wic/filemap: handle FIGETBSZ failing

Some file systems don't support fetching the block size (notably the file system
Docker uses for containers), so handle the iotctl() failing and raise the
expected error.

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/scripts/lib/wic/filemap.py b/scripts/lib/wic/filemap.py
index 244c07a71cf7768195268fdb5dcd462232c8bf02..a3919fbcad8bd06a26f0ca6e9cc8f4f1260f489c 100644 (file)
--- a/scripts/lib/wic/filemap.py
+++ b/scripts/lib/wic/filemap.py
@@ -32,7 +32,10 @@ def get_block_size(file_obj):
     """
     # Get the block size of the host file-system for the image file by calling
     # the FIGETBSZ ioctl (number 2).
-    binary_data = fcntl.ioctl(file_obj, 2, struct.pack('I', 0))
+    try:
+        binary_data = fcntl.ioctl(file_obj, 2, struct.pack('I', 0))
+    except OSError:
+        raise IOError("Unable to determine block size")
     bsize = struct.unpack('I', binary_data)[0]
     if not bsize:
         import os