From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junxiao Bi Date: Wed, 22 Apr 2015 09:46:51 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2: check if the ocfs2 lock resource be initialized before calling ocfs2_dlm_lock In-Reply-To: <5535BBC8.5030007@huawei.com> References: <5518C165.10106@huawei.com> <552F6487.4020707@oracle.com> <5535BBC8.5030007@huawei.com> Message-ID: <5536FD8B.9050903@oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com 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 >>> Reviewed-by: Joseph Qi >>> Reviewed-by: joyce.xue >>> >>> --- >>> 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) >>> >> >> >> . >> >