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authorTejun Heo <tj@kernel.org>2013-06-14 11:18:22 -0700
committerTejun Heo <tj@kernel.org>2013-06-18 08:14:23 -0700
commit6db8e85c5c1f89cd0183b76dab027c81009f129f (patch)
tree6195edbc8abb6645d39a4986fd2d48c89bbefa92 /kernel
parentf63674fd0d6afa1ba24309aee1f8c60195d39041 (diff)
downloadop-kernel-dev-6db8e85c5c1f89cd0183b76dab027c81009f129f.zip
op-kernel-dev-6db8e85c5c1f89cd0183b76dab027c81009f129f.tar.gz
cgroup: disallow rename(2) if sane_behavior
cgroup's rename(2) isn't a proper migration implementation - it can't move the cgroup to a different parent in the hierarchy. All it can do is swapping the name string for that cgroup. This isn't useful and can mislead users to think that cgroup supports proper cgroup-level migration. Disallow rename(2) if sane_behavior. v2: Fail with -EPERM instead of -EINVAL so that it matches the vfs return value when ->rename is not implemented as suggested by Li. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2e9da7b..c2c64005 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2508,6 +2508,13 @@ static int cgroup_rename(struct inode *old_dir, struct dentry *old_dentry,
cgrp = __d_cgrp(old_dentry);
+ /*
+ * This isn't a proper migration and its usefulness is very
+ * limited. Disallow if sane_behavior.
+ */
+ if (cgroup_sane_behavior(cgrp))
+ return -EPERM;
+
name = cgroup_alloc_name(new_dentry);
if (!name)
return -ENOMEM;
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