devices: Avoid using assert() to catch misconfiguration

--HG--
extra : convert_revision : 2c6710e01a4402793a2e0eafcc829df19d03dda3

1 files changed, 2 insertions, 1 deletions

diff --git a/src/dev/disk_image.cc b/src/dev/disk_image.cc
index b8386bc3d..792a31204 100644
--- a/src/dev/disk_image.cc
+++ b/src/dev/disk_image.cc
@@ -171,7 +171,8 @@ CowDiskImage::CowDiskImage(const Params *p)
         init(p->table_size);
     } else {
         if (!open(filename)) {
-            assert(!p->read_only && "why have a non-existent read only file?");
+            if (p->read_only)
+                fatal("could not open read-only file");
             init(p->table_size);
         }