diff mbox

ocfs2: check if the ocfs2 lock resource be initialized before calling ocfs2_dlm_lock

Message ID 5518C165.10106@huawei.com
State New, archived
Headers show

Commit Message

Alex Chen March 30, 2015, 3:22 a.m. UTC
If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
the lock won't be dropped and then will lead umount hung. The case is
described below:

ocfs2_mknod
    ocfs2_mknod_locked
        __ocfs2_mknod_locked
            ocfs2_journal_access_di
            Failed because of -ENOMEM or other reasons, the inode lockres
            has not been initialized yet.

    iput(inode)
        ocfs2_evict_inode
            ocfs2_delete_inode
                ocfs2_inode_lock
                    ocfs2_inode_lock_full_nested
                        __ocfs2_cluster_lock
                        Succeeds and allocates a new dlm lockres.
            ocfs2_clear_inode
                ocfs2_open_unlock
                    ocfs2_drop_inode_locks
                        ocfs2_drop_lock
                        Since lockres has not been initialized, the lock
                        can't be dropped and the lockres can't be
                        migrated, thus umount will hang forever.

Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: joyce.xue <xuejiufei@huawei.com>

---
 fs/ocfs2/dlmglue.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Junxiao Bi April 16, 2015, 7:28 a.m. UTC | #1
Hi Alex,

On 03/30/2015 11:22 AM, alex chen wrote:
> If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
> the lock won't be dropped and then will lead umount hung. The case is
> described below:
> 
> ocfs2_mknod
>     ocfs2_mknod_locked
>         __ocfs2_mknod_locked
>             ocfs2_journal_access_di
>             Failed because of -ENOMEM or other reasons, the inode lockres
>             has not been initialized yet.

If failed here, is OCFS2_I(inode)->ip_inode_lockres initialized?  If not
how can you break __ocfs2_cluster_lock with the following condition?

if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))

Thanks,
Junxiao.

> 
>     iput(inode)
>         ocfs2_evict_inode
>             ocfs2_delete_inode
>                 ocfs2_inode_lock
>                     ocfs2_inode_lock_full_nested
>                         __ocfs2_cluster_lock
>                         Succeeds and allocates a new dlm lockres.
>             ocfs2_clear_inode
>                 ocfs2_open_unlock
>                     ocfs2_drop_inode_locks
>                         ocfs2_drop_lock
>                         Since lockres has not been initialized, the lock
>                         can't be dropped and the lockres can't be
>                         migrated, thus umount will hang forever.
> 
> Signed-off-by: Alex Chen <alex.chen@huawei.com>
> Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
> Reviewed-by: joyce.xue <xuejiufei@huawei.com>
> 
> ---
>  fs/ocfs2/dlmglue.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
> index 11849a4..8b23aa2 100644
> --- a/fs/ocfs2/dlmglue.c
> +++ b/fs/ocfs2/dlmglue.c
> @@ -1391,6 +1391,11 @@ static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
>  	int noqueue_attempted = 0;
>  	int dlm_locked = 0;
> 
> +	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
> +		mlog_errno(-EINVAL);
> +		return -EINVAL;
> +	}
> +
>  	ocfs2_init_mask_waiter(&mw);
> 
>  	if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
>
Alex Chen April 21, 2015, 2:54 a.m. UTC | #2
Hi Junxiao,

On 2015/4/16 15:28, Junxiao Bi wrote:
> Hi Alex,
> 
> On 03/30/2015 11:22 AM, alex chen wrote:
>> If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
>> the lock won't be dropped and then will lead umount hung. The case is
>> described below:
>>
>> ocfs2_mknod
>>     ocfs2_mknod_locked
>>         __ocfs2_mknod_locked
>>             ocfs2_journal_access_di
>>             Failed because of -ENOMEM or other reasons, the inode lockres
>>             has not been initialized yet.
> 
> If failed here, is OCFS2_I(inode)->ip_inode_lockres initialized?  If not

The OCFS2_I(inode)->ip_inode_lockres is initialized as follows:
__ocfs2_mknod_locked
    ocfs2_populate_inode
        ocfs2_inode_lock_res_init
            ocfs2_lock_res_init_common
So if ocfs2_journal_access_di is failed, the ip_inode_lockres will not be
initialized.
In this situation, we should not allocate a new dlm lockres through calling
ocfs2_dlm_lock() in __ocfs2_cluster_lock(), otherwise it will lead umount
hung. So we need bread __ocfs2_cluster_lock() if the inode lockres is not
be initialized, that is the condition
(!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) is TRUE.

