Explain to users that they may want to kldload aio.

Move Xref sections.

Submitted by: Craig Rodrigues <rodrigc@attbi.com>

7 files changed, 175 insertions, 22 deletions

diff --git a/lib/libc/sys/aio_cancel.2 b/lib/libc/sys/aio_cancel.2
index 832356b..a7003cf 100644
--- a/lib/libc/sys/aio_cancel.2
+++ b/lib/libc/sys/aio_cancel.2
@@ -72,12 +72,6 @@ checked with
 .It Bq Dv AIO_ALLDONE
 All of the requests meeting the criteria have finished.
 .El
-.Sh SEE ALSO
-.Xr aio_error 2 ,
-.Xr aio_read 2 ,
-.Xr aio_return 2 ,
-.Xr aio_suspend 2 ,
-.Xr aio_write 2
 .Sh ERRORS
 An error return from
 .Fn aio_cancel
@@ -87,6 +81,32 @@ indicates:
 .Fa fildes
 is an invalid file descriptor.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
+.Sh SEE ALSO
+.Xr aio_error 2 ,
+.Xr aio_read 2 ,
+.Xr aio_return 2 ,
+.Xr aio_suspend 2 ,
+.Xr aio_write 2 ,
+.Xr config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 The
 .Fn aio_cancel
diff --git a/lib/libc/sys/aio_error.2 b/lib/libc/sys/aio_error.2
index 4347758..3881a2a 100644
--- a/lib/libc/sys/aio_error.2
+++ b/lib/libc/sys/aio_error.2
@@ -70,6 +70,23 @@ function will fail if:
 .Fa iocb
 does not reference an outstanding asynchronous I/O request.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_read 2 ,
@@ -79,6 +96,9 @@ does not reference an outstanding asynchronous I/O request.
 .Xr fsync 2 ,
 .Xr read 2 ,
 .Xr write 2
+.Xr config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 .Fn aio_error
 is expected to conform to the
diff --git a/lib/libc/sys/aio_read.2 b/lib/libc/sys/aio_read.2
index b57de3e..ea542fb 100644
--- a/lib/libc/sys/aio_read.2
+++ b/lib/libc/sys/aio_read.2
@@ -179,6 +179,33 @@ The offset
 .Fa iocb->aio_offset
 would be invalid.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
+.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 config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 The
 .Fn aio_read
diff --git a/lib/libc/sys/aio_return.2 b/lib/libc/sys/aio_return.2
index 2d50143..8477cee 100644
--- a/lib/libc/sys/aio_return.2
+++ b/lib/libc/sys/aio_return.2
@@ -63,15 +63,6 @@ returns
 and sets
 .Dv errno
 to indicate the error condition.
-.Sh SEE ALSO
-.Xr aio_cancel 2 ,
-.Xr aio_error 2 ,
-.Xr aio_read 2 ,
-.Xr aio_suspend 2 ,
-.Xr aio_write 2 ,
-.Xr fsync 2 ,
-.Xr read 2 ,
-.Xr write 2
 .Sh ERRORS
 The
 .Fn aio_return
@@ -81,6 +72,35 @@ function will fail if:
 .Fa iocb
 does not reference an outstanding asynchronous I/O request.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
+.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 config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 .Fn aio_return
 is expected to conform to the
diff --git a/lib/libc/sys/aio_suspend.2 b/lib/libc/sys/aio_suspend.2
index d208d91..4c52230 100644
--- a/lib/libc/sys/aio_suspend.2
+++ b/lib/libc/sys/aio_suspend.2
@@ -67,12 +67,6 @@ completed,
 returns 0.  Otherwise it returns -1 and sets
 .Va errno
 to indicate the error, as enumerated below.
-.Sh SEE ALSO
-.Xr aio_cancel 2 ,
-.Xr aio_error 2 ,
-.Xr aio_read 2 ,
-.Xr aio_suspend 2 ,
-.Xr aio_write 2
 .Sh ERRORS
 The
 .Fn aio_suspend
@@ -91,6 +85,32 @@ valid.
 .It Bq Er EINTR
 the suspend was interrupted by a signal.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
+.Sh SEE ALSO
+.Xr aio_cancel 2 ,
+.Xr aio_error 2 ,
+.Xr aio_return 2 ,
+.Xr aio_waitcomplete 2 ,
+.Xr aio_write 2 ,
+.Xr config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 .Fn aio_suspend
 is expected to conform to the
diff --git a/lib/libc/sys/aio_waitcomplete.2 b/lib/libc/sys/aio_waitcomplete.2
index de01283..7d167dd 100644
--- a/lib/libc/sys/aio_waitcomplete.2
+++ b/lib/libc/sys/aio_waitcomplete.2
@@ -108,6 +108,23 @@ asynchronous I/O requests completed.
 The specified time limit expired before any asynchronous I/O requests
 completed.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
 .Sh SEE ALSO
 .Xr aio_cancel 2 ,
 .Xr aio_error 2 ,
@@ -117,7 +134,10 @@ completed.
 .Xr aio_write 2 ,
 .Xr fsync 2 ,
 .Xr read 2 ,
-.Xr write 2
+.Xr write 2 ,
+.Xr config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 The
 .Fn aio_waitcomplete
diff --git a/lib/libc/sys/aio_write.2 b/lib/libc/sys/aio_write.2
index ae1f10a..3ca9e1f 100644
--- a/lib/libc/sys/aio_write.2
+++ b/lib/libc/sys/aio_write.2
@@ -173,6 +173,32 @@ The offset
 .Fa iocb->aio_offset
 would be invalid.
 .El
+.Sh KERNEL OPTIONS
+The following kernel configuration option
+(see
+.Xr config 8 )
+is required:
+.Pp
+.Dl "options VFS_AIO"
+.Pp
+If you do not want AIO support included in the kernel, but
+want to use it occasionally, do not add the
+.Dv VFS_AIO
+option.  Instead, load the
+.Nm aio
+module as desired:
+.Pp
+.Dl kldload aio
+.Pp
+.Sh SEE ALSO
+.Xr aio_cancel 2 ,
+.Xr aio_error 2 ,
+.Xr aio_return 2 ,
+.Xr aio_suspend 2 ,
+.Xr aio_waitcomplete 2 ,
+.Xr config 8 ,
+.Xr kldload 8 ,
+.Xr kldunload 8
 .Sh STANDARDS
 .Fn aio_write
 is expected to conform to the