commit ac0ba20ea6f2201a1589d6dc26ad1a4f0f967bb8
author Davidlohr Bueso <davidlohr.bueso@hp.com> Mon Jul 08 16:01:16 2013 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Tue Jul 09 10:33:27 2013 -0700
tree bc3e2e4c4140f07ee1861b724ba7e1b295d7bbc6
parent a5001a0d9768568de5d613c3b3a5b9c7721299da

ipc,msg: make msgctl_nolock lockless

While the INFO cmd doesn't take the ipc lock, the STAT commands do
acquire it unnecessarily.  We can do the permissions and security checks
only holding the rcu lock.

This function now mimics semctl_nolock().

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>