kern/43328: namei is harder than sys_extattrctl thinks

[pooka%iki.fi@localhost]

>Number:         43328
>Category:       kern
>Synopsis:       namei is harder than sys_extattrctl thinks
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed May 19 17:30:00 +0000 2010
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
>Description:
sys_extattrctl does namei() with a locked vnode.  That's not a good idea
for quite boomy reasons.

(didn't I file a PR about this or fix this already a few years ago?)
>How-To-Repeat:
extattrctl with a pathflip -> boom
>Fix:
namei in the opposite order?