diff --git a/lib/libsys/aio_cancel.2 b/lib/libsys/aio_cancel.2
index 928a8b325e5f..42d074054716 100644
--- a/lib/libsys/aio_cancel.2
+++ b/lib/libsys/aio_cancel.2
@@ -1,122 +1,115 @@
 .\" Copyright (c) 1999 Softweyr LLC.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd January 19, 2000
 .Dt AIO_CANCEL 2
 .Os
 .Sh NAME
 .Nm aio_cancel
 .Nd cancel an outstanding asynchronous I/O operation (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_cancel "int fildes" "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_cancel
 system call cancels the outstanding asynchronous
 I/O request for the file descriptor specified in
 .Fa fildes .
 If
 .Fa iocb
 is specified, only that specific asynchronous I/O request is cancelled.
 .Pp
 Normal asynchronous notification occurs for cancelled requests.
 Requests complete with an error result of
 .Er ECANCELED .
 .Sh RESTRICTIONS
 The
 .Fn aio_cancel
 system call does not cancel asynchronous I/O requests for raw disk devices.
 The
 .Fn aio_cancel
 system call will always return
 .Dv AIO_NOTCANCELED
 for file descriptors associated with raw disk devices.
 .Sh RETURN VALUES
 The
 .Fn aio_cancel
 system call returns -1 to indicate an error, or one of the following:
 .Bl -tag -width Dv
 .It Bq Dv AIO_CANCELED
 All outstanding requests meeting the criteria specified were cancelled.
 .It Bq Dv AIO_NOTCANCELED
 Some requests were not cancelled, status for the requests should be
 checked with
 .Xr aio_error 2 .
 .It Bq Dv AIO_ALLDONE
 All of the requests meeting the criteria have finished.
 .El
 .Sh ERRORS
 An error return from
 .Fn aio_cancel
 indicates:
 .Bl -tag -width Er
 .It Bq Er EBADF
 The
 .Fa fildes
 argument
 is an invalid file descriptor.
-.It Bq Er ENOSYS
-The
-.Fn aio_cancel
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .El
 .Sh SEE ALSO
 .Xr aio_error 2 ,
 .Xr aio_read 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_write 2 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_cancel
 system call is expected to conform to the
 .St -p1003.1
 standard.
 .Sh HISTORY
 The
 .Fn aio_cancel
 system call first appeared in
 .Fx 3.0 .
 The first functional implementation of
 .Fn aio_cancel
 appeared in
 .Fx 4.0 .
 .Sh AUTHORS
 .An -nosplit
 This
 manual page was originally written by
 .An Wes Peters Aq Mt wes@softweyr.com .
 .An Christopher M Sedore Aq Mt cmsedore@maxwell.syr.edu
 updated it when
 .Fn aio_cancel
 was implemented for
 .Fx 4.0 .
diff --git a/lib/libsys/aio_error.2 b/lib/libsys/aio_error.2
index 2579d2f33052..69eb7cd90ee2 100644
--- a/lib/libsys/aio_error.2
+++ b/lib/libsys/aio_error.2
@@ -1,110 +1,103 @@
 .\" Copyright (c) 1999 Softweyr LLC.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd January 2, 2021
 .Dt AIO_ERROR 2
 .Os
 .Sh NAME
 .Nm aio_error
 .Nd retrieve error status of asynchronous I/O operation (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_error "const struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_error
 system call returns the error status of the asynchronous I/O request
 associated with the structure pointed to by
 .Fa iocb .
 .Sh RETURN VALUES
 If the asynchronous I/O request has completed successfully,
 .Fn aio_error
 returns 0.
 If the request has not yet completed,
 .Er EINPROGRESS
 is returned.
 If the request has completed unsuccessfully the error
 status is returned as described in
 .Xr read 2 ,
 .Xr readv 2 ,
 .Xr write 2 ,
 .Xr writev 2 ,
 or
 .Xr fsync 2 .
 On failure,
 .Fn aio_error
 returns
 .Dv -1
 and sets
 .Dv errno
 to indicate the error condition.
 .Sh ERRORS
 The
 .Fn aio_error
 system call will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL
 The
 .Fa iocb
 argument
 does not reference an outstanding asynchronous I/O request.
-.It Bq Er ENOSYS
-The
-.Fn aio_error
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .El
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_read 2 ,
 .Xr aio_readv 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_write 2 ,
 .Xr aio_writev 2 ,
 .Xr fsync 2 ,
 .Xr read 2 ,
 .Xr write 2 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_error
 system call
 is expected to conform to the
 .St -p1003.1
 standard.
