mds: do not try fragmenting or exporting a quiesced directory

And handle inode becoming quiesced after op is created.

Fixes: https://tracker.ceph.com/issues/65603
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

src/mds/MDCache.cc

@@ -11685,6 +11685,10 @@ bool MDCache::can_fragment(CInode *diri, const std::vector<CDir*>& dirs)
     dout(7) << "can_fragment: i won't fragment mdsdir or .ceph" << dendl;
     return false;
   }
+  if (diri->is_quiesced()) {
+    dout(7) << "can_fragment: directory inode is quiesced" << dendl;
+    return false;
+  }
 
   for (const auto& dir : dirs) {
     if (dir->scrub_is_in_progress()) {
@@ -12093,13 +12097,18 @@ void MDCache::dispatch_fragment_dir(const MDRequestRef& mdr)
     lov.lock_scatter_gather(&diri->nestlock);
     lov.lock_scatter_gather(&diri->filelock);
     if (!mds->locker->acquire_locks(mdr, lov, NULL, {}, true)) {
+      /* if quiescelock cannot be wrlocked, we cannot block with tree frozen */
+      if (!mdr->is_wrlocked(&diri->quiescelock)) {
+        mdr->aborted = true;
+      }
       if (!mdr->aborted)
 	return;
     }
   }
 
   if (mdr->aborted) {
-    dout(10) << " can't auth_pin " << *diri << ", requeuing dir "
+    dout(10) << " can't auth_pin or acquire quiescelock on "
+             << *diri << ", requeuing dir "
 	     << info.dirs.front()->dirfrag() << dendl;
     if (info.bits > 0)
       mds->balancer->queue_split(info.dirs.front(), false);

src/mds/Migrator.cc

@@ -804,6 +804,9 @@ void Migrator::export_dir(CDir *dir, mds_rank_t dest)
              && parent->get_parent_dir()->ino() != MDS_INO_MDSDIR(dest)) {
     dout(7) << "Cannot export to mds." << dest << " " << *dir << ": in stray directory" << dendl;
     return;
+  } else if (dir->inode->is_quiesced()) {
+    dout(7) << "Cannot export to mds." << dest << " " << *dir << ": is quiesced" << dendl;
+    return;
   }
 
   if (unlikely(g_conf()->mds_thrash_exports)) {
@@ -1068,6 +1071,10 @@ void Migrator::dispatch_export_dir(const MDRequestRef& mdr, int count)
     lov.add_rdlock(&dir->get_inode()->dirfragtreelock);
 
     if (!mds->locker->acquire_locks(mdr, lov, nullptr, {}, true)) {
+      /* if quiescelock cannot be wrlocked, we cannot block with dir frozen */
+      if (!mdr->is_wrlocked(&dir->get_inode()->quiescelock)) {
+        mdr->aborted = true;
+      }
       if (mdr->aborted)
 	export_try_cancel(dir);
       return;