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authorJunxiao Bi <junxiao.bi@oracle.com>2014-08-29 15:19:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-29 16:28:16 -0700
commitc43c363def04cdaed0d9e26dae846081f55714e7 (patch)
tree81b981068d68bb415cfaa0f8fb9293b2e41fc6ea
parent2b462638e41ea62230297c21c4da9955937b7a3c (diff)
downloadlinux-stericsson-c43c363def04cdaed0d9e26dae846081f55714e7.tar.gz
ocfs2: o2net: don't shutdown connection when idle timeout
This patch series is to fix a possible message lost bug in ocfs2 when network go bad. This bug will cause ocfs2 hung forever even network become good again. The messages may lost in this case. After the tcp connection is established between two nodes, an idle timer will be set to check its state periodically, if no messages are received during this time, idle timer will timeout, it will shutdown the connection and try to reconnect, so pending messages in tcp queues will be lost. This messages may be from dlm. Dlm may get hung in this case. This may cause the whole ocfs2 cluster hung. This is very possible to happen when network state goes bad. Do the reconnect is useless, it will fail if network state is still bad. Just waiting there for network recovering may be a good idea, it will not lost messages and some node will be fenced until cluster goes into split-brain state, for this case, Tcp user timeout is used to override the tcp retransmit timeout. It will timeout after 25 days, user should have notice this through the provided log and fix the network, if they don't, ocfs2 will fall back to original reconnect way. This patch (of 3): Some messages in the tcp queue maybe lost if we shutdown the connection and reconnect when idle timeout. If packets lost and reconnect success, then the ocfs2 cluster maybe hung. To fix this, we can leave the connection there and do the fence decision when idle timeout, if network recover before fence dicision is made, the connection survive without lost any messages. This bug can be saw when network state go bad. It may cause ocfs2 hung forever if some packets lost. With this fix, ocfs2 will recover from hung if network becomes good again. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ocfs2/cluster/tcp.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index 681691bc233a..2334bfc966c1 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -1536,16 +1536,20 @@ static void o2net_idle_timer(unsigned long data)
#endif
printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
- "idle for %lu.%lu secs, shutting it down.\n", SC_NODEF_ARGS(sc),
- msecs / 1000, msecs % 1000);
+ "idle for %lu.%lu secs.\n",
+ SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000);
- /*
- * Initialize the nn_timeout so that the next connection attempt
- * will continue in o2net_start_connect.
+ /* idle timerout happen, don't shutdown the connection, but
+ * make fence decision. Maybe the connection can recover before
+ * the decision is made.
*/
atomic_set(&nn->nn_timeout, 1);
+ o2quo_conn_err(o2net_num_from_nn(nn));
+ queue_delayed_work(o2net_wq, &nn->nn_still_up,
+ msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
+
+ o2net_sc_reset_idle_timer(sc);
- o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
}
static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
@@ -1560,6 +1564,15 @@ static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
{
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+
+ /* clear fence decision since the connection recover from timeout*/
+ if (atomic_read(&nn->nn_timeout)) {
+ o2quo_conn_up(o2net_num_from_nn(nn));
+ cancel_delayed_work(&nn->nn_still_up);
+ atomic_set(&nn->nn_timeout, 0);
+ }
+
/* Only push out an existing timer */
if (timer_pending(&sc->sc_idle_timeout))
o2net_sc_reset_idle_timer(sc);