 .Sh HISTORY
 The
 .Fn aio_error
 system call first appeared in
 .Fx 3.0 .
 .Sh AUTHORS
 This
 manual page was written by
 .An Wes Peters Aq Mt wes@softweyr.com .
diff --git a/lib/libsys/aio_fsync.2 b/lib/libsys/aio_fsync.2
index 0b863773eaf2..46fc5d95bcfd 100644
--- a/lib/libsys/aio_fsync.2
+++ b/lib/libsys/aio_fsync.2
@@ -1,188 +1,181 @@
 .\" Copyright (c) 2013 Sergey Kandaurov
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd November 15, 2023
 .Dt AIO_FSYNC 2
 .Os
 .Sh NAME
 .Nm aio_fsync
 .Nd asynchronous file synchronization (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_fsync "int op" "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_fsync
 system call allows the calling process to move all modified data
 associated with the descriptor
 .Fa iocb->aio_fildes
 to a permanent 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.
 .Pp
 The
 .Fa op
 argument can be set to
 .Dv O_SYNC
 to cause all currently queued I/O operations to be completed
 as if by a call to
 .Xr fsync 2 ,
 or
 .Dv O_DSYNC
 for the behavior of
 .Xr fdatasync 2 .
 .Pp
 The
 .Fa iocb
 pointer may be subsequently used as an argument to
 .Fn aio_return
 and
 .Fn aio_error
 in order to determine return or error status for the enqueued operation
 while it is in progress.
 .Pp
 If the request could not be enqueued (generally due to invalid arguments),
 the call returns without having enqueued the request.
 .Pp
 The
 .Fa iocb->aio_sigevent
 structure can be used to request notification of the operation's
 completion as described in
 .Xr aio 4 .
 .Sh RESTRICTIONS
 The Asynchronous I/O Control Block structure pointed to by
 .Fa iocb
 must remain valid until the
 operation has completed.
 .Pp
 The asynchronous I/O control buffer
 .Fa iocb
 should be zeroed before the
 .Fn aio_fsync
 call to avoid passing bogus context information to the kernel.
 .Pp
 Modification of the Asynchronous I/O Control Block structure is not allowed
 while the request is queued.
 .Sh RETURN VALUES
 .Rv -std aio_fsync
 .Sh ERRORS
 The
 .Fn aio_fsync
 system call will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The request was not queued because of system resource limitations.
 .It Bq Er EINVAL
 The asynchronous notification method in
 .Fa iocb->aio_sigevent.sigev_notify
 is invalid or not supported.
 .It Bq Er EOPNOTSUPP
 Asynchronous file synchronization operations on the file descriptor
 .Fa iocb->aio_fildes
 are unsafe and unsafe asynchronous I/O operations are disabled.
 .It Bq Er EINVAL
 A value of the
 .Fa op
 argument is not set to
 .Dv O_SYNC
 or
 .Dv O_DSYNC .
 .El
 .Pp
 The following conditions may be synchronously detected when the
 .Fn aio_fsync
 system call is made, or asynchronously, at any time thereafter.
 If they are detected at call time,
 .Fn aio_fsync
 returns -1 and sets
 .Va errno
 appropriately; otherwise the
 .Fn aio_return
 system call must be called, and will return -1, and
 .Fn aio_error
 must be called to determine the actual value that would have been
 returned in
 .Va errno .
 .Bl -tag -width Er
 .It Bq Er EBADF
 The
 .Fa iocb->aio_fildes
 argument
 is not a valid descriptor.
 .It Bq Er EINVAL
 This implementation does not support synchronized I/O for this file.
-.It Bq Er ENOSYS
-The
-.Fn aio_fsync
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .El
 .Pp
 If the request is successfully enqueued, but subsequently cancelled
 or an error occurs, the value returned by the
 .Fn aio_return
 system call is per the
 .Xr read 2
 and
 .Xr write 2
 system calls, and the value returned by the
 .Fn aio_error
 system call is one of the error returns from the
 .Xr read 2
 or
 .Xr write 2
 system calls.
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_read 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_waitcomplete 2 ,
 .Xr aio_write 2 ,
 .Xr fsync 2 ,
 .Xr sigevent 3 ,
 .Xr siginfo 3 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_fsync
 system call is expected to conform to the
 .St -p1003.1
 standard.
 .Sh HISTORY
 The
 .Fn aio_fsync
 system call first appeared in
 .Fx 7.0 .
