On Wednesday, September 26, 2012 8:48:03 am Ed Maste wrote: > On 26 September 2012 00:52, Konstantin Belousov <kostik...@gmail.com> wrote: > > On Tue, Sep 25, 2012 at 10:10:14PM +0000, Ed Maste wrote: > >> Author: emaste > >> Date: Tue Sep 25 22:10:14 2012 > >> New Revision: 240938 > >> URL: http://svn.freebsd.org/changeset/base/240938 > >> > >> Log: > >> Avoid INVARIANTS panic destroying an in-use tap(4) > >> > >> The requirement (implied by the KASSERT in tap_destroy) that the tap is > >> closed isn't valid; destroy_dev will block in devdrn while other threads > >> are in d_* functions. > > Are you sure ? > > > > The device may be opened, but no threads could be in any cdevsw > > methods. destroy_dev(9) only waits for threads to leave cdevsw methods, > > and not for the close to happen. > > My first approach mirrored if_tun, but jhb@ pointed out on IRC that > any open devices will revert to dead_devsw so that future accesses > will fail.
You do need to ensure that any resources in use by an open device are cleaned up, but I think devfs will do useful things such as destroy all the cdev_priv objects associated with a device after the "devdrn" sleep finishes, so that the cleanup generally happens "for free". -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
