From 4efd1a1b2f09a4b746dd9dc057986c6dadcb1317 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Fri, 25 Jul 2008 01:47:07 -0700 Subject: [PATCH] devcgroup: relax white-list protection down to RCU Currently this list is protected with a simple spinlock, even for reading from one. This is OK, but can be better. Actually I want it to be better very much, since after replacing the OpenVZ device permissions engine with the cgroup-based one I noticed, that we set 12 default device permissions for each newly created container (for /dev/null, full, terminals, ect devices), and people sometimes have up to 20 perms more, so traversing the ~30-40 elements list under a spinlock doesn't seem very good. Here's the RCU protection for white-list - dev_whitelist_item-s are added and removed under the devcg->lock, but are looked up in permissions checking under the rcu_read_lock. Signed-off-by: Pavel Emelyanov Acked-by: Serge Hallyn Cc: Balbir Singh Cc: Paul Menage Cc: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed