tree bc3e2e4c4140f07ee1861b724ba7e1b295d7bbc6
parent a5001a0d9768568de5d613c3b3a5b9c7721299da
author Davidlohr Bueso <davidlohr.bueso@hp.com> 1373324476 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1373391207 -0700

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>