From: Pavel Emelyanov Date: Tue, 29 Apr 2008 08:02:40 +0000 (-0700) Subject: sysctl: merge equal proc_sys_read and proc_sys_write X-Git-Tag: v2.6.26-rc1~447 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7708bfb1c855f2a076ef71cc21647deea022ebe7;p=pandora-kernel.git sysctl: merge equal proc_sys_read and proc_sys_write Many (most of) sysctls do not have a per-container sense. E.g. kernel.print_fatal_signals, vm.panic_on_oom, net.core.netdev_budget and so on and so forth. Besides, tuning then from inside a container is not even secure. On the other hand, hiding them completely from the container's tasks sometimes causes user-space to stop working. When developing net sysctl, the common practice was to duplicate a table and drop the write bits in table->mode, but this approach was not very elegant, lead to excessive memory consumption and was not suitable in general. Here's the alternative solution. To facilitate the per-container sysctls ctl_table_root-s were introduced. Each root contains a list of ctl_table_header-s that are visible to different namespaces. The idea of this set is to add the permissions() callback on the ctl_table_root to allow ctl root limit permissions to the same ctl_table-s. The main user of this functionality is the net-namespaces code, but later this will (should) be used by more and more namespaces, containers and control groups. Actually, this idea's core is in a single hunk in the third patch. First two patches are cleanups for sysctl code, while the third one mostly extends the arguments set of some sysctl functions. This patch: These ->read and ->write callbacks act in a very similar way, so merge these paths to reduce the number of places to patch later and shrink the .text size (a bit). Signed-off-by: Pavel Emelyanov Acked-by: "David S. Miller" Cc: "Eric W. Biederman" Cc: Alexey Dobriyan Cc: Denis V. Lunev Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed