Commit 60bf8bf8 authored by Sage Weil's avatar Sage Weil
Browse files

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

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: default avatarSage Weil <>
parent 692d20f5
......@@ -123,6 +123,7 @@ struct ceph_msg_pos {
#define SOCK_CLOSED 11 /* socket state changed to closed */
#define OPENING 13 /* open connection w/ (possibly new) peer */
#define DEAD 14 /* dead, about to kfree */
#define BACKOFF 15
* A single connection with another host.
......@@ -1949,6 +1949,19 @@ static void con_work(struct work_struct *work);
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);
} else {
dout("con_work %p FAILED to back off %lu\n", con,
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)
else if (con->delay < MAX_DELAY_INTERVAL)
con->delay *= 2;
dout("fault queueing %p delay %lu\n", con, con->delay);
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 {
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);
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