From: Ilya Dryomov <idryomov@gmail.com>
Date: Mon, 20 Sep 2021 19:52:57 +0000 (+0200)
Subject: rbd-mirror: unbreak one-way snapshot-based mirroring
X-Git-Tag: v16.2.7~18^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=4b8e1894545119c4d2498405119c2cd3f190d699;p=ceph.git

rbd-mirror: unbreak one-way snapshot-based mirroring

Snapshot replayer needs the remote's mirror peer uuid to find its
snapshots in the remote image.  It is obtained by listing remote's
mirror peers but RemotePoolPoller::handle_mirror_peer_list() skips
tx-only (MIRROR_PEER_DIRECTION_TX) peers.  In effect only rx-tx
(MIRROR_PEER_DIRECTION_RX_TX) peers are considered for matching
and snapshot replayer always fails with "failed to retrieve mirror
peer uuid from remote pool" error.

Instead, skip rx-only (MIRROR_PEER_DIRECTION_RX) peers as we are
definitely not interested in anything having to do with mirroring
_to_ the remote cluster.

Fixes: https://tracker.ceph.com/issues/52675
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit b02d3b0c5aa59aa294de43f94c793f5abf71ac03)
---

diff --git a/src/tools/rbd_mirror/RemotePoolPoller.cc b/src/tools/rbd_mirror/RemotePoolPoller.cc
index 4f5994f1da678..1ff2e41fc46d1 100644
--- a/src/tools/rbd_mirror/RemotePoolPoller.cc
+++ b/src/tools/rbd_mirror/RemotePoolPoller.cc
@@ -183,7 +183,7 @@ void RemotePoolPoller<I>::handle_mirror_peer_list(int r) {
 
   cls::rbd::MirrorPeer* matched_peer = nullptr;
   for (auto& peer : peers) {
-    if (peer.mirror_peer_direction == cls::rbd::MIRROR_PEER_DIRECTION_TX) {
+    if (peer.mirror_peer_direction == cls::rbd::MIRROR_PEER_DIRECTION_RX) {
       continue;
     }