ceph: handle ESTALE properly; on receipt send to authority if it wasn't

Signed-off-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

2 files changed, 35 insertions, 8 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index a546e0ddb8e3..34d215ff4c82 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1628,6 +1628,15 @@ static int __prepare_send_request(struct ceph_mds_client *mdsc,
 
         req->r_mds = mds;
         req->r_attempts++;
+        if (req->r_inode) {
+                struct ceph_cap *cap =
+                        ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
+
+                if (cap)
+                        req->r_sent_on_mseq = cap->mseq;
+                else
+                        req->r_sent_on_mseq = -1;
+        }
         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
 
@@ -1962,21 +1971,39 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
         result = le32_to_cpu(head->result);
 
         /*
-         * Tolerate 2 consecutive ESTALEs from the same mds.
-         * FIXME: we should be looking at the cap migrate_seq.
+         * Handle an ESTALE
+         * if we're not talking to the authority, send to them
+         * if the authority has changed while we weren't looking,
+         * send to new authority
+         * Otherwise we just have to return an ESTALE
          */
         if (result == -ESTALE) {
-                req->r_direct_mode = USE_AUTH_MDS;
-                req->r_num_stale++;
-                if (req->r_num_stale <= 2) {
+                dout("got ESTALE on request %llu", req->r_tid);
+                if (!req->r_inode) ; //do nothing; not an authority problem
+                else if (req->r_direct_mode != USE_AUTH_MDS) {
+                        dout("not using auth, setting for that now");
+                        req->r_direct_mode = USE_AUTH_MDS;
                         __do_request(mdsc, req);
                         mutex_unlock(&mdsc->mutex);
                         goto out;
+                } else  {
+                        struct ceph_inode_info *ci = ceph_inode(req->r_inode);
+                        struct ceph_cap *cap =
+                                ceph_get_cap_for_mds(ci, req->r_mds);;
+
+                        dout("already using auth");
+                        if ((!cap || cap != ci->i_auth_cap) ||
+                            (cap->mseq != req->r_sent_on_mseq)) {
+                                dout("but cap changed, so resending");
+                                __do_request(mdsc, req);
+                                mutex_unlock(&mdsc->mutex);
+                                goto out;
+                        }
                 }
-        } else {
-                req->r_num_stale = 0;
+                dout("have to return ESTALE on request %llu", req->r_tid);
         }
 
+
         if (head->safe) {
                 req->r_got_safe = true;
                 __unregister_request(mdsc, req);
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index c86be30e8707..ab7e89f5e344 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -208,8 +208,8 @@ struct ceph_mds_request {
 
         int               r_attempts;   /* resend attempts */
         int               r_num_fwd;    /* number of forward attempts */
-        int               r_num_stale;
         int               r_resend_mds; /* mds to resend to next, if any*/
+        u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 
         struct kref       r_kref;
         struct list_head  r_wait;