kern/40669: KMEMSTATS causes mount_ffs -o log to hang

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>Number:         40669
>Category:       kern
>Synopsis:       KMEMSTATS causes mount_ffs -o log to hang
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Feb 17 12:25:01 +0000 2009
>Originator:     Alan Barrett
>Release:        NetBSD 5.99.7
>Organization:
Not much
>Environment:
System: NetBSD 5.99.7 i386
>Description:
        "mount -t ffs -o log" hangs forever if the kernel has
        options KMEMSTATS.

>How-To-Repeat:
        I have a non-modular i386 kernel with options KMEMSTATS.

        I have a heavily customised /etc/rc which mounts the root file
        system, configures a cgd, and then attempts to mount a
        file system from the cgd using

                mount -t ffs -o log /dev/rcgd1a /cgd1a

        This mount hangs forever in wchan "wapbl".

        An almost-identical kernel without options KMEMSTATS works.

>Fix:
        Unknown.