From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junxiao Bi <junxiao.bi@oracle.com>
Date: Thu, 16 Apr 2015 15:28:07 +0800
Subject: [Ocfs2-devel] [PATCH] ocfs2: check if the ocfs2 lock resource
 be initialized before calling ocfs2_dlm_lock
In-Reply-To: <5518C165.10106@huawei.com>
References: <5518C165.10106@huawei.com>
Message-ID: <552F6487.4020707@oracle.com>
List-Id: <ocfs2-devel.oss.oracle.com>
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To: ocfs2-devel@oss.oracle.com

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)
>