[patch 03/15] cgroup: dont call vfs_mkdir

[Miklos Szeredi <miklos@szeredi.hu>]

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From: Miklos Szeredi <mszeredi@suse.cz>

cgroup_clone() calls vfs_mkdir() to create a directory in the cgroup
filesystem.  Replace with explicit call to cgroup_mkdir() and
fsnotify_mkdir().

This is equivalent, except that the following functions are not called
before cgroup_mkdir():

 - may_create()
 - security_inode_mkdir()
 - DQUOT_INIT()

Permission to clone the cgroup has already been checked in
copy_namespaces() (requiring CAP_SYS_ADMIN).  Additional file system
related capability checks are inappropriate and confusing.

The quota check is unnecessary, as quotas don't make any sense for
this filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Paul Menage <menage@google.com>
---
 kernel/cgroup.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6/kernel/cgroup.c
===================================================================
--- linux-2.6.orig/kernel/cgroup.c	2008-05-05 11:29:21.000000000 +0200
+++ linux-2.6/kernel/cgroup.c	2008-05-05 11:29:25.000000000 +0200
@@ -25,6 +25,7 @@
 #include <linux/cgroup.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
+#include <linux/fsnotify.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/mm.h>
@@ -2928,7 +2929,9 @@ int cgroup_clone(struct task_struct *tsk
 	}
 
 	/* Create the cgroup directory, which also creates the cgroup */
-	ret = vfs_mkdir(inode, dentry, S_IFDIR | 0755);
+	ret = cgroup_mkdir(inode, dentry, S_IFDIR);
+	if (!ret)
+		fsnotify_mkdir(inode, dentry);
 	child = __d_cgrp(dentry);
 	dput(dentry);
 	if (ret) {

--