ceph: fix snaptrace decoding on cap migration between mds

This was simply broken.  Apparently at some point we thought about putting
the snaptrace in the middle section, but didn't.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index bb846164addc..9afa8d37a6e3 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2608,6 +2608,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
         u64 size, max_size;
         u64 tid;
         int check_caps = 0;
+        void *snaptrace;
         int r;
 
         dout("handle_caps from mds%d\n", mds);
@@ -2617,6 +2618,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
         if (msg->front.iov_len < sizeof(*h))
                 goto bad;
         h = msg->front.iov_base;
+        snaptrace = h + 1;
         op = le32_to_cpu(h->op);
         vino.ino = le64_to_cpu(h->ino);
         vino.snap = CEPH_NOSNAP;
@@ -2651,8 +2653,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 
         case CEPH_CAP_OP_IMPORT:
                 handle_cap_import(mdsc, inode, h, session,
-                                  msg->middle,
-                                  le32_to_cpu(h->snap_trace_len));
+                                  snaptrace, le32_to_cpu(h->snap_trace_len));
                 check_caps = 1; /* we may have sent a RELEASE to the old auth */
                 goto done;
         }