fixes in ceph tests, add linearity plot
diff --git a/wally/utils.py b/wally/utils.py
index 36601cd..8603f58 100644
--- a/wally/utils.py
+++ b/wally/utils.py
@@ -92,10 +92,10 @@
 
 def ssize_to_b(ssize):
     try:
-        ssize = ssize.lower()
+        if isinstance(ssize, (int, long)):
+            return ssize
 
-        if ssize.endswith("b"):
-            ssize = ssize[:-1]
+        ssize = ssize.lower()
         if ssize[-1] in SMAP:
             return int(ssize[:-1]) * SMAP[ssize[-1]]
         return int(ssize)