From 70eb9c751b5165f2b9e094828dde0e66de7cefaa Mon Sep 17 00:00:00 2001
From: Jason Dillaman <dillaman@redhat.com>
Date: Wed, 26 Aug 2020 19:40:39 -0400
Subject: [PATCH] librbd: flush all incomplete in-flight IOs upon image close

Fixes: https://tracker.ceph.com/issues/46875
Signed-off-by: Jason Dillaman <dillaman@redhat.com>
---
 src/librbd/image/CloseRequest.cc    | 57 +++++++++++++++--------------
 src/librbd/image/CloseRequest.h     | 23 ++++++------
 src/librbd/io/QueueImageDispatch.cc |  4 --
 3 files changed, 41 insertions(+), 43 deletions(-)

diff --git a/src/librbd/image/CloseRequest.cc b/src/librbd/image/CloseRequest.cc
index a5543ff38bd..c12cecd52d7 100644
--- a/src/librbd/image/CloseRequest.cc
+++ b/src/librbd/image/CloseRequest.cc
@@ -90,6 +90,34 @@ void CloseRequest<I>::handle_shut_down_update_watchers(int r) {
                << dendl;
   }
 
+  send_flush();
+}
+
+template <typename I>
+void CloseRequest<I>::send_flush() {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 10) << this << " " << __func__ << dendl;
+
+  std::shared_lock owner_locker{m_image_ctx->owner_lock};
+  auto ctx = create_context_callback<
+    CloseRequest<I>, &CloseRequest<I>::handle_flush>(this);
+  auto aio_comp = io::AioCompletion::create_and_start(ctx, m_image_ctx,
+                                                      io::AIO_TYPE_FLUSH);
+  auto req = io::ImageDispatchSpec<I>::create_flush(
+    *m_image_ctx, io::IMAGE_DISPATCH_LAYER_API_START, aio_comp,
+    io::FLUSH_SOURCE_INTERNAL, {});
+  req->send();
+}
+
+template <typename I>
+void CloseRequest<I>::handle_flush(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 10) << this << " " << __func__ << ": r=" << r << dendl;
+
+  if (r < 0) {
+    lderr(cct) << "failed to flush IO: " << cpp_strerror(r) << dendl;
+  }
+
   send_shut_down_exclusive_lock();
 }
 
@@ -108,7 +136,7 @@ void CloseRequest<I>::send_shut_down_exclusive_lock() {
   }
 
   if (m_exclusive_lock == nullptr) {
-    send_flush();
+    send_unregister_image_watcher();
     return;
   }
 
@@ -148,33 +176,6 @@ void CloseRequest<I>::handle_shut_down_exclusive_lock(int r) {
   send_unregister_image_watcher();
 }
 
-template <typename I>
-void CloseRequest<I>::send_flush() {
-  CephContext *cct = m_image_ctx->cct;
-  ldout(cct, 10) << this << " " << __func__ << dendl;
-
-  std::shared_lock owner_locker{m_image_ctx->owner_lock};
-  auto ctx = create_context_callback<
-    CloseRequest<I>, &CloseRequest<I>::handle_flush>(this);
-  auto aio_comp = io::AioCompletion::create_and_start(ctx, m_image_ctx,
-                                                      io::AIO_TYPE_FLUSH);
-  auto req = io::ImageDispatchSpec<I>::create_flush(
-    *m_image_ctx, io::IMAGE_DISPATCH_LAYER_INTERNAL_START, aio_comp,
-    io::FLUSH_SOURCE_INTERNAL, {});
-  req->send();
-}
-
-template <typename I>
-void CloseRequest<I>::handle_flush(int r) {
-  CephContext *cct = m_image_ctx->cct;
-  ldout(cct, 10) << this << " " << __func__ << ": r=" << r << dendl;
-
-  if (r < 0) {
-    lderr(cct) << "failed to flush IO: " << cpp_strerror(r) << dendl;
-  }
-  send_unregister_image_watcher();
-}
-
 template <typename I>
 void CloseRequest<I>::send_unregister_image_watcher() {
   if (m_image_ctx->image_watcher == nullptr) {
diff --git a/src/librbd/image/CloseRequest.h b/src/librbd/image/CloseRequest.h
index 7f9f0d52ea6..ee298aa9d07 100644
--- a/src/librbd/image/CloseRequest.h
+++ b/src/librbd/image/CloseRequest.h
@@ -33,14 +33,15 @@ private:
    * BLOCK_IMAGE_WATCHER (skip if R/O)
    *    |
    *    v
-   * SHUT_DOWN_UPDATE_WATCHERS  . .
-   *    |                         . (exclusive lock disabled)
-   *    v                         v
-   * SHUT_DOWN_EXCLUSIVE_LOCK   FLUSH
-   *    |                         .
-   *    |     . . . . . . . . . . .
-   *    |     .
-   *    v     v
+   * SHUT_DOWN_UPDATE_WATCHERS
+   *    |
+   *    v
+   * FLUSH
+   *    |
+   *    v (skip if disabled)
+   * SHUT_DOWN_EXCLUSIVE_LOCK
+   *    |
+   *    v
    * UNREGISTER_IMAGE_WATCHER (skip if R/O)
    *    |
    *    v
@@ -82,12 +83,12 @@ private:
   void send_shut_down_update_watchers();
   void handle_shut_down_update_watchers(int r);
 
-  void send_shut_down_exclusive_lock();
-  void handle_shut_down_exclusive_lock(int r);
-
   void send_flush();
   void handle_flush(int r);
 
+  void send_shut_down_exclusive_lock();
+  void handle_shut_down_exclusive_lock(int r);
+
   void send_unregister_image_watcher();
   void handle_unregister_image_watcher(int r);
 
diff --git a/src/librbd/io/QueueImageDispatch.cc b/src/librbd/io/QueueImageDispatch.cc
index 607d35df3f7..a07557aa278 100644
--- a/src/librbd/io/QueueImageDispatch.cc
+++ b/src/librbd/io/QueueImageDispatch.cc
@@ -107,10 +107,6 @@ bool QueueImageDispatch<I>::flush(
   auto cct = m_image_ctx->cct;
   ldout(cct, 20) << "tid=" << tid << dendl;
 
-  if (flush_source != FLUSH_SOURCE_USER) {
-    return false;
-  }
-
   *dispatch_result = DISPATCH_RESULT_CONTINUE;
   m_flush_tracker->flush(on_dispatched);
   return true;
-- 
2.39.5