get_features requires md_lock and snap_lock to be held

diff --git a/src/librbd/internal.cc b/src/librbd/internal.cc
index cdac5a7388a06854a5e090ce8543fc354ddc94ee..7a799eaa70b46a93251864647461430cca9722a2 100644 (file)
--- a/src/librbd/internal.cc
+++ b/src/librbd/internal.cc
@@ -515,14 +515,14 @@ namespace librbd {
       return r;
 
     uint64_t features;
+    Mutex::Locker l(ictx->md_lock);
+    Mutex::Locker l2(ictx->snap_lock);
     ictx->get_features(ictx->snap_id, &features);
     if ((features & RBD_FEATURE_LAYERING) == 0) {
       lderr(ictx->cct) << "snap_unprotect: image must support layering"
                       << dendl;
       return -ENOSYS;
     }
-    Mutex::Locker l(ictx->md_lock);
-    Mutex::Locker l2(ictx->snap_lock);
     snap_t snap_id = ictx->get_snap_id(snap_name);
     if (snap_id == CEPH_NOSNAP)
       return -ENOENT;