K 10
svn:author
V 3
mjg
K 8
svn:date
V 27
2020-10-29T12:56:02.466374Z
K 7
svn:log
V 458
vfs: add NDREINIT to facilitate repeated namei calls

struct nameidata mixes caller arguments, internal state and output, which
can be quite error prone.

Recent addition of valdiating ni_resflags uncovered a caller which could
repeatedly call namei, effectively operating on partially populated state.

Add bare minimium validation this does not happen. The real fix would
decouple aforementioned state.

Reported by:	pho
Tested by:	pho (different variant)

END