mds: handle race of freezing auth pin

Linkage of rename source dentry may change during freezing auth
pin for the rename source inode. So we may freeze auth pin for
the wrong inode.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index 1da958316d030f962d325a8f99077553b3693be4..8fc5c61e4f100ecbf6db9aa02aedc407a495dc19 100644 (file)
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -330,8 +330,16 @@ bool Locker::acquire_locks(MDRequestRef& mdr,
 
     dout(10) << " must authpin " << *object << dendl;
 
-    if (mdr->is_auth_pinned(object)) 
-      continue;
+    if (mdr->is_auth_pinned(object)) {
+      if (object != (MDSCacheObject*)auth_pin_freeze)
+       continue;
+      if (mdr->more()->is_remote_frozen_authpin) {
+       if (mdr->more()->rename_inode == auth_pin_freeze)
+         continue;
+       // unfreeze auth pin for the wrong inode
+       mustpin_remote[mdr->more()->rename_inode->authority().first].size();
+      }
+    }
     
     if (!object->is_auth()) {
       if (!mdr->locks.empty())

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 2d3584933b8965ccb8d90c470171f89eb895785c..a8e1ec63e783d2e67bedb94de9cde6e5ff2fa180 100644 (file)
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -2076,11 +2076,10 @@ void Server::handle_slave_auth_pin(MDRequestRef& mdr)
     MDSCacheObjectInfo info;
     (*p)->set_object_info(info);
     reply->get_authpins().push_back(info);
+    if (*p == (MDSCacheObject*)auth_pin_freeze)
+      auth_pin_freeze->set_object_info(reply->get_authpin_freeze());
   }
 
-  if (auth_pin_freeze)
-    auth_pin_freeze->set_object_info(reply->get_authpin_freeze());
-
   if (wouldblock)
     reply->mark_error_wouldblock();
   if (readonly)
@@ -2115,6 +2114,16 @@ void Server::handle_slave_auth_pin_ack(MDRequestRef& mdr, MMDSSlaveRequest *ack)
     pinned.insert(object);
   }
 
+  // removed frozen auth pin ?
+  if (mdr->more()->is_remote_frozen_authpin &&
+      ack->get_authpin_freeze() == MDSCacheObjectInfo()) {
+    auto p = mdr->remote_auth_pins.find(mdr->more()->rename_inode);
+    assert(p != mdr->remote_auth_pins.end());
+    if (p->second == from) {
+      mdr->more()->is_remote_frozen_authpin = false;
+    }
+  }
+
   // removed auth pins?
   map<MDSCacheObject*, mds_rank_t>::iterator p = mdr->remote_auth_pins.begin();
   while (p != mdr->remote_auth_pins.end()) {