mds: add drop cache command

qa/tasks/cephfs/test_misc.py

@@ -207,3 +207,74 @@ def test_dump_inode(self):
         info = self.fs.mds_asok(['dump', 'inode', '1'])
         assert(info['path'] == "/")
 
+    def _run_drop_cache_cmd(self, timeout, use_tell):
+        drop_res = None
+        if use_tell:
+            mds_id = self.fs.get_lone_mds_id()
+            drop_res = json.loads(
+                self.fs.mon_manager.raw_cluster_cmd("tell", "mds.{0}".format(mds_id),
+                                                    "cache", "drop", str(timeout)))
+        else:
+            drop_res = self.fs.mds_asok(["cache", "drop", str(timeout)])
+        return drop_res
+
+    def _drop_cache_command(self, timeout, use_tell=True):
+        self.mount_b.umount_wait()
+        ls_data = self.fs.mds_asok(['session', 'ls'])
+        self.assert_session_count(1, ls_data)
+
+        # create some files
+        self.mount_a.create_n_files("dc-dir/dc-file", 1000)
+        # drop cache
+        drop_res = self._run_drop_cache_cmd(timeout, use_tell)
+
+        self.assertTrue(drop_res['client_recall']['return_code'] == 0)
+        self.assertTrue(drop_res['flush_journal']['return_code'] == 0)
+
+    def _drop_cache_command_timeout(self, timeout, use_tell=True):
+        self.mount_b.umount_wait()
+        ls_data = self.fs.mds_asok(['session', 'ls'])
+        self.assert_session_count(1, ls_data)
+
+        # create some files
+        self.mount_a.create_n_files("dc-dir/dc-file-t", 1000)
+
+        # simulate client death and try drop cache
+        self.mount_a.kill()
+        drop_res = self._run_drop_cache_cmd(timeout, use_tell)
+
+        self.assertTrue(drop_res['client_recall']['return_code'] == -errno.ETIMEDOUT)
+        self.assertTrue(drop_res['flush_journal']['return_code'] == 0)
+
+        self.mount_a.kill_cleanup()
+        self.mount_a.mount()
+        self.mount_a.wait_until_mounted()
+
+    def test_drop_cache_command_asok(self):
+        """
+        Basic test for checking drop cache command using admin socket.
+        Note that the cache size post trimming is not checked here.
+        """
+        self._drop_cache_command(10, use_tell=False)
+
+    def test_drop_cache_command_tell(self):
+        """
+        Basic test for checking drop cache command using tell interface.
+        Note that the cache size post trimming is not checked here.
+        """
+        self._drop_cache_command(10)
+
+    def test_drop_cache_command_timeout_asok(self):
+        """
+        Check drop cache command with non-responding client using admin
+        socket. Note that the cache size post trimming is not checked here.
+        """
+        self._drop_cache_command_timeout(5, use_tell=False)
+
+    def test_drop_cache_command_timeout_tell(self):
+        """
+        Check drop cache command with non-responding client using tell
+        interface. Note that the cache size post trimming is not checked
+        here.
+        """
+        self._drop_cache_command_timeout(5)

src/mds/MDCache.cc

@@ -7524,7 +7524,7 @@ void MDCache::check_memory_usage()
 
   if (cache_toofull()) {
     last_recall_state = clock::now();
-    mds->server->recall_client_state();
+    mds->server->recall_client_state(-1.0, false, nullptr);
   }
 
   // If the cache size had exceeded its limit, but we're back in bounds
@@ -12025,7 +12025,7 @@ void MDCache::show_cache()
     show_func(p.second);
 }
 
-int MDCache::cache_status(Formatter *f)
+void MDCache::cache_status(Formatter *f)
 {
   f->open_object_section("cache");
 
@@ -12034,7 +12034,6 @@ int MDCache::cache_status(Formatter *f)
   f->close_section();
 
   f->close_section();
-  return 0;
 }
 
 void MDCache::dump_tree(CInode *in, const int cur_depth, const int max_depth, Formatter *f) 

src/mds/MDCache.h

@@ -1207,7 +1207,7 @@ class MDCache {
   int dump_cache(Formatter *f);
   void dump_tree(CInode *in, const int cur_depth, const int max_depth, Formatter *f);
 
-  int cache_status(Formatter *f);
+  void cache_status(Formatter *f);
 
   void dump_resolve_status(Formatter *f) const;
   void dump_rejoin_status(Formatter *f) const;

src/mds/MDSDaemon.cc

@@ -244,6 +244,11 @@ void MDSDaemon::set_up_admin_socket()
                                      asok_hook,
                                      "show cache status");
   ceph_assert(r == 0);
+  r = admin_socket->register_command("cache drop",
+                                     "cache drop name=timeout,type=CephInt,range=1",
+                                     asok_hook,
+                                     "drop cache");
+  ceph_assert(r == 0);
   r = admin_socket->register_command("dump tree",
 				     "dump tree "
 				     "name=root,type=CephString,req=true "
@@ -696,6 +701,9 @@ COMMAND("heap " \
 	"name=heapcmd,type=CephChoices,strings=dump|start_profiler|stop_profiler|release|stats", \
 	"show heap usage info (available only if compiled with tcmalloc)", \
 	"mds", "*", "cli,rest")
+COMMAND("cache drop name=timeout,type=CephInt,range=1", "trim cache and optionally "
+	"request client to release all caps and flush the journal", "mds",
+	"r", "cli,rest")
 };
 
 
@@ -861,8 +869,8 @@ int MDSDaemon::_handle_command(
     else {
       bool handled;
       try {
-	handled = mds_rank->handle_command(cmdmap, m, &r, &ds, &ss,
-					   need_reply);
+        handled = mds_rank->handle_command(cmdmap, m, &r, &ds, &ss,
+                                           run_later, need_reply);
 	if (!handled) {
 	  // MDSDaemon doesn't know this command
 	  ss << "unrecognized command! " << prefix;