 The
 .Dv O_DSYNC
 option appeared in
 .Fx 13.0 .
diff --git a/lib/libsys/aio_mlock.2 b/lib/libsys/aio_mlock.2
index f89ad10936aa..02d54304c631 100644
--- a/lib/libsys/aio_mlock.2
+++ b/lib/libsys/aio_mlock.2
@@ -1,143 +1,136 @@
 .\" Copyright (c) 2013 Gleb Smirnoff <glebius@FreeBSD.org>
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd August 19, 2016
 .Dt AIO_MLOCK 2
 .Os
 .Sh NAME
 .Nm aio_mlock
 .Nd asynchronous
 .Xr mlock 2
 operation
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_mlock "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_mlock
 system call allows the calling process to lock into memory the
 physical pages associated with the virtual address range starting at
 .Fa iocb->aio_buf
 for
 .Fa iocb->aio_nbytes
 bytes.
 The call returns immediately after the locking request has
 been enqueued; the operation may or may not have completed at the time
 the call returns.
 .Pp
 The
 .Fa iocb
 pointer may be subsequently used as an argument to
 .Fn aio_return
 and
 .Fn aio_error
 in order to determine return or error status for the enqueued operation
 while it is in progress.
 .Pp
 If the request could not be enqueued (generally due to
 .Xr aio 4
 limits),
 then the call returns without having enqueued the request.
 .Pp
 The
 .Fa iocb->aio_sigevent
 structure can be used to request notification of the operation's
 completion as described in
 .Xr aio 4 .
 .Sh RESTRICTIONS
 The Asynchronous I/O Control Block structure pointed to by
 .Fa iocb
 and the buffer that the
 .Fa iocb->aio_buf
 member of that structure references must remain valid until the
 operation has completed.
 .Pp
 The asynchronous I/O control buffer
 .Fa iocb
 should be zeroed before the
 .Fn aio_mlock
 call to avoid passing bogus context information to the kernel.
 .Pp
 Modifications of the Asynchronous I/O Control Block structure or the
 memory mapping described by the virtual address range are not allowed
 while the request is queued.
 .Sh RETURN VALUES
 .Rv -std aio_mlock
 .Sh ERRORS
 The
 .Fn aio_mlock
 system call will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The request was not queued because of system resource limitations.
 .It Bq Er EINVAL
 The asynchronous notification method in
 .Fa iocb->aio_sigevent.sigev_notify
 is invalid or not supported.
-.It Bq Er ENOSYS
-The
-.Fn aio_mlock
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .El
 .Pp
 If the request is successfully enqueued, but subsequently cancelled
 or an error occurs, the value returned by the
 .Fn aio_return
 system call is per the
 .Xr mlock 2
 system call, and the value returned by the
 .Fn aio_error
 system call is one of the error returns from the
 .Xr mlock 2
 system call, or
 .Er ECANCELED
 if the request was explicitly cancelled via a call to
 .Fn aio_cancel .
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_return 2 ,
 .Xr mlock 2 ,
 .Xr sigevent 3 ,
 .Xr aio 4
 .Sh PORTABILITY
 The
 .Fn aio_mlock
 system call is a
 .Fx
 extension, and should not be used in portable code.
 .Sh HISTORY
 The
 .Fn aio_mlock
 system call first appeared in
 .Fx 10.0 .
 .Sh AUTHORS
 The system call was introduced by
 .An Gleb Smirnoff Aq Mt glebius@FreeBSD.org .
diff --git a/lib/libsys/aio_read.2 b/lib/libsys/aio_read.2
index 811d0b234168..f7d8cdfd71b1 100644
--- a/lib/libsys/aio_read.2
+++ b/lib/libsys/aio_read.2
@@ -1,297 +1,290 @@
 .\" Copyright (c) 1998 Terry Lambert
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd February 1, 2024
 .Dt AIO_READ 2
 .Os
 .Sh NAME
 .Nm aio_read ,
 .Nm aio_read2 ,
 .Nm aio_readv
 .Nd asynchronous read from a file (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_read "struct aiocb *iocb"
 .Ft int
 .Fn aio_read2 "struct aiocb *iocb" "int flags"
 .In sys/uio.h
 .Ft int
 .Fn aio_readv "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_read ,
 .Fn aio_read2
 and
 .Fn aio_readv
 system calls allow the calling process to read
 from the descriptor
 .Fa iocb->aio_fildes .
