client: fix choose_target_mds for requests that do name lookup

There are two cases that a dirfrag is not recorded in CInode::fragmap.
One is that the dirfrag is not subtree root, another is that client does
not know which mds is dirfrag's auth mds. For the both cases, requests
that do name lookup are better to sent to dir inode's auth mds.

Fixes: http://tracker.ceph.com/issues/26860
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
(cherry picked from commit 436d1741e623748bc0dfd4e305d4c07cc602a093)

Conflicts:
	src/client/Client.cc : Resolved in choose_target_mds

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 7043f9058a405acc430f77774054f75da93cafb9..12bb20e00d97db789ebe9e117c74662d7396f01a 100644 (file)
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -1465,6 +1465,10 @@ mds_rank_t Client::choose_target_mds(MetaRequest *req, Inode** phash_diri)
        mds = in->fragmap[fg];
        if (phash_diri)
          *phash_diri = in;
+      } else if (in->auth_cap) {
+       mds = in->auth_cap->session->mds_num;
+      }
+      if (mds >= 0) {
        ldout(cct, 10) << "choose_target_mds from dirfragtree hash" << dendl;
        goto out;
       }