5.4-STABLE panic in propagate_priority() and a tentative patch

[Dag-Erling Smørgrav]

Garry Belka <garry at NetworkPhysics.COM> writes:
> We saw several panics of the same kind on different systems running
> 5.4-STABLE. The panic was in propagate_priority() and was ultimately
> traced to vget() call in pfs_vncache_alloc(). vget() is called under
> global pfs mutex. When vget() sleeps, propagate_priority() in a
> different thread comes across a sleeping thread that owns a blocked
> mutex, and that causes a panic.

Could you please file a PR about this issue, with the patch attached?
(use 'send-pr -a /path/to/patch' to avoid clobbering whitespace)

DES
-- 
Dag-Erling Smørgrav - des at des.no