 The syscalls return immediately after the read request has
 been enqueued to the descriptor; the read may or may not have
 completed at the time the call returns.
 .Pp
 For the
 .Fn aio_read
 and
 .Fn aio_readv
 calls, the read begins at the offset
 .Fa iocb->aio_offset .
 .Pp
 The
 .Fn aio_read
 call will read
 .Fa iocb->aio_nbytes
 into the buffer pointed to by
 .Fa iocb->aio_buf ,
 whereas
 .Fn aio_readv
 reads the data into the
 .Fa iocb->aio_iovcnt
 buffers specified by the members of the
 .Fa iocb->aio_iov
 array.
 For
 .Fn aio_readv
 the
 .Fa iovec
 structure is defined in
 .Xr readv 2 .
 .Pp
 The
 .Fn aio_read2
 call takes the
 .Fa flags
 argument.
 If
 .Fa flags
 is passed as zero, the call behaves identically to
 .Fn aio_read .
 The following flags can be specified by logical or:
 .Bl -tag -width AIO_OP2_VECTORED
 .It AIO_OP2_FOFFSET
 The read occurs at the file descriptor offset,
 which is advanced by the operation as done by the
 .Xr read 2
 syscall.
 The
 .Fa iocb->aio_offset
 field is ignored.
 .It AIO_OP2_VECTORED
 Similar to
 .Fn aio_readv ,
 the read buffers are specified by the
 .Fa aiocb->aio_iov
 array.
 .El
 .Pp
 The
 .Fa iocb
 pointer may be subsequently used as an argument to
 .Fn aio_return
 and
 .Fn aio_error
 in order to determine return or error status for the enqueued operation
 while it is in progress.
 .Pp
 If the request could not be enqueued (generally due to invalid arguments),
 then the call returns without having enqueued the request.
 .Pp
 If the request is successfully enqueued, the value of
 .Fa iocb->aio_offset
 can be modified during the request as context, so this value must
 not be referenced after the request is enqueued.
 .Pp
 The
 .Fa iocb->aio_sigevent
 structure can be used to request notification of the operation's
 completion as described in
 .Xr aio 4 .
 .Sh RESTRICTIONS
 The Asynchronous I/O Control Block structure pointed to by
 .Fa iocb
 and the buffer that the
 .Fa iocb->aio_buf
 member of that structure references must remain valid until the
 operation has completed.
 .Pp
 The asynchronous I/O control buffer
 .Fa iocb
 should be zeroed before the system
 calls to avoid passing bogus context information to the kernel.
 .Pp
 Modifications of the Asynchronous I/O Control Block structure or the
 buffer contents are not allowed while the request is queued.
 .Pp
 If the file offset in
 .Fa iocb->aio_offset
 is past the offset maximum for
 .Fa iocb->aio_fildes ,
 no I/O will occur.
 .Sh RETURN VALUES
 .Rv -std aio_read aio_read2 aio_readv
 .Sh DIAGNOSTICS
 None.
 .Sh ERRORS
 The
 .Fn aio_read ,
 .Fn aio_read2 ,
 and
 .Fn aio_readv
 system calls will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The request was not queued because of system resource limitations.
 .It Bq Er EFAULT
 Part of
 .Fa aio_iov
 points outside the process's allocated address space.
 .It Bq Er EINVAL
 The asynchronous notification method in
 .Fa iocb->aio_sigevent.sigev_notify
 is invalid or not supported.
-.It Bq Er ENOSYS
-The
-.Fn aio_read
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .It Bq Er EOPNOTSUPP
 Asynchronous read operations on the file descriptor
 .Fa iocb->aio_fildes
 are unsafe and unsafe asynchronous I/O operations are disabled.
 .El
 .Pp
 The following conditions may be synchronously detected when the
 .Fn aio_read
 or
 .Fn aio_readv
 system call is made, or asynchronously, at any time thereafter.
 If they
 are detected at call time,
 The calls return -1 and set
 .Va errno
 appropriately; otherwise the
 .Fn aio_return
 system call must be called, and will return -1, and
 .Fn aio_error
 must be called to determine the actual value that would have been
 returned in
 .Va errno .
 .Bl -tag -width Er
 .It Bq Er EBADF
 The
 .Fa iocb->aio_fildes
 argument
 is invalid.
 .It Bq Er EINVAL
 The offset
 .Fa iocb->aio_offset
 is not valid, the priority specified by
 .Fa iocb->aio_reqprio
 is not a valid priority, or the number of bytes specified by
 .Fa iocb->aio_nbytes
 is not valid.
