Commit 3718d8ab65 ("block: Replace in_use
with operation blocker") broke the error path because it consumed
local_err instead of propagating it.
The caller has no way to know that the function failed. This caused
virtio-blk to start "successfully" even though there was a fatal
dataplane error.
Steps to reproduce:
$ qemu-system-x86_64 -enable-kvm -object iothread,id=iothread0 \
-drive if=none,id=drive0,file=a.img \
(qemu) drive_mirror drive0 /tmp/foo.img
(qemu) device_add virtio-blk-pci,iothread=iothread0,drive=drive0
Expected result:
Since the mirror block job is using drive0 it is not possible to start
virtio-blk data-plane.
device_add fails and the PCI adapter is not added.
Actual result:
device_add completes and the PCI adapter is added.
Cc: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
745a9bb9cd