
The aio_fsync function asynchronously causes system buffers containing a file's modified data to be written to permanent storage. All mod- ified data in the file indicated by the file descriptor in the aio_fildes member of the aiocb structure referenced by the aiocbp argument is forced to the synchronized I/O completion state. The aio_fsync function returns when the synchronization request has been initiated or queued, even when data cannot be synchronized immedi- ately. If op is O_DSYNC, all currently queued I/O operations are completed as if by a call to fdatasync. If op is O_SYNC, all currently queued I/O operations are completed as if by a call to fsync. If the aio_fsync function fails, outstanding I/O operations are not guaranteed to have been completed. If aio_fsync succeeds, only the I/O that was queued at the time of the call is guaranteed to be synchronized; the completion of subsequent I/O is not guaranteed. The aiocbp value may be used as an argument to the aio_error and aio_return functions to determine the error or return status of the asyn- chronous operation while it is proceeding. When the request is queued, the error status for the operation is [EINPROGRESS]. When all data has been synchronized, the error status is set to reflect the success or failure of the operation. The aio_sigevent member of the aiocb structure defines the signal to be generated upon completion of the operation. If aio_sigevent.sigev_notify equals SIGEV_SIGNAL and aio_sigevent.sigev_signo is non-zero, a signal will be generated when all operations have achieved synchronized I/O completion. RETURN VALUES
Upon successful completion, the aio_fsync function returns a value of 0 (zero). If the aio_fsync function fails, a value of -1 is returned and errno is set to indicate the error. If aio_fsync fails, outstanding I/O operations are not guaranteed to have been completed. ERRORS
If the aio_fsync function fails, errno may be set to one of the following values: [EAGAIN] The requested asynchronous operation was not queued due to temporary resource limitations. [EBADF] The aio_fildes member of the aiocb structure is not a valid file descriptor. [EINVAL] A value of op other than O_DSYNC or O_SYNC was specified. If any queued I/O operations fail, the aio_fsync function returns error conditions defined for read and write. The error is returned in the error status for the asynchronous fsync operation, which can be retrieved using aio_error. RELATED INFORMATION
Functions: fdatasync(2), fcntl(2), fsync(2), open(2), read(2), sync(2), write(2) Guide to Realtime Programming delim off aio_fsync(2)