 .It Bq Er EOVERFLOW
 The file is a regular file,
 .Fa iocb->aio_nbytes
 is greater than zero, the starting offset in
 .Fa iocb->aio_offset
 is before the end of the file, but is at or beyond the
 .Fa iocb->aio_fildes
 offset maximum.
 .El
 .Pp
 If the request is successfully enqueued, but subsequently cancelled
 or an error occurs, the value returned by the
 .Fn aio_return
 system call is per the
 .Xr read 2
 system call, and the value returned by the
 .Fn aio_error
 system call is either one of the error returns from the
 .Xr read 2
 system call, or one of:
 .Bl -tag -width Er
 .It Bq Er EBADF
 The
 .Fa iocb->aio_fildes
 argument
 is invalid for reading.
 .It Bq Er ECANCELED
 The request was explicitly cancelled via a call to
 .Fn aio_cancel .
 .It Bq Er EINVAL
 The offset
 .Fa iocb->aio_offset
 would be invalid.
 .El
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_waitcomplete 2 ,
 .Xr aio_write 2 ,
 .Xr sigevent 3 ,
 .Xr siginfo 3 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_read
 system call is expected to conform to the
 .St -p1003.1
 standard.
 The
 .Fn aio_read2
 and
 .Fn aio_readv
 system calls are
 .Fx
 extensions,
 and should not be used in portable code.
 .Sh HISTORY
 The
 .Fn aio_read
 system call first appeared in
 .Fx 3.0 .
 The
 .Fn aio_readv
 system call first appeared in
 .Fx 13.0 .
 The
 .Fn aio_read2
 system call first appeared in
 .Fx 14.1 .
 .Sh AUTHORS
 This
 manual page was written by
 .An Terry Lambert Aq Mt terry@whistle.com .
 .Sh BUGS
 Invalid information in
 .Fa iocb->_aiocb_private
 may confuse the kernel.
diff --git a/lib/libsys/aio_return.2 b/lib/libsys/aio_return.2
index 49e1abf201ec..499b85ef20d8 100644
--- a/lib/libsys/aio_return.2
+++ b/lib/libsys/aio_return.2
@@ -1,115 +1,108 @@
 .\" Copyright (c) 1999 Softweyr LLC.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd January 11, 2021
 .Dt AIO_RETURN 2
 .Os
 .Sh NAME
 .Nm aio_return
 .Nd retrieve return status of asynchronous I/O operation (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft ssize_t
 .Fn aio_return "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_return
 system call returns the final status of the asynchronous I/O request
 associated with the structure pointed to by
 .Fa iocb .
 .Pp
 The
 .Fn aio_return
 system call
 should only be called once, to obtain the final status of an asynchronous
 I/O operation once it has completed
 .Xr ( aio_error 2
 returns something other than
 .Er EINPROGRESS ) .
 .Sh RETURN VALUES
 If the asynchronous I/O request has completed, the status is returned
 as described in
 .Xr read 2 ,
 .Xr readv 2 ,
 .Xr write 2 ,
 .Xr writev 2 ,
 or
 .Xr fsync 2 .
 Otherwise,
 .Fn aio_return
 returns \-1 and sets
 .Va errno
 to indicate the error condition.
 .Sh ERRORS
 The
 .Fn aio_return
 system call will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL
 The
 .Fa iocb
 argument
 does not reference a completed asynchronous I/O request.
 .It Bq Er EINVAL
 The I/O operation was submitted with
 .Fn lio_listio ,
 and the value of the
 .Fa aio_lio_opcode
 is invalid.
-.It Bq Er ENOSYS
-The
-.Fn aio_return
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .El
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_waitcomplete 2 ,
 .Xr aio_write 2 ,
 .Xr fsync 2 ,
 .Xr read 2 ,
 .Xr write 2 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_return
 system call
 is expected to conform to the
 .St -p1003.1
 standard.
 .Sh HISTORY
 The
 .Fn aio_return
 system call first appeared in
 .Fx 3.0 .
