[Bug 275870] [unionfs] [zfs] kernel panic on umount

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=275870

--- Comment #2 from Jason A. Harmening <jah@FreeBSD.org> ---
It looks like this was caused by the vfs_unregister_upper() calls I added in
14.  I'm a bit surprised that zfs rollback obliterates the v_mount field of the
upper/lower vnodes, but then I'm not familiar with that code.  In any case,
unionfs should probably cache the ref'ed upper/lower mount objects returned by
vfs_register_upper_from_vp (as nullfs already does), because there are several
cases outside of unmount() in which unionfs directly accesses
ump->um_[lower|upper]vp->v_mount which aren't likely to be safe in the presence
of a concurrent (recursive) forced unmount.

-- 
You are receiving this mail because:
You are the assignee for the bug.