Re: [PATCH] cgroup: fix reverse unlock sequence in cgroup_get_sb

[Balbir Singh <balbir@linux.vnet.ibm.com>]

* Xiaotian Feng <dfeng@redhat.com> [2009-07-21 18:25:26]:

> In cgroup_get_sb, the lock sequence is:
> 	mutex_lock(&inode->i_mutex);
> 	mutex_lock(&cgroup->mutex);
> so the last unlock sequence should be:
> 	mutex_unlock(&cgroup->mutex);
> 	mutex_unlock(&inode->i_mutex);
> 
> Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
> ---
>  kernel/cgroup.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index 3737a68..11ef162 100644
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -1140,8 +1140,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
>  		BUG_ON(root->number_of_cgroups != 1);
> 
>  		cgroup_populate_dir(root_cgrp);
> -		mutex_unlock(&inode->i_mutex);
>  		mutex_unlock(&cgroup_mutex);
> +		mutex_unlock(&inode->i_mutex);
>  	}
>

Seems reasonable to me. You might also want to mention that elsewhere
the sequence is unlock cgroup_mutex followed by inode->i_mutex.

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
 
 
-- 
	Balbir