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.c...@huawei.com>
>> Reviewed-by: Joseph Qi <joseph...@huawei.com>
>> Reviewed-by: joyce.xue <xuejiu...@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)
>>
>
>
> .
>
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