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authorSage Weil <sage@newdream.net>2011-03-04 12:24:28 -0800
committerSage Weil <sage@newdream.net>2011-03-04 12:24:28 -0800
commit60bf8bf8815e6adea4c1d0423578c3b8000e2ec8 (patch)
treece7140c32a3f177816f4029a88eb99e15bda6943 /net
parent692d20f576fb26f62c83f80dbf3ea899998391b7 (diff)
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libceph: fix msgr backoff
With commit f363e45f we replaced a bunch of hacky workqueue mutual exclusion logic with the WQ_NON_REENTRANT flag. One pieces of fallout is that the exponential backoff breaks in certain cases: * con_work attempts to connect. * we get an immediate failure, and the socket state change handler queues immediate work. * con_work calls con_fault, we decide to back off, but can't queue delayed work. In this case, we add a BACKOFF bit to make con_work reschedule delayed work next time it runs (which should be immediately). Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'net')
-rw-r--r--net/ceph/messenger.c30
1 files changed, 28 insertions, 2 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 6bd5025f6220..46fbc422ba74 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1949,6 +1949,19 @@ static void con_work(struct work_struct *work)
work.work);
mutex_lock(&con->mutex);
+ if (test_and_clear_bit(BACKOFF, &con->state)) {
+ dout("con_work %p backing off\n", con);
+ if (queue_delayed_work(ceph_msgr_wq, &con->work,
+ round_jiffies_relative(con->delay))) {
+ dout("con_work %p backoff %lu\n", con, con->delay);
+ mutex_unlock(&con->mutex);
+ return;
+ } else {
+ con->ops->put(con);
+ dout("con_work %p FAILED to back off %lu\n", con,
+ con->delay);
+ }
+ }
if (test_bit(CLOSED, &con->state)) { /* e.g. if we are replaced */
dout("con_work CLOSED\n");
@@ -2017,11 +2030,24 @@ static void ceph_fault(struct ceph_connection *con)
con->delay = BASE_DELAY_INTERVAL;
else if (con->delay < MAX_DELAY_INTERVAL)
con->delay *= 2;
- dout("fault queueing %p delay %lu\n", con, con->delay);
con->ops->get(con);
if (queue_delayed_work(ceph_msgr_wq, &con->work,
- round_jiffies_relative(con->delay)) == 0)
+ round_jiffies_relative(con->delay))) {
+ dout("fault queued %p delay %lu\n", con, con->delay);
+ } else {
con->ops->put(con);
+ dout("fault failed to queue %p delay %lu, backoff\n",
+ con, con->delay);
+ /*
+ * In many cases we see a socket state change
+ * while con_work is running and end up
+ * queuing (non-delayed) work, such that we
+ * can't backoff with a delay. Set a flag so
+ * that when con_work restarts we schedule the
+ * delay then.
+ */
+ set_bit(BACKOFF, &con->state);
+ }
}
out_unlock: