On 12/4/25 12:07, Christoph Hellwig wrote:
On Thu, Dec 04, 2025 at 11:46:45AM +0100, Christian König wrote:
On 11/23/25 23:51, Pavel Begunkov wrote:
Add a file callback that maps a dmabuf for the given file and returns an opaque token of type struct dma_token representing the mapping.
I'm really scratching my head what you mean with that?
And why the heck would we need to pass a DMA-buf to a struct file?
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?
Regards, Christian.