1.\" Copyright (c) 2008 Konstantin Belousov 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 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. 12.\" 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 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd September 8, 2008 28.Sh NAME 29.Nm dev_clone , 30.Nm drain_dev_clone_events 31.Nd eventhandler for name-based device cloning in devfs 32.Sh SYNOPSIS 33.In sys/param.h 34.In sys/conf.h 35.Ft void 36.Fn clone_handler "void *arg" "struct ucred *cr" "char *name" "int namelen" "struct cdev **dev" 37.Bd -literal 38EVENTHANDLER_REGISTER(dev_clone, clone_handler, arg, priority); 39.Ed 40.Ft void 41.Fn drain_dev_clone_events 42.Sh DESCRIPTION 43Device driver may register a listener that will be notified each time 44name lookup on the 45.Xr devfs 46mount point fails to find the vnode. 47Listener shall be registered for the 48.Va dev_clone 49event. 50When called, it is supplied with the first argument 51.Va arg 52that was specified at handler registration time, 53appropriate credentials 54.Va cr , 55.Va name 56of the length 57.Va namelen 58that was looked for. 59If handler decides that the name is appropriate and want to create device 60that will be associated with the name, it should return it to the devfs 61in the 62.Va dev . 63.Pp 64The 65.Fn drain_dev_clone_events 66function is a barrier. 67It is guaranteed that all calls to eventhandlers for dev_clone that were 68started before 69.Fn drain_dev_clone_events 70call, are finished before it returns control. 71.Pp 72.Sh SEE ALSO 73.Xr devfs 5 , 74.Xr namei 9 75