Reproducible panic of 6.2 on double mount ntfs

[Jan Henrik Sylvester]

Jan Henrik Sylvester wrote:
> With '/dev/ad0s1 /mnt/ad0s1 ntfs ro,noauto 0 0' in fstab, if I issue 
> 'mount /mnt/ad0s1' twice, I always get a panic with the message:
> 
> panic: lockmgr: locking against myself

I should have done some more intelligent research before...

kern/89966 (6.0-STABLE) is exactly what I see. (The difference between 
my mount+fstab and manual mount_ntfs is that the first includes ro.)

kern/104393 (7.0-CURRENT) does not even have the ro, but is otherwise 
the same.

kern/71391 (5.2.1-RELEASE) might be related...

I wonder why a panic that seems to be so easy to reproduce is not 
analyzed and fixed -- probably ntfs is simply not very important to 
anyone and the panic can be avoided quite easily.

Since I should be able to avoid issuing repeated execution of mount with 
some concentration (I ran into this four times now), it should not be 
too much of an issue for me, either...

Regards,
Jan Henrik