Am 19.08.22 um 15:39 schrieb Jason Gunthorpe:
On Fri, Aug 19, 2022 at 03:33:04PM +0200, Christian König wrote:
So we could delete the try_buf and just rely on move being safe on
partially destroyed dma_buf's as part of the API design.
I think that might be the more defensive approach. A comment on the
dma_buf_move_notify() function should probably be a good idea.
IMHO, it is an anti-pattern. The caller should hold a strong reference
on an object before invoking any API surface. Upgrading a weak
reference to a strong reference requires the standard "try get" API.
But if you feel strongly I don't mind dropping the try_get around move.
Well I see it as well that both approaches are not ideal, but my gut feeling
tells me that just documenting that dma_buf_move_notify() can still be
called as long as the release callback wasn't called yet is probably the
better approach.
The comment would say something like:
"dma_resv_lock(), dma_buf_move_notify(), dma_resv_unlock() may be
called with a 0 refcount so long as ops->release() hasn't returned"
Which is a really abnormal API design, IMHO.
Mhm, Daniel or other do you have any opinion on that as well?
Thanks,
Christian.
Jason
