1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index f11b839166ef..0f260a6e97c4 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -70,6 +70,14 @@
 #define RBD_IMAGE_ID_LEN_MAX    64
 #define RBD_OBJ_PREFIX_LEN_MAX  64
 
+/* Feature bits */
+
+#define RBD_FEATURE_LAYERING      1
+
+/* Features supported by this (client software) implementation. */
+
+#define RBD_FEATURES_ALL          (0)
+
 /*
  * An RBD device name will be "rbd#", where the "rbd" comes from
  * RBD_DRV_NAME above, and # is a unique integer identifier.
@@ -2226,6 +2234,7 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
                 __le64 features;
                 __le64 incompat;
         } features_buf = { 0 };
+        u64 incompat;
         int ret;
 
         ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name,
@@ -2236,6 +2245,11 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
         dout("%s: rbd_req_sync_exec returned %d\n", __func__, ret);
         if (ret < 0)
                 return ret;
+
+        incompat = le64_to_cpu(features_buf.incompat);
+        if (incompat & ~RBD_FEATURES_ALL)
+                return -ENOTSUPP;
+
         *snap_features = le64_to_cpu(features_buf.features);
 
         dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
@@ -2977,7 +2991,7 @@ static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
         if (ret < 0)
                 goto out_err;
 
-        /* Get the features for the image */
+        /* Get the and check features for the image */
 
         ret = rbd_dev_v2_features(rbd_dev);
         if (ret < 0)