From: John Spray <john.spray@redhat.com>
Date: Tue, 3 Mar 2015 20:14:28 +0000 (+0000)
Subject: mds: flush immediately in do_open_truncate
X-Git-Tag: v9.0.0~218^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F3865%2Fhead;p=ceph.git

mds: flush immediately in do_open_truncate

Previously truncating opens were horribly laggy
for clients when the system was otherwise idle,
as they would wait for the next tick() before
proceeding.

Fixes: #11011
Signed-off-by: John Spray <john.spray@redhat.com>
---

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index d572340be1e7..846ade3cb0aa 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -3618,6 +3618,10 @@ void Server::do_open_truncate(MDRequestRef& mdr, int cmode)
 
   journal_and_reply(mdr, in, dn, le, new C_MDS_inode_update_finish(mds, mdr, in, old_size > 0,
 								   changed_ranges));
+  // Although the `open` part can give an early reply, the truncation won't
+  // happen until our EUpdate is persistent, to give the client a prompt
+  // response we must also flush that event.
+  mdlog->flush();
 }