[lustre-devel] [PATCH 14/22] lnet: Force full discovery cycle
James Simmons
jsimmons at infradead.org
Tue Jun 2 17:59:53 PDT 2020
From: Amir Shehata <ashehata at whamcloud.com>
There are scenarios where there could be a discrepancy between
cached peer information and reality. In these cases what could
end-up happening is incomplete interface information might be
cached because one side determined that the peer didn't require
a PUSH. This will lead to undesired MR behavior, where not all
the interfaces are used for a period of time.
Therefore, it is safer to always force a full discovery cycle:
GET/PUSH to ensure both sides are up-to-date.
In the NMR case, when discovery is turned off, make sure to flag
discovery as complete to avoid stalling the state machine.
WC-bug-id: https://jira.whamcloud.com/browse/LU-13477
Lustre-commit: 9bafd530d7858 ("LU-13477 lnet: Force full discovery cycle")
Signed-off-by: Amir Shehata <ashehata at whamcloud.com>
Reviewed-on: https://review.whamcloud.com/38322
Reviewed-by: Chris Horn <chris.horn at hpe.com>
Reviewed-by: Serguei Smirnov <ssmirnov at whamcloud.com>
Reviewed-by: Oleg Drokin <green at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
net/lnet/lnet/peer.c | 40 ++++++++++++++++++++++++----------------
net/lnet/lnet/router.c | 5 +++--
2 files changed, 27 insertions(+), 18 deletions(-)
diff --git a/net/lnet/lnet/peer.c b/net/lnet/lnet/peer.c
index 60749da..5869a20 100644
--- a/net/lnet/lnet/peer.c
+++ b/net/lnet/lnet/peer.c
@@ -1179,6 +1179,11 @@ struct lnet_peer_ni *
lp = lpni->lpni_peer_net->lpn_peer;
while (!lnet_peer_is_uptodate(lp)) {
+ spin_lock(&lp->lp_lock);
+ /* force a full discovery cycle */
+ lp->lp_state |= LNET_PEER_FORCE_PING | LNET_PEER_FORCE_PUSH;
+ spin_unlock(&lp->lp_lock);
+
rc = lnet_discover_peer_locked(lpni, cpt, true);
if (rc)
goto out_decref;
@@ -3043,6 +3048,19 @@ static int lnet_peer_push_failed(struct lnet_peer *lp)
return rc ? rc : LNET_REDISCOVER_PEER;
}
+/* Mark the peer as discovered. */
+static int lnet_peer_discovered(struct lnet_peer *lp)
+__must_hold(&lp->lp_lock)
+{
+ lp->lp_state |= LNET_PEER_DISCOVERED;
+ lp->lp_state &= ~(LNET_PEER_DISCOVERING |
+ LNET_PEER_REDISCOVER);
+
+ CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
+
+ return 0;
+}
+
/* Active side of push. */
static int lnet_peer_send_push(struct lnet_peer *lp)
__must_hold(&lp->lp_lock)
@@ -3056,6 +3074,12 @@ static int lnet_peer_send_push(struct lnet_peer *lp)
/* Don't push to a non-multi-rail peer. */
if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
lp->lp_state &= ~LNET_PEER_FORCE_PUSH;
+ /* if peer's NIDs are uptodate then peer is discovered */
+ if (lp->lp_state & LNET_PEER_NIDS_UPTODATE) {
+ rc = lnet_peer_discovered(lp);
+ return rc;
+ }
+
return 0;
}
@@ -3147,22 +3171,6 @@ static void lnet_peer_discovery_error(struct lnet_peer *lp, int error)
}
/*
- * Mark the peer as discovered.
- */
-static int lnet_peer_discovered(struct lnet_peer *lp)
-__must_hold(&lp->lp_lock)
-{
- lp->lp_state |= LNET_PEER_DISCOVERED;
- lp->lp_state &= ~(LNET_PEER_DISCOVERING |
- LNET_PEER_REDISCOVER);
-
- CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
-
- return 0;
-}
-
-
-/*
* Discovering this peer is taking too long. Cancel any Ping or Push
* that discovery is waiting on by unlinking the relevant MDs. The
* lnet_discovery_event_handler() will proceed from here and complete
diff --git a/net/lnet/lnet/router.c b/net/lnet/lnet/router.c
index af50e51..903d027 100644
--- a/net/lnet/lnet/router.c
+++ b/net/lnet/lnet/router.c
@@ -1154,9 +1154,10 @@ bool lnet_router_checker_active(void)
spin_unlock(&rtr->lp_lock);
continue;
}
- /* make sure we actively discover the router */
+ /* make sure we fully discover the router */
rtr->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
- rtr->lp_state |= LNET_PEER_RTR_DISCOVERY;
+ rtr->lp_state |= LNET_PEER_FORCE_PING | LNET_PEER_FORCE_PUSH |
+ LNET_PEER_RTR_DISCOVERY;
spin_unlock(&rtr->lp_lock);
/* find the peer_ni associated with the primary NID */
--
1.8.3.1
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