On 1/4/26 02:42, Ming Lei wrote: > On Thu, Dec 04, 2025 at 02:10:25PM +0100, Christoph Hellwig wrote: >> On Thu, Dec 04, 2025 at 12:09:46PM +0100, Christian König wrote: >>>> I find the naming pretty confusing a well. But what this does is to >>>> tell the file system/driver that it should expect a future >>>> read_iter/write_iter operation that takes data from / puts data into >>>> the dmabuf passed to this operation. >>> >>> That explanation makes much more sense. >>> >>> The remaining question is why does the underlying file system / driver >>> needs to know that it will get addresses from a DMA-buf? >> >> This eventually ends up calling dma_buf_dynamic_attach and provides >> a way to find the dma_buf_attachment later in the I/O path. > > Maybe it can be named as ->dma_buf_attach()? For wiring dma-buf and the > importer side(nvme).
Yeah that would make it much more cleaner. Also some higher level documentation would certainly help. > But I am wondering why not make it as one subsystem interface, such as nvme > ioctl, then the whole implementation can be simplified a lot. It is reasonable > because subsystem is exactly the side for consuming/importing the dma-buf. Yeah that it might be better if it's more nvme specific came to me as well. Regards, Christian. > > > Thanks, > Ming >
