X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=kernel%2Fcgroup.c;h=3737a682cdf52229ee78efa5c637164ba60dcc28;hb=f1a745710f001e8c2eec6d525396083e1f4c389a;hp=a7267bfd3765b930f5b544bbcaf8df23fab3cd06;hpb=3d2aa66ddaa3008ae2c71bca07eb5e8b08170c4a;p=~andy%2Flinux

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a7267bfd376..3737a682cdf 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -46,6 +46,7 @@
 #include <linux/cgroupstats.h>
 #include <linux/hash.h>
 #include <linux/namei.h>
+#include <linux/smp_lock.h>
 
 #include <asm/atomic.h>
 
@@ -842,6 +843,11 @@ static int parse_cgroupfs_options(char *data,
 				     struct cgroup_sb_opts *opts)
 {
 	char *token, *o = data ?: "all";
+	unsigned long mask = (unsigned long)-1;
+
+#ifdef CONFIG_CPUSETS
+	mask = ~(1UL << cpuset_subsys_id);
+#endif
 
 	opts->subsys_bits = 0;
 	opts->flags = 0;
@@ -886,6 +892,15 @@ static int parse_cgroupfs_options(char *data,
 		}
 	}
 
+	/*
+	 * Option noprefix was introduced just for backward compatibility
+	 * with the old cpuset, so we allow noprefix only if mounting just
+	 * the cpuset subsystem.
+	 */
+	if (test_bit(ROOT_NOPREFIX, &opts->flags) &&
+	    (opts->subsys_bits & mask))
+		return -EINVAL;
+
 	/* We can't have an empty hierarchy */
 	if (!opts->subsys_bits)
 		return -EINVAL;
@@ -900,6 +915,7 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
 	struct cgroup *cgrp = &root->top_cgroup;
 	struct cgroup_sb_opts opts;
 
+	lock_kernel();
 	mutex_lock(&cgrp->dentry->d_inode->i_mutex);
 	mutex_lock(&cgroup_mutex);
 
@@ -927,6 +943,7 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
 	kfree(opts.release_agent);
 	mutex_unlock(&cgroup_mutex);
 	mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
+	unlock_kernel();
 	return ret;
 }