iotests: Prepare for refcount_bits option

Some tests do not work well with certain refcount widths (i.e. you
cannot create internal snapshots with refcount_bits=1), so make those
widths unsupported.

Furthermore, add another filter to _filter_img_create in common.filter
which filters out the refcount_bits value.

This is necessary for test 079, which does actually work with any
refcount width, but invoking qemu-img directly leads to the
refcount_bits value being visible in the output; use _make_test_img
instead which will filter it out.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/qemu-iotests/026 b/tests/qemu-iotests/026
index df2884b..0fc3244 100755
--- a/tests/qemu-iotests/026
+++ b/tests/qemu-iotests/026
@@ -46,6 +46,13 @@ _supported_proto file
 _supported_os Linux
 _default_cache_mode "writethrough"
 _supported_cache_modes "writethrough" "none"
+# The refcount table tests expect a certain minimum width for refcount entries
+# (so that the refcount table actually needs to grow); that minimum is 16 bits,
+# being the default refcount entry width.
+# 32 and 64 bits do not work either, however, due to different leaked cluster
+# count on error.
+# Thus, the only remaining option is refcount_bits=16.
+_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 echo "Errors while writing 128 kB"
 echo