Bugzilla Bug 146284

Gentoo's sandbox triggers at random points a deadlock in FreeBSD 6.1-RELEASE
and 6-STABLE in devfs code resulting in the system being unable to touch the
filesystem. There is a patch as a result of my bug report to upstream fixing
this deadlock which will be applied to both -CURRENT and 6-STABLE.

If we want people to enable sandbox under FreeBSD we should be patching
freebsd-sources with this patch until 6.2 gets released. Note that the author
of the patch, Konstantin Belousov, says "this trades the deadlock for a race at
unmount time", which is however much better than the current state of things.

Dirty details:
http://www.freebsd.org/cgi/query-pr.cgi?pr=102335
http://marc.theaimsgroup.com/?l=freebsd-hackers&m=115592944408531&w=2
http://unleashed.amule.org/soc/2006/07/15/deadlock-driving-me-mad/
http://unleashed.amule.org/soc/2006/09/04/deadlock-dies/

Patch against 6.1-RELEASE to follow as attachment. In the FreeBSD link you can
find a patch against -CURRENT.

Created an attachment (id=95973) [edit]
Patch against 6.1-RELEASE fixing the deadlock (but racing at unmount time)

Added in 6.1-r4.