> how can you break __ocfs2_cluster_lock with the following condition?
> 
> if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
> 
> Thanks,
> Junxiao.
> 
>>
>>     iput(inode)
>>         ocfs2_evict_inode
>>             ocfs2_delete_inode
>>                 ocfs2_inode_lock
>>                     ocfs2_inode_lock_full_nested
>>                         __ocfs2_cluster_lock
>>                         Succeeds and allocates a new dlm lockres.
>>             ocfs2_clear_inode
>>                 ocfs2_open_unlock
>>                     ocfs2_drop_inode_locks
>>                         ocfs2_drop_lock
>>                         Since lockres has not been initialized, the lock
>>                         can't be dropped and the lockres can't be
>>                         migrated, thus umount will hang forever.
>>
>> Signed-off-by: Alex Chen <alex.chen@huawei.com>
>> Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
>> Reviewed-by: joyce.xue <xuejiufei@huawei.com>
>>
>> ---
>>  fs/ocfs2/dlmglue.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
>> index 11849a4..8b23aa2 100644
>> --- a/fs/ocfs2/dlmglue.c
>> +++ b/fs/ocfs2/dlmglue.c
>> @@ -1391,6 +1391,11 @@ static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
>>  	int noqueue_attempted = 0;
>>  	int dlm_locked = 0;
>>
>> +	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
>> +		mlog_errno(-EINVAL);
>> +		return -EINVAL;
>> +	}
>> +
>>  	ocfs2_init_mask_waiter(&mw);
>>
>>  	if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
>>
> 
> 
> .
>
Junxiao Bi April 22, 2015, 1:46 a.m. UTC | #3
On 04/21/2015 10:54 AM, alex chen wrote:
> Hi Junxiao,
> 
> On 2015/4/16 15:28, Junxiao Bi wrote:
>> Hi Alex,
>>
>> On 03/30/2015 11:22 AM, alex chen wrote:
>>> If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
>>> the lock won't be dropped and then will lead umount hung. The case is
>>> described below:
>>>
>>> ocfs2_mknod
>>>     ocfs2_mknod_locked
>>>         __ocfs2_mknod_locked
>>>             ocfs2_journal_access_di
>>>             Failed because of -ENOMEM or other reasons, the inode lockres
>>>             has not been initialized yet.
>>
>> If failed here, is OCFS2_I(inode)->ip_inode_lockres initialized?  If not
> 
> The OCFS2_I(inode)->ip_inode_lockres is initialized as follows:
> __ocfs2_mknod_locked
>     ocfs2_populate_inode
>         ocfs2_inode_lock_res_init
>             ocfs2_lock_res_init_common
> So if ocfs2_journal_access_di is failed, the ip_inode_lockres will not be
> initialized.
> In this situation, we should not allocate a new dlm lockres through calling
> ocfs2_dlm_lock() in __ocfs2_cluster_lock(), otherwise it will lead umount
> hung. So we need bread __ocfs2_cluster_lock() if the inode lockres is not
> be initialized, that is the condition
> (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) is TRUE.

Looks good. Just didn't remind that inode_info is init once when it is
allocated from "ocfs2_inode_cache". lockres->l_flags is init there.

Thanks,
Junxiao.

