commit e37a06f10994c2ba86f54d8f96734f2483a869b8
author Li Zefan <lizefan@huawei.com> Thu Apr 17 13:53:08 2014 +0800
committer Tejun Heo <tj@kernel.org> Thu Apr 17 11:18:06 2014 -0400
tree 6b53563f1b93588d1c40c52f0eecb049b20c5cff
parent c9eaa447e77efe77b7fa4c953bd62de8297fd6c5

cgroup: fix the retry path of cgroup_mount()

If we hit the retry path, we'll call parse_cgroupfs_options() again,
but the string we pass to it has been modified by the previous call
to this function.

This bug can be observed by:

  # mount -t cgroup -o name=foo,cpuset xxx /mnt && umount /mnt && \
    mount -t cgroup -o name=foo,cpuset xxx /mnt
  mount: wrong fs type, bad option, bad superblock on xxx,
         missing codepage or helper program, or other error
  ...

The second mount passed "name=foo,cpuset" to the parser, and then it
hit the retry path and call the parser again, but this time the string
passed to the parser is "name=foo".

To fix this, we avoid calling parse_cgroupfs_options() again in this
case.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>