diff --git a/block.c b/block.c index aaa387504e..957630b1c5 100644 --- a/block.c +++ b/block.c @@ -3787,6 +3787,29 @@ static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs, *shared = cumulative_shared_perms; } +static bool bdrv_reopen_can_attach(BlockDriverState *parent, + BdrvChild *child, + BlockDriverState *new_child, + Error **errp) +{ + AioContext *parent_ctx = bdrv_get_aio_context(parent); + AioContext *child_ctx = bdrv_get_aio_context(new_child); + GSList *ignore; + bool ret; + + ignore = g_slist_prepend(NULL, child); + ret = bdrv_can_set_aio_context(new_child, parent_ctx, &ignore, NULL); + g_slist_free(ignore); + if (ret) { + return ret; + } + + ignore = g_slist_prepend(NULL, child); + ret = bdrv_can_set_aio_context(parent, child_ctx, &ignore, errp); + g_slist_free(ignore); + return ret; +} + /* * Take a BDRVReopenState and check if the value of 'backing' in the * reopen_state->options QDict is valid or not. @@ -3838,14 +3861,11 @@ static int bdrv_reopen_parse_backing(BDRVReopenState *reopen_state, } /* - * TODO: before removing the x- prefix from x-blockdev-reopen we - * should move the new backing file into the right AioContext - * instead of returning an error. + * Check AioContext compatibility so that the bdrv_set_backing_hd() call in + * bdrv_reopen_commit() won't fail. */ if (new_backing_bs) { - if (bdrv_get_aio_context(new_backing_bs) != bdrv_get_aio_context(bs)) { - error_setg(errp, "Cannot use a new backing file " - "with a different AioContext"); + if (!bdrv_reopen_can_attach(bs, bs->backing, new_backing_bs, errp)) { return -EINVAL; } } diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245 index 7d9eb6285c..1001275a44 100755 --- a/tests/qemu-iotests/245 +++ b/tests/qemu-iotests/245 @@ -1015,18 +1015,16 @@ class TestBlockdevReopen(iotests.QMPTestCase): # neither of them can switch to the other AioContext def test_iothreads_error(self): self.run_test_iothreads('iothread0', 'iothread1', - "Cannot use a new backing file with a different AioContext") + "Cannot change iothread of active block backend") def test_iothreads_compatible_users(self): self.run_test_iothreads('iothread0', 'iothread0') def test_iothreads_switch_backing(self): - self.run_test_iothreads('iothread0', None, - "Cannot use a new backing file with a different AioContext") + self.run_test_iothreads('iothread0', None) def test_iothreads_switch_overlay(self): - self.run_test_iothreads(None, 'iothread0', - "Cannot use a new backing file with a different AioContext") + self.run_test_iothreads(None, 'iothread0') if __name__ == '__main__': iotests.main(supported_fmts=["qcow2"],