 .Sh AUTHORS
 This
 manual page was written by
 .An Wes Peters Aq Mt wes@softweyr.com .
diff --git a/lib/libsys/aio_suspend.2 b/lib/libsys/aio_suspend.2
index ebc3c15d059f..c46b0292c34e 100644
--- a/lib/libsys/aio_suspend.2
+++ b/lib/libsys/aio_suspend.2
@@ -1,122 +1,115 @@
 .\" Copyright (c) 1999 Softweyr LLC.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd October 23, 2017
 .Dt AIO_SUSPEND 2
 .Os
 .Sh NAME
 .Nm aio_suspend
 .Nd suspend until asynchronous I/O operations or timeout complete (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_suspend "const struct aiocb *const iocbs[]" "int niocb" "const struct timespec *timeout"
 .Sh DESCRIPTION
 The
 .Fn aio_suspend
 system call suspends the calling process until at least one of the
 specified asynchronous I/O requests have completed, a signal is
 delivered, or the
 .Fa timeout
 has passed.
 .Pp
 The
 .Fa iocbs
 argument
 is an array of
 .Fa niocb
 pointers to asynchronous I/O requests.
 Array members containing
 null pointers will be silently ignored.
 .Pp
 If
 .Fa timeout
 is not a null pointer, it specifies a maximum interval to suspend.
 If
 .Fa timeout
 is a null pointer, the suspend blocks indefinitely.
 To effect a
 poll, the
 .Fa timeout
 should point to a zero-value timespec structure.
 .Sh RETURN VALUES
 If one or more of the specified asynchronous I/O requests have
 completed,
 .Fn aio_suspend
 returns 0.
 Otherwise it returns -1 and sets
 .Va errno
 to indicate the error, as enumerated below.
 .Sh ERRORS
 The
 .Fn aio_suspend
 system call will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 the
 .Fa timeout
 expired before any I/O requests completed.
 .It Bq Er EINVAL
 The
 .Fa iocbs
 argument
 contains more asynchronous I/O requests than the
 .Va vfs.aio.max_aio_queue_per_proc
 .Xr sysctl 8
 variable, or at least one of the requests is not valid.
 .It Bq Er EINTR
 the suspend was interrupted by a signal.
-.It Bq Er ENOSYS
-The
-.Fn aio_suspend
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .El
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_return 2 ,
 .Xr aio_waitcomplete 2 ,
 .Xr aio_write 2 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_suspend
 system call
 is expected to conform to the
 .St -p1003.1
 standard.
 .Sh HISTORY
 The
 .Fn aio_suspend
 system call first appeared in
 .Fx 3.0 .
 .Sh AUTHORS
 This
 manual page was written by
 .An Wes Peters Aq Mt wes@softweyr.com .
diff --git a/lib/libsys/aio_waitcomplete.2 b/lib/libsys/aio_waitcomplete.2
index 0a38155d7c75..f14e05abaaf0 100644
--- a/lib/libsys/aio_waitcomplete.2
+++ b/lib/libsys/aio_waitcomplete.2
@@ -1,142 +1,135 @@
 .\" Copyright (c) 1999 Christopher M Sedore.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd March 21, 2016
 .Dt AIO_WAITCOMPLETE 2
 .Os
 .Sh NAME
 .Nm aio_waitcomplete
 .Nd wait for the next completion of an aio request
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft ssize_t
 .Fn aio_waitcomplete "struct aiocb **iocbp" "struct timespec *timeout"
 .Sh DESCRIPTION
 The
 .Fn aio_waitcomplete
 system call waits for completion of an asynchronous I/O request.
 Upon completion,
 .Fn aio_waitcomplete
 returns the result of the function and sets
 .Fa iocbp
 to point to the structure associated with the original request.
 If an asynchronous I/O request is completed before
 .Fn aio_waitcomplete
 is called, it returns immediately with the completed request.
 .Pp
 If
 .Fa timeout
 is a non-NULL pointer, it specifies a maximum interval to wait for a
 asynchronous I/O request to complete.
 If
 .Fa timeout
 is a NULL pointer,
 .Fn aio_waitcomplete
 waits indefinitely.
 To effect a poll, the
 .Fa timeout
 argument should be non-NULL, pointing to a zero-valued timeval structure.
 .Pp
 The
 .Fn aio_waitcomplete
 system call also serves the function of
 .Fn aio_return ,
 thus
 .Fn aio_return
 should not be called for the control block returned in
 .Fa iocbp .
 .Sh RETURN VALUES
 If an asynchronous I/O request has completed,
 .Fa iocbp
 is set to point to the control block passed with the original request,
 and the status is returned as described in
 .Xr read 2 ,
 .Xr write 2 ,
 or
 .Xr fsync 2 .
 On failure,
 .Fn aio_waitcomplete
 returns
 .Dv -1 ,
 sets iocbp to
 .Dv NULL
 and sets
 .Va errno
 to indicate the error condition.
