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

[Danny Feng <dfeng@redhat.com>]

On 07/21/2009 07:10 PM, Balbir Singh wrote:
> * 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.
Yep, thank you very much:-)
>
> Acked-by: Balbir Singh<balbir@linux.vnet.ibm.com>
>
>