> 
>> how can you break __ocfs2_cluster_lock with the following condition?
>>
>> if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
>>
>> Thanks,
>> Junxiao.
>>
>>>
>>>     iput(inode)
>>>         ocfs2_evict_inode
>>>             ocfs2_delete_inode
>>>                 ocfs2_inode_lock
>>>                     ocfs2_inode_lock_full_nested
>>>                         __ocfs2_cluster_lock
>>>                         Succeeds and allocates a new dlm lockres.
>>>             ocfs2_clear_inode
>>>                 ocfs2_open_unlock
>>>                     ocfs2_drop_inode_locks
>>>                         ocfs2_drop_lock
>>>                         Since lockres has not been initialized, the lock
>>>                         can't be dropped and the lockres can't be
>>>                         migrated, thus umount will hang forever.
>>>
>>> Signed-off-by: Alex Chen <alex.chen@huawei.com>
>>> Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
>>> Reviewed-by: joyce.xue <xuejiufei@huawei.com>
>>>
>>> ---
>>>  fs/ocfs2/dlmglue.c | 5 +++++
>>>  1 file changed, 5 insertions(+)
>>>
>>> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
>>> index 11849a4..8b23aa2 100644
>>> --- a/fs/ocfs2/dlmglue.c
>>> +++ b/fs/ocfs2/dlmglue.c
>>> @@ -1391,6 +1391,11 @@ static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
>>>  	int noqueue_attempted = 0;
>>>  	int dlm_locked = 0;
>>>
>>> +	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
>>> +		mlog_errno(-EINVAL);
>>> +		return -EINVAL;
>>> +	}
>>> +
>>>  	ocfs2_init_mask_waiter(&mw);
>>>
>>>  	if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
>>>
>>
>>
>> .
>>
>
Alex Chen April 22, 2015, 8:14 a.m. UTC | #4
On 2015/4/22 9:46, Junxiao Bi wrote:
> On 04/21/2015 10:54 AM, alex chen wrote:
>> Hi Junxiao,
>>
>> On 2015/4/16 15:28, Junxiao Bi wrote:
>>> Hi Alex,
>>>
>>> On 03/30/2015 11:22 AM, alex chen wrote:
>>>> If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
>>>> the lock won't be dropped and then will lead umount hung. The case is
>>>> described below:
>>>>
>>>> ocfs2_mknod
>>>>     ocfs2_mknod_locked
>>>>         __ocfs2_mknod_locked
>>>>             ocfs2_journal_access_di
>>>>             Failed because of -ENOMEM or other reasons, the inode lockres
>>>>             has not been initialized yet.
>>>
>>> If failed here, is OCFS2_I(inode)->ip_inode_lockres initialized?  If not
>>
>> The OCFS2_I(inode)->ip_inode_lockres is initialized as follows:
>> __ocfs2_mknod_locked
>>     ocfs2_populate_inode
>>         ocfs2_inode_lock_res_init
>>             ocfs2_lock_res_init_common
>> So if ocfs2_journal_access_di is failed, the ip_inode_lockres will not be
>> initialized.
>> In this situation, we should not allocate a new dlm lockres through calling
>> ocfs2_dlm_lock() in __ocfs2_cluster_lock(), otherwise it will lead umount
>> hung. So we need bread __ocfs2_cluster_lock() if the inode lockres is not
>> be initialized, that is the condition
>> (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) is TRUE.
> 
> Looks good. Just didn't remind that inode_info is init once when it is
> allocated from "ocfs2_inode_cache". lockres->l_flags is init there.
> 
> Thanks,
> Junxiao.
> 

Thank you for your remind. If the subject is "check if lockres->l_flags be
initialized to OCFS2_LOCK_INITIALIZED before calling ocfs2_dlm_lock" will
be better.

>>
>>> how can you break __ocfs2_cluster_lock with the following condition?
>>>
>>> if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
>>>
>>> Thanks,
>>> Junxiao.
>>>
>>>>
>>>>     iput(inode)
>>>>         ocfs2_evict_inode
>>>>             ocfs2_delete_inode
>>>>                 ocfs2_inode_lock
>>>>                     ocfs2_inode_lock_full_nested
>>>>                         __ocfs2_cluster_lock
>>>>                         Succeeds and allocates a new dlm lockres.
>>>>             ocfs2_clear_inode
>>>>                 ocfs2_open_unlock
>>>>                     ocfs2_drop_inode_locks
>>>>                         ocfs2_drop_lock
>>>>                         Since lockres has not been initialized, the lock
>>>>                         can't be dropped and the lockres can't be
>>>>                         migrated, thus umount will hang forever.
>>>>
>>>> Signed-off-by: Alex Chen <alex.chen@huawei.com>
>>>> Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
>>>> Reviewed-by: joyce.xue <xuejiufei@huawei.com>
>>>>
>>>> ---
>>>>  fs/ocfs2/dlmglue.c | 5 +++++
>>>>  1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
>>>> index 11849a4..8b23aa2 100644
>>>> --- a/fs/ocfs2/dlmglue.c
>>>> +++ b/fs/ocfs2/dlmglue.c
>>>> @@ -1391,6 +1391,11 @@ static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
>>>>  	int noqueue_attempted = 0;
>>>>  	int dlm_locked = 0;
>>>>
>>>> +	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
>>>> +		mlog_errno(-EINVAL);
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>>  	ocfs2_init_mask_waiter(&mw);
>>>>
>>>>  	if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
>>>>
>>>
>>>
>>> .
>>>
>>
> 
> 
> .
>
diff mbox

Patch

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 11849a4..8b23aa2 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -1391,6 +1391,11 @@  static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
 	int noqueue_attempted = 0;
 	int dlm_locked = 0;

+	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
+		mlog_errno(-EINVAL);
+		return -EINVAL;
+	}
+
 	ocfs2_init_mask_waiter(&mw);

 	if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)