When invoking block-export-add with some iothread and
fixed-iothread=false, and changing the node's iothread fails, the error
is supposed to be ignored.
However, it is still stored in *errp, which is wrong. If a second error
occurs, the "*errp must be NULL" assertion in error_setv() fails:
qemu-system-x86_64: ../util/error.c:59: error_setv: Assertion
`*errp == NULL' failed.
So if fixed-iothread=false, we should ignore the error by passing NULL
to bdrv_try_set_aio_context().
Fixes: f51d23c80af73c95e0ce703ad06a300f1b3d63ef
("block/export: add iothread and fixed-iothread options")
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210624083825.29224-2-mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
8573823f3b