 .Sh ERRORS
 The
 .Fn aio_waitcomplete
 system call fails if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The process has not yet called
 .Fn aio_read
 or
 .Fn aio_write .
 .It Bq Er EINTR
 A signal was delivered before the timeout expired and before any
 asynchronous I/O requests completed.
 .It Bq Er EINVAL
 The specified time limit is invalid.
-.It Bq Er ENOSYS
-The
-.Fn aio_waitcomplete
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .It Bq Er EWOULDBLOCK
 .It Bq Er EINPROGRESS
 The specified time limit expired before any asynchronous I/O requests
 completed.
 .El
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_read 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_write 2 ,
 .Xr fsync 2 ,
 .Xr read 2 ,
 .Xr write 2 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_waitcomplete
 system call is a
 .Fx Ns -specific
 extension.
 .Sh HISTORY
 The
 .Fn aio_waitcomplete
 system call first appeared in
 .Fx 4.0 .
 .Sh AUTHORS
 The
 .Fn aio_waitcomplete
 system call and this manual page were written by
 .An Christopher M Sedore Aq Mt cmsedore@maxwell.syr.edu .
diff --git a/lib/libsys/aio_write.2 b/lib/libsys/aio_write.2
index a7108a87e378..875b24fa160a 100644
--- a/lib/libsys/aio_write.2
+++ b/lib/libsys/aio_write.2
@@ -1,298 +1,291 @@
 .\" Copyright (c) 1999 Softweyr LLC.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd February 1, 2024
 .Dt AIO_WRITE 2
 .Os
 .Sh NAME
 .Nm aio_write ,
 .Nm aio_write2 ,
 .Nm aio_writev
 .Nd asynchronous write to a file (REALTIME)
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In aio.h
 .Ft int
 .Fn aio_write "struct aiocb *iocb"
 .Ft int
 .Fn aio_write2 "struct aiocb *iocb" "int flags"
 .In sys/uio.h
 .Ft int
 .Fn aio_writev "struct aiocb *iocb"
 .Sh DESCRIPTION
 The
 .Fn aio_write ,
 .Fn aio_write2 ,
 and
 .Fn aio_writev
 system calls allow the calling process to write
 to the descriptor
 .Fa iocb->aio_fildes .
 The syscalls return immediately after the write request has been enqueued
 to the descriptor; the write may or may not have completed at the time
 the call returns.
 .Pp
 The
 .Fn aio_write
 call will write
 .Fa iocb->aio_nbytes
 from the buffer pointed to by
 .Fa iocb->aio_buf ,
 whereas
 .Fn aio_writev
 gathers the data from the
 .Fa iocb->aio_iovcnt
 buffers specified by the members of the
 .Fa iocb->aio_iov
 array.
 .Pp
 If the request could not be enqueued, generally due
 to invalid arguments, the call returns without having enqueued the
 request.
 .Pp
 For
 .Fn aio_writev
 the
 .Fa iovec
 structure is defined in
 .Xr writev 2 .
 .Pp
 If
 .Dv O_APPEND
 is set for
 .Fa iocb->aio_fildes ,
 write operations append to the file in the same order as the calls were
 made.
 If
 .Dv O_APPEND
 is not set for the file descriptor, the write operation for
 .Fn aio_write
 will occur at
 the absolute position from the beginning of the file plus
 .Fa iocb->aio_offset .
 .Pp
 The
 .Fn aio_write2
 call takes the
 .Fa flags
 argument.
 If
 .Fa flags
 is passed as zero, the call behaves identically to
 .Fn aio_write .
 The following flags can be specified by logical or:
 .Bl -tag -width AIO_OP2_VECTORED
 .It AIO_OP2_FOFFSET
 The write for non
 .Dv O_APPEND
 file descriptors occurs at the file descriptor offset,
 which is advanced by the operation as done by the
 .Xr write 2
 syscall.
 The
 .Fa iocb->aio_offset
 field is ignored.
 .It AIO_OP2_VECTORED
 Similar to
 .Fn aio_writev ,
 the write buffers are specified by the
 .Fa aiocb->aio_iov
 array.
 .El
 .Pp
 The
 .Fa iocb
 pointer may be subsequently used as an argument to
 .Fn aio_return
 and
 .Fn aio_error
 in order to determine return or error status for the enqueued operation
 while it is in progress.
 .Pp
 If the request is successfully enqueued, the value of
 .Fa iocb->aio_offset
 can be modified during the request as context, so this value must not
 be referenced after the request is enqueued.
