kern/145750: unionfs locks the machine

Harald Schmalzbauer freebsd at
Fri Apr 16 07:20:01 UTC 2010

>Number:         145750
>Category:       kern
>Synopsis:       unionfs locks the machine
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Apr 16 07:20:00 UTC 2010
>Originator:     Harald Schmalzbauer
>Release:        FreeBSD 8.0-RELEASE-p2 amd64
System: FreeBSD 8.0-RELEASE-p2 FreeBSD 8.0-RELEASE-p2 #2: Fri Feb 5 15:06:19 CET 2010 admin at amd64

	There are several LORs with unionfs reported. One seems to lead to a hard lock.
For example I used to mount /usr/local/etc via unionfs over read-only unerlaying ufs.
There are reproducably hanging processes with status D+ ofter a short time.
This used to work with FreeBSD-7, but also causes problems on -current (see kern/141950)
	mount_unionfs /somedir/anotherdir /usr/local/etc and try starting lighttpd
with php-fastcgi for example.
mount_unionfs /somedir /root while / is readonly. Su will hang and force yout to hard reset the machine.



More information about the freebsd-bugs mailing list