ceph: check migrate seq before changing auth cap

We may receive old request reply from the exporter MDS after receiving
the importer MDS' cap import message.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 54c290b083ab..790f88b15daf 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -612,9 +612,11 @@ retry:
                 __cap_delay_requeue(mdsc, ci);
         }
 
-        if (flags & CEPH_CAP_FLAG_AUTH)
-                ci->i_auth_cap = cap;
-        else if (ci->i_auth_cap == cap) {
+        if (flags & CEPH_CAP_FLAG_AUTH) {
+                if (ci->i_auth_cap == NULL ||
+                    ceph_seq_cmp(ci->i_auth_cap->mseq, mseq) < 0)
+                        ci->i_auth_cap = cap;
+        } else if (ci->i_auth_cap == cap) {
                 ci->i_auth_cap = NULL;
                 spin_lock(&mdsc->cap_dirty_lock);
                 if (!list_empty(&ci->i_dirty_item)) {