 .Pp
 The
 .Fa iocb->aio_sigevent
 structure can be used to request notification of the operation's
 completion as described in
 .Xr aio 4 .
 .Sh RESTRICTIONS
 The Asynchronous I/O Control Block structure pointed to by
 .Fa iocb
 and the buffer that the
 .Fa iocb->aio_buf
 member of that structure references must remain valid until the
 operation has completed.
 .Pp
 The asynchronous I/O control buffer
 .Fa iocb
 should be zeroed before the
 system calls to avoid passing bogus context information to the kernel.
 .Pp
 Modifications of the Asynchronous I/O Control Block structure or the
 buffer contents are not allowed while the request is queued.
 .Pp
 If the file offset in
 .Fa iocb->aio_offset
 is past the offset maximum for
 .Fa iocb->aio_fildes ,
 no I/O will occur.
 .Sh RETURN VALUES
 .Rv -std aio_write aio_writev
 .Sh ERRORS
 The
 .Fn aio_write ,
 .Fn aio_write2 ,
 and
 .Fn aio_writev
 system calls will fail if:
 .Bl -tag -width Er
 .It Bq Er EAGAIN
 The request was not queued because of system resource limitations.
 .It Bq Er EFAULT
 Part of
 .Fa aio_iov
 points outside the process's allocated address space.
 .It Bq Er EINVAL
 The asynchronous notification method in
 .Fa iocb->aio_sigevent.sigev_notify
 is invalid or not supported.
-.It Bq Er ENOSYS
-The
-.Fn aio_write
-system call is not supported.
-This can occur if
-.Xr aio 4
-support is not present.
 .It Bq Er EOPNOTSUPP
 Asynchronous write operations on the file descriptor
 .Fa iocb->aio_fildes
 are unsafe and unsafe asynchronous I/O operations are disabled.
 .El
 .Pp
 The following conditions may be synchronously detected when the
 .Fn aio_write ,
 .Fn aio_write2 ,
 or
 .Fn aio_writev
 system call is made, or asynchronously, at any time thereafter.
 If they
 are detected at call time, the calls return -1 and set
 .Va errno
 appropriately; otherwise the
 .Fn aio_return
 system call must be called, and will return -1, and
 .Fn aio_error
 must be called to determine the actual value that would have been
 returned in
 .Va errno .
 .Bl -tag -width Er
 .It Bq Er EBADF
 The
 .Fa iocb->aio_fildes
 argument
 is invalid, or is not opened for writing.
 .It Bq Er EINVAL
 The offset
 .Fa iocb->aio_offset
 is not valid, the priority specified by
 .Fa iocb->aio_reqprio
 is not a valid priority, or the number of bytes specified by
 .Fa iocb->aio_nbytes
 is not valid.
 .El
 .Pp
 If the request is successfully enqueued, but subsequently canceled
 or an error occurs, the value returned by the
 .Fn aio_return
 system call is per the
 .Xr write 2
 system call, and the value returned by the
 .Fn aio_error
 system call is either one of the error returns from the
 .Xr write 2
 system call, or one of:
 .Bl -tag -width Er
 .It Bq Er EBADF
 The
 .Fa iocb->aio_fildes
 argument
 is invalid for writing.
 .It Bq Er ECANCELED
 The request was explicitly canceled via a call to
 .Fn aio_cancel .
 .It Bq Er EINVAL
 The offset
 .Fa iocb->aio_offset
 would be invalid.
 .El
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
 .Xr aio_return 2 ,
 .Xr aio_suspend 2 ,
 .Xr aio_waitcomplete 2 ,
 .Xr sigevent 3 ,
 .Xr siginfo 3 ,
 .Xr aio 4
 .Sh STANDARDS
 The
 .Fn aio_write
 system call
 is expected to conform to the
 .St -p1003.1
 standard.
 .Pp
 The
 .Fn aio_write2
 and
 .Fn aio_writev
 system calls are
 .Fx
 extensions,
 and should not be used in portable code.
 .Sh HISTORY
 The
 .Fn aio_write
 system call first appeared in
 .Fx 3.0 .
 The
 .Fn aio_writev
 system call first appeared in
 .Fx 13.0 .
 The
 .Fn aio_write2
 system call first appeared in
 .Fx 14.1 .
 .Sh AUTHORS
 This manual page was written by
 .An Wes Peters Aq Mt wes@softweyr.com .
 .Sh BUGS
 Invalid information in
 .Fa iocb->_aiocb_private
 may confuse the kernel.