1 .\" Copyright (c) 2013 Sergey Kandaurov
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .Nd asynchronous file synchronization (REALTIME)
38 .Fn aio_fsync "int op" "struct aiocb *iocb"
42 system call allows the calling process to move all modified data
43 associated with the descriptor
45 to a permanent storage device.
46 The call returns immediately after the synchronization request has been
47 enqueued to the descriptor; the synchronization may or may not have
48 completed at the time the call returns.
52 argument can be set to
54 to cause all currently queued I/O operations to be completed
62 If _POSIX_PRIORITIZED_IO is defined, and the descriptor supports it,
63 then the enqueued operation is submitted at a priority equal to that
64 of the calling process minus
65 .Fa iocb->aio_reqprio .
69 pointer may be subsequently used as an argument to
73 in order to determine return or error status for the enqueued operation
74 while it is in progress.
76 If the request could not be enqueued (generally due to invalid arguments),
77 the call returns without having enqueued the request.
80 .Fa iocb->aio_sigevent
81 structure can be used to request notification of the operation's
82 completion as described in
85 The Asynchronous I/O Control Block structure pointed to by
87 must remain valid until the
88 operation has completed.
90 The asynchronous I/O control buffer
92 should be zeroed before the
94 call to avoid passing bogus context information to the kernel.
96 Modification of the Asynchronous I/O Control Block structure is not allowed
97 while the request is queued.
103 system call will fail if:
106 The request was not queued because of system resource limitations.
108 The asynchronous notification method in
109 .Fa iocb->aio_sigevent.sigev_notify
110 is invalid or not supported.
112 Asynchronous file synchronization operations on the file descriptor
114 are unsafe and unsafe asynchronous I/O operations are disabled.
118 argument is not set to
124 The following conditions may be synchronously detected when the
126 system call is made, or asynchronously, at any time thereafter.
127 If they are detected at call time,
131 appropriately; otherwise the
133 system call must be called, and will return -1, and
135 must be called to determine the actual value that would have been
143 is not a valid descriptor.
145 This implementation does not support synchronized I/O for this file.
148 If the request is successfully enqueued, but subsequently cancelled
149 or an error occurs, the value returned by the
151 system call is per the
155 system calls, and the value returned by the
157 system call is one of the error returns from the
168 .Xr aio_waitcomplete 2 ,
177 system call is expected to conform to the
183 system call first appeared in