From: Samuel Just <sjust@redhat.com>
Date: Wed, 15 Sep 2021 21:23:29 +0000 (+0000)
Subject: crimson/os/seastore/cache: Cache::get_root check for invalid
X-Git-Tag: v17.1.0~868^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F43178%2Fhead;p=ceph.git

crimson/os/seastore/cache: Cache::get_root check for invalid

As with Cache::get_extent, we need to check that the ref
is still valid after wait_io since it's not in the
read set yet.

Fixes: https://tracker.ceph.com/issues/52623
Signed-off-by: Samuel Just <sjust@redhat.com>
---

diff --git a/src/crimson/os/seastore/cache.cc b/src/crimson/os/seastore/cache.cc
index 500c327ee1746..f0a598f5f88bb 100644
--- a/src/crimson/os/seastore/cache.cc
+++ b/src/crimson/os/seastore/cache.cc
@@ -1171,12 +1171,18 @@ Cache::get_root_ret Cache::get_root(Transaction &t)
   } else {
     auto ret = root;
     DEBUGT("waiting root {}", t, *ret);
-    return ret->wait_io().then([FNAME, ret, &t] {
+    return ret->wait_io().then([this, FNAME, ret, &t] {
       DEBUGT("got root read {}", t, *ret);
-      t.root = ret;
-      t.add_to_read_set(ret);
-      return get_root_iertr::make_ready_future<RootBlockRef>(
-	ret);
+      if (!ret->is_valid()) {
+	DEBUGT("root became invalid: {}", t, *ret);
+	mark_transaction_conflicted(t, *ret);
+	return get_root_iertr::make_ready_future<RootBlockRef>();
+      } else {
+	t.root = ret;
+	t.add_to_read_set(ret);
+	return get_root_iertr::make_ready_future<RootBlockRef>(
+	  ret);
+      }
     });
   }
 }