librbd: validate order before creating an image

The value must be passed, and it shouldn't be below 4k
(enforced by the command line tool already) or above the
range expressible in the header.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/src/librbd.cc b/src/librbd.cc
index ebe7db2cd912e65cd83904e8d4751f46a45c2536..0d357fa222cb56c67f8cafcccf7d2e785bfa2192 100644 (file)
--- a/src/librbd.cc
+++ b/src/librbd.cc
@@ -992,6 +992,14 @@ int create(IoCtx& io_ctx, const char *imgname, uint64_t size, int *order)
     return -EEXIST;
   }
 
+  if (!order)
+    return -EINVAL;
+
+  if (*order && (*order > 255 || *order < 12)) {
+    lderr(cct) << "order must be in the range [12, 255]" << dendl;
+    return -EDOM;
+  }
+
   uint64_t bid;
   string dir_info = RBD_INFO;
   r = rbd_assign_bid(io_ctx, dir_info, &bid);