librbd: update ref count when queueing AioCompletion

If the client releases the AioCompletion while librbd is waiting
to acquire the exclusive lock, the memory associated with the
completion will be freed too early.

Fixes: #11478
Backport: hammer
Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/librbd/ImageWatcher.cc b/src/librbd/ImageWatcher.cc
index 218f1a394e467c08e97a89cd273fd095d833d368..26499c65019eb18a18ce805693b65bbccd10971c 100644 (file)
--- a/src/librbd/ImageWatcher.cc
+++ b/src/librbd/ImageWatcher.cc
@@ -186,6 +186,8 @@ int ImageWatcher::request_lock(
     bool request_pending = !m_aio_requests.empty();
     ldout(m_image_ctx.cct, 15) << "queuing aio request: " << c
                               << dendl;
+
+    c->get();
     m_aio_requests.push_back(std::make_pair(restart_op, c));
     if (request_pending) {
       return 0;
@@ -532,6 +534,7 @@ void ImageWatcher::retry_aio_requests() {
     ldout(m_image_ctx.cct, 20) << "retrying aio request: " << iter->second
                               << dendl;
     iter->first(iter->second);
+    iter->second->put();
   }
 }