[106/151] lnet: ensure peer put back on dc request queue

Commit Message

James Simmons Sept. 30, 2019, 6:56 p.m. UTC

From: Bruno Faccini <[e-mail]>

Upon async PUT request received from peer already in discovery
process, lnet_peer_push_event() was not handling the case where
peer could be on working/ln_dc_working queue. This could lead
for peer not to be re-dsicovered as expected, but left on
working queue and to be finally timed-out.

Also ensure that peer will not be put back on request queue by
event handler if discovery is already completed.

WC-bug-id: https://jira.whamcloud.com/browse/LU-10123
Lustre-commit: d0185dd43394 ("LU-10123 lnet: ensure peer put back on dc request queue")
Signed-off-by: Bruno Faccini <[e-mail]>
Reviewed-on: https://review.whamcloud.com/30147
Reviewed-by: Amir Shehata <[e-mail]>
Reviewed-by: Dmitry Eremin <[e-mail]>
Reviewed-by: Olaf Weber <[e-mail]>
Reviewed-by: Doug Oucharek <[e-mail]>
Reviewed-by: Oleg Drokin <[e-mail]>
Signed-off-by: James Simmons <[e-mail]>
---
 net/lnet/lnet/peer.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

Patch

diff --git a/net/lnet/lnet/peer.c b/net/lnet/lnet/peer.c
index 52d4ec0..e2f8c28 100644
--- a/net/lnet/lnet/peer.c
+++ b/net/lnet/lnet/peer.c
@@ -1983,13 +1983,16 @@  void lnet_peer_push_event(struct lnet_event *ev)
 
 out:
 	/*
-	 * Queue the peer for discovery, and wake the discovery thread
-	 * if the peer was already queued, because its status changed.
+	 * Queue the peer for discovery if not done, force it on the request
+	 * queue and wake the discovery thread if the peer was already queued,
+	 * because its status changed.
 	 */
 	spin_unlock(&lp->lp_lock);
 	lnet_net_lock(LNET_LOCK_EX);
-	if (lnet_peer_queue_for_discovery(lp))
+	if (!lnet_peer_is_uptodate(lp) && lnet_peer_queue_for_discovery(lp)) {
+		list_move(&lp->lp_dc_list, &the_lnet.ln_dc_request);
 		wake_up(&the_lnet.ln_dc_waitq);
+	}
 	/* Drop refcount from lookup */
 	lnet_peer_decref_locked(lp);
 	lnet_net_unlock(LNET_LOCK_EX);
@@ -2348,7 +2351,11 @@  static void lnet_discovery_event_handler(struct lnet_event *event)
 		lnet_ping_buffer_decref(pbuf);
 		lnet_peer_decref_locked(lp);
 	}
-	if (rc == LNET_REDISCOVER_PEER) {
+
+	/* Put peer back at end of request queue, if discovery not already
+	 * done
+	 */
+	if (rc == LNET_REDISCOVER_PEER && !lnet_peer_is_uptodate(lp)) {
 		list_move_tail(&lp->lp_dc_list, &the_lnet.ln_dc_request);
 		wake_up(&the_lnet.ln_dc_waitq);
 	}