Hi all!
As reported in https://bugzilla.redhat.com/show_bug.cgi?id=2004812
backup don't work when copy-before-write is not white-listed.
Yes, we do need copy-before-write filter for backup to work (like we
always use copy-on-read filter in block-stream).
The problem is that in bdrv_insert_node() (called to insert filters
internally) we use bdrv_open(), which does a lot of things we don't need
for internal node creation and among them check the white-list.
Backup job should of course work when copy-before-write is not
white-listed. As well, block-stream should work with not-white-listed
copy-on-read. White-list is for user, not for internal implementation.
Following Kevin's suggestion fix the problem by implementing a version
of bdrv_new_open_driver() that supports QDict of options, and use it
instead of bdrv_open().
Vladimir Sementsov-Ogievskiy (5):
block: implement bdrv_new_open_driver_opts()
block: bdrv_insert_node(): fix and improve error handling
block: bdrv_insert_node(): doc and style
block: bdrv_insert_node(): don't use bdrv_open()
iotests/image-fleecing: declare requirement of copy-before-write
include/block/block.h | 4 ++
block.c | 77 ++++++++++++++++++++-----
tests/qemu-iotests/tests/image-fleecing | 1 +
3 files changed, 68 insertions(+), 14 deletions(-)
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2.29.2