mds: cap client recall to min caps per client

Fixes: http://tracker.ceph.com/issues/21575
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

diff --git a/qa/tasks/cephfs/test_client_limits.py b/qa/tasks/cephfs/test_client_limits.py
index b06d2a1d233fa0dc5fcecb18fe134942f8171750..14ac2c4082666a4db834309f7873eec434a5ea03 100644 (file)
--- a/qa/tasks/cephfs/test_client_limits.py
+++ b/qa/tasks/cephfs/test_client_limits.py
@@ -29,7 +29,7 @@ class TestClientLimits(CephFSTestCase):
     REQUIRE_KCLIENT_REMOTE = True
     CLIENTS_REQUIRED = 2
 
-    def _test_client_pin(self, use_subdir):
+    def _test_client_pin(self, use_subdir, open_files):
         """
         When a client pins an inode in its cache, for example because the file is held open,
         it should reject requests from the MDS to trim these caps.  The MDS should complain
@@ -39,13 +39,16 @@ class TestClientLimits(CephFSTestCase):
         :param use_subdir: whether to put test files in a subdir or use root
         """
 
-        cache_size = 100
-        open_files = 200
+        cache_size = open_files/2
 
         self.set_conf('mds', 'mds cache size', cache_size)
         self.fs.mds_fail_restart()
         self.fs.wait_for_daemons()
 
+        mds_min_caps_per_client = int(self.fs.get_config("mds_min_caps_per_client"))
+        self.assertTrue(open_files >= mds_min_caps_per_client)
+        mds_max_ratio_caps_per_client = float(self.fs.get_config("mds_max_ratio_caps_per_client"))
+
         mount_a_client_id = self.mount_a.get_global_id()
         path = "subdir/mount_a" if use_subdir else "mount_a"
         open_proc = self.mount_a.open_n_background(path, open_files)
@@ -62,8 +65,7 @@ class TestClientLimits(CephFSTestCase):
         # MDS should not be happy about that, as the client is failing to comply
         # with the SESSION_RECALL messages it is being sent
         mds_recall_state_timeout = float(self.fs.get_config("mds_recall_state_timeout"))
-        self.wait_for_health("MDS_CLIENT_RECALL",
-                mds_recall_state_timeout + 10)
+        self.wait_for_health("MDS_CLIENT_RECALL", mds_recall_state_timeout+10)
 
         # We can also test that the MDS health warning for oversized
         # cache is functioning as intended.
@@ -82,19 +84,30 @@ class TestClientLimits(CephFSTestCase):
 
         # The remaining caps should comply with the numbers sent from MDS in SESSION_RECALL message,
         # which depend on the caps outstanding, cache size and overall ratio
-        self.wait_until_equal(
-            lambda: self.get_session(mount_a_client_id)['num_caps'],
-            int(open_files * 0.2),
-            timeout=30,
-            reject_fn=lambda x: x < int(open_files*0.2))
+        def expected_caps():
+            num_caps = self.get_session(mount_a_client_id)['num_caps']
+            if num_caps < mds_min_caps_per_client:
+                raise
+            elif num_caps == mds_min_caps_per_client:
+                return True
+            elif num_caps == int((1.0-mds_max_ratio_caps_per_client)*(open_files+2)):
+                return True
+            else:
+                return False
+
+        self.wait_until_true(expected_caps, timeout=60)
 
     @needs_trimming
     def test_client_pin_root(self):
-        self._test_client_pin(False)
+        self._test_client_pin(False, 400)
 
     @needs_trimming
     def test_client_pin(self):
-        self._test_client_pin(True)
+        self._test_client_pin(True, 800)
+
+    @needs_trimming
+    def test_client_pin_mincaps(self):
+        self._test_client_pin(True, 200)
 
     def test_client_release_bug(self):
         """

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 3c339210fc98018d06c7426d6e3f953ac4836b28..1b95991d5d61fce01c48b6be885101fd63795a54 100644 (file)
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -1113,14 +1113,12 @@ void Server::recall_client_state(void)
             << ", leases " << session->leases.size()
             << dendl;
 
-    if (session->caps.size() > min_caps_per_client) {  
-      uint64_t newlim = MIN((session->caps.size() * ratio), max_caps_per_client);
-      if (session->caps.size() > newlim) {
-          MClientSession *m = new MClientSession(CEPH_SESSION_RECALL_STATE);
-          m->head.max_caps = newlim;
-          mds->send_message_client(m, session);
-          session->notify_recall_sent(newlim);
-      }
+    uint64_t newlim = MAX(MIN((session->caps.size() * ratio), max_caps_per_client), min_caps_per_client);
+    if (session->caps.size() > newlim) {
+      MClientSession *m = new MClientSession(CEPH_SESSION_RECALL_STATE);
+      m->head.max_caps = newlim;
+      mds->send_message_client(m, session);
+      session->notify_recall_sent(newlim);
     }
   }
 }