dlm: convert ls_recv_active from rw_semaphore to rwlock

Convert ls_recv_active rw_semaphore to an rwlock to avoid
sleeping, in preparation for softirq message processing.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/dlm_internal.h

@@ -653,7 +653,7 @@ struct dlm_ls {
 	uint64_t		ls_recover_seq;
 	struct dlm_recover	*ls_recover_args;
 	struct rw_semaphore	ls_in_recovery;	/* block local requests */
-	struct rw_semaphore	ls_recv_active;	/* block dlm_recv */
+	rwlock_t		ls_recv_active;	/* block dlm_recv */
 	struct list_head	ls_requestqueue;/* queue remote requests */
 	rwlock_t		ls_requestqueue_lock;
 	struct dlm_rcom		*ls_recover_buf;

fs/dlm/lock.c

@@ -4837,7 +4837,7 @@ void dlm_receive_buffer(const union dlm_packet *p, int nodeid)
 	/* this rwsem allows dlm_ls_stop() to wait for all dlm_recv threads to
 	   be inactive (in this ls) before transitioning to recovery mode */
 
-	down_read(&ls->ls_recv_active);
+	read_lock(&ls->ls_recv_active);
 	if (hd->h_cmd == DLM_MSG)
 		dlm_receive_message(ls, &p->message, nodeid);
 	else if (hd->h_cmd == DLM_RCOM)
@@ -4845,7 +4845,7 @@ void dlm_receive_buffer(const union dlm_packet *p, int nodeid)
 	else
 		log_error(ls, "invalid h_cmd %d from %d lockspace %x",
 			  hd->h_cmd, nodeid, le32_to_cpu(hd->u.h_lockspace));
-	up_read(&ls->ls_recv_active);
+	read_unlock(&ls->ls_recv_active);
 
 	dlm_put_lockspace(ls);
 }

fs/dlm/lockspace.c

@@ -552,7 +552,7 @@ static int new_lockspace(const char *name, const char *cluster,
 	ls->ls_recover_seq = get_random_u64();
 	ls->ls_recover_args = NULL;
 	init_rwsem(&ls->ls_in_recovery);
-	init_rwsem(&ls->ls_recv_active);
+	rwlock_init(&ls->ls_recv_active);
 	INIT_LIST_HEAD(&ls->ls_requestqueue);
 	rwlock_init(&ls->ls_requestqueue_lock);
 	spin_lock_init(&ls->ls_clear_proc_locks);

fs/dlm/member.c

@@ -630,7 +630,7 @@ int dlm_ls_stop(struct dlm_ls *ls)
 	 * message to the requestqueue without races.
 	 */
 
-	down_write(&ls->ls_recv_active);
+	write_lock(&ls->ls_recv_active);
 
 	/*
 	 * Abort any recovery that's in progress (see RECOVER_STOP,
@@ -654,7 +654,7 @@ int dlm_ls_stop(struct dlm_ls *ls)
 	 * requestqueue for later.
 	 */
 
-	up_write(&ls->ls_recv_active);
+	write_unlock(&ls->ls_recv_active);
 
 	/*
 	 * This in_recovery lock does two things:

fs/dlm/recoverd.c

@@ -103,7 +103,7 @@ static int enable_locking(struct dlm_ls *ls, uint64_t seq)
 {
 	int error = -EINTR;
 
-	down_write(&ls->ls_recv_active);
+	write_lock(&ls->ls_recv_active);
 
 	spin_lock(&ls->ls_recover_lock);
 	if (ls->ls_recover_seq == seq) {
@@ -115,7 +115,7 @@ static int enable_locking(struct dlm_ls *ls, uint64_t seq)
 	}
 	spin_unlock(&ls->ls_recover_lock);
 
-	up_write(&ls->ls_recv_active);
+	write_unlock(&ls->ls_recv_active);
 	return error;
 }