From 416cc9db01aa0cd9a10e994ffa56ca93a37afdef Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Tue, 24 Mar 2009 15:12:50 -0700
Subject: [PATCH] mds: avoid including caps in readdir items if snaprealm
 differs

Since the reply snaprealm starts at the _dir_ inode, we want to
exclude caps for any nested items if the realm differs.  Otherwise
the client is screwed...
---
 src/mds/CInode.cc | 10 +++++++++-
 src/mds/CInode.h  |  3 ++-
 src/mds/Server.cc | 10 +++++-----
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/mds/CInode.cc b/src/mds/CInode.cc
index de6b098bc709a..1d0b0a4eb853b 100644
--- a/src/mds/CInode.cc
+++ b/src/mds/CInode.cc
@@ -1341,12 +1341,19 @@ void CInode::decode_snap_blob(bufferlist& snapbl)
 
 
 bool CInode::encode_inodestat(bufferlist& bl, Session *session,
+			      SnapRealm *realm,
 			      snapid_t snapid, bool is_replay)
 {
   int client = session->inst.name.num();
 
   bool valid = true;
 
+  // do not issue caps if inode differs from readdir snaprealm
+  bool no_caps = (realm && snaprealm && realm != snaprealm);
+  if (no_caps)
+    dout(20) << "encode_inodestat realm=" << realm << " snaprealm " << snaprealm
+	     << " no_caps=" << no_caps << dendl;
+
   // pick a version!
   inode_t *oi = &inode;
   inode_t *pi = get_projected_inode();
@@ -1435,12 +1442,13 @@ bool CInode::encode_inodestat(bufferlist& bl, Session *session,
     e.cap.mseq = 0;
     e.cap.realm = 0;
   } else {
-    if (valid && !cap && is_auth()) {
+    if (!no_caps && valid && !cap && is_auth()) {
       // add a new cap
       cap = add_client_cap(client, session, &mdcache->client_rdcaps, find_snaprealm());
     }
 
     if (is_replay) {
+      assert(cap);
       // if this is a replayed request, check for a cap reconnect
       ceph_mds_cap_reconnect *rc = mdcache->get_replay_cap_reconnect(pi->ino, client);
       if (rc) {
diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 4215e1b98668e..c58e4c634f91f 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -441,7 +441,8 @@ private:
   
 
   // for giving to clients
-  bool encode_inodestat(bufferlist& bl, Session *session, snapid_t snapid=CEPH_NOSNAP, bool is_replay=false);
+  bool encode_inodestat(bufferlist& bl, Session *session, SnapRealm *realm,
+			snapid_t snapid=CEPH_NOSNAP, bool is_replay=false);
   void encode_cap_message(MClientCaps *m, Capability *cap);
 
 
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index a1447dc890d4e..4677cdd8308ed 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -733,10 +733,10 @@ void Server::set_trace_dist(Session *session, MClientReply *reply, CInode *in, C
     // snapbl
     realm = in->find_snaprealm();
     reply->snapbl = realm->get_snap_trace();
-    dout(10) << "set_trace_dist snaprealm " << *realm << dendl;
+    dout(10) << "set_trace_dist snaprealm " << *realm << " len=" << reply->snapbl.length() << dendl;
   }
 
-  in->encode_inodestat(bl, session, snapid, is_replay);
+  in->encode_inodestat(bl, session, NULL, snapid, is_replay);
   dout(20) << "set_trace_dist added snapid " << snapid << " " << *in << dendl;
 
   if (snapid != CEPH_NOSNAP && in == snapdiri) {
@@ -750,7 +750,7 @@ void Server::set_trace_dist(Session *session, MClientReply *reply, CInode *in, C
 
     // back to the live tree
     snapid = CEPH_NOSNAP;
-    in->encode_inodestat(bl, session, snapid);
+    in->encode_inodestat(bl, session, NULL, snapid);
     numi++;
     dout(20) << "set_trace_dist added snapid " << snapid << " " << *in << dendl;
 
@@ -2282,7 +2282,7 @@ void Server::handle_client_readdir(MDRequest *mdr)
 
     // inode
     dout(12) << "including inode " << *in << dendl;
-    bool valid = in->encode_inodestat(dnbl, mdr->session, snapid);
+    bool valid = in->encode_inodestat(dnbl, mdr->session, realm, snapid);
     assert(valid);
     numfiles++;
 
@@ -5275,7 +5275,7 @@ void Server::handle_client_lssnap(MDRequest *mdr)
     else
       ::encode(p->second->get_long_name(), dnbl);
     encode_infinite_lease(dnbl);
-    diri->encode_inodestat(dnbl, mdr->session, p->first);
+    diri->encode_inodestat(dnbl, mdr->session, realm, p->first);
     num++;
   }
 
-- 
2.39.5