From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: [PATCH 1/1] ipc namespace: initialize init_ipc_ns.count to 1 Date: Wed, 4 Mar 2009 09:52:51 -0600 Message-ID: <20090304155251.GA11741@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: Linux Containers , lkml List-Id: containers.vger.kernel.org Hi Andrew, when I sent an earlier version of the posix mqueue namespaces patchset you called me on setting init_ipc_ns.count to 2. The following patch changes that to 1. This is safe because the 1-count is for swapper, who cannot unshare the namespace. Having init do unshare(CLONE_NEWIPC) only drops the count to 1. No pre-init resources other than tasks pin (and therefore can decrease the refcount on) an ipc_ns. Signed-off-by: Serge E. Hallyn --- ipc/msgutil.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/ipc/msgutil.c b/ipc/msgutil.c index e5d6da1..f095ee2 100644 --- a/ipc/msgutil.c +++ b/ipc/msgutil.c @@ -26,8 +26,7 @@ DEFINE_SPINLOCK(mq_lock); * and not CONFIG_IPC_NS. */ struct ipc_namespace init_ipc_ns = { - /* It's not for this patch to change, but should this be 1? */ - .count = ATOMIC_INIT(2), + .count = ATOMIC_INIT(1), #ifdef CONFIG_POSIX_MQUEUE .mq_queues_max = DFLT_QUEUESMAX, .mq_msg_max = DFLT_MSGMAX, -- 1.5.4.3