iotests: Fix 291 across more file systems

Depending on the granularity of holes and amount of metadata consumed
by a file, the 'disk size:' number of 'qemu-img info' is not reliable.
Adjust our test to use a different set of filters to avoid spurious
failures.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Fixes: cf2d1203dc
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200608195629.3299649-1-eblake@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
[eblake: fix merge conflict]
Signed-off-by: Eric Blake <eblake@redhat.com>

tests/qemu-iotests/291

@@ -79,7 +79,7 @@ echo
 
 # Only bitmaps from the active layer are copied
 $QEMU_IMG convert --bitmaps -O qcow2 "$TEST_IMG.orig" "$TEST_IMG"
-$QEMU_IMG info "$TEST_IMG" | _filter_img_info --format-specific
+_img_info --format-specific
 # But we can also merge in bitmaps from other layers.  This test is a bit
 # contrived to cover more code paths, in reality, you could merge directly
 # into b0 without going through tmp
@@ -89,7 +89,7 @@ $QEMU_IMG bitmap --add --merge b0 -b "$TEST_IMG.base" -F $IMGFMT \
 $QEMU_IMG bitmap --merge tmp -f $IMGFMT "$TEST_IMG" b0
 $QEMU_IMG bitmap --remove --image-opts \
     driver=$IMGFMT,file.driver=file,file.filename="$TEST_IMG" tmp
-$QEMU_IMG info "$TEST_IMG" | _filter_img_info --format-specific
+_img_info --format-specific
 echo "Check resulting qcow2 header extensions:"
 $PYTHON qcow2.py "$TEST_IMG" dump-header-exts
 

tests/qemu-iotests/291.out

@@ -43,7 +43,7 @@ qemu-img: Format driver 'raw' does not support bitmaps
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 10 MiB (10485760 bytes)
-disk size: 4.39 MiB
+cluster_size: 65536
 Format specific information:
     compat: 1.1
     compression type: zlib
@@ -63,7 +63,7 @@ Format specific information:
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 10 MiB (10485760 bytes)
-disk size: 4.48 MiB
+cluster_size: 65536
 Format specific information:
     compat: 1.1
     compression type: zlib