Print desired mode when device opening fails.

diff --git a/libexfat/io.c b/libexfat/io.c
index 3d63fa9..25988f0 100644 (file)
--- a/libexfat/io.c
+++ b/libexfat/io.c
@@ -39,7 +39,8 @@ int exfat_open(const char* spec, int ro)
        fd = open(spec, ro ? O_RDONLY : O_RDWR);
        if (fd < 0)
        {
-               exfat_error("failed to open `%s'", spec);
+               exfat_error("failed to open `%s' in read-%s mode", spec,
+                               ro ? "only" : "write");
                return -1;
        }
        if (fstat(fd, &stbuf) != 0)