mds: eval stray on remove dentry replica

This happens because when handling an MCacheExpire,
we expire inodes first and then dentries, so when
the inodes are put() their dentries still are replicated
so eval_stray fails.  Do an explicit call to maybe_eval_stray
when handling the expire for the dentry in order to catch
this.

One hits this path when migrating a stray away from
a stopping MDS rank.

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

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 85e0634d113647cdf28723d2173dd7c78c4736f8..4898af301d6499cf3682432224cf08865c4c9a75 100644 (file)
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -7097,6 +7097,12 @@ void MDCache::dentry_remove_replica(CDentry *dn, mds_rank_t from, set<SimpleLock
   // fix lock
   if (dn->lock.remove_replica(from))
     gather_locks.insert(&dn->lock);
+
+  // Replicated strays might now be elegible for purge
+  CDentry::linkage_t *dnl = dn->get_linkage();
+  if (dnl->is_primary()) {
+    maybe_eval_stray(dnl->get_inode());
+  }
 }
 
 void MDCache::trim_client_leases()