ocfs2: add uuid to ocfs2 thread name for problem analysis

A node can mount multiple ocfs2 volumes.  And if thread names are same for
each volume/domain, it will bring inconvenience when analyzing problems
because we have to identify which volume/domain the messages belong to.

Since thread name will be printed to messages, so add volume uuid or dlm
name to thread name can benefit problem analysis.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Gang He <ghe@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/dlm/dlmdomain.c

@@ -1866,6 +1866,7 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
 	int status;
 	unsigned int backoff;
 	unsigned int total_backoff = 0;
+	char wq_name[O2NM_MAX_NAME_LEN];
 
 	BUG_ON(!dlm);
 
@@ -1895,7 +1896,8 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
 		goto bail;
 	}
 
-	dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
+	snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name);
+	dlm->dlm_worker = create_singlethread_workqueue(wq_name);
 	if (!dlm->dlm_worker) {
 		status = -ENOMEM;
 		mlog_errno(status);