Re: [LSF/MM TOPIC] Discuss least bad options for resolving longterm-GUP usage by RDMA

From: Jason Gunthorpe
Date: Wed Feb 06 2019 - 13:52:46 EST


On Wed, Feb 06, 2019 at 10:35:04AM -0800, Matthew Wilcox wrote:

> > Admittedly, I'm coming in late to this conversation, but did I miss the
> > portion where that alternative was ruled out?
>
> That's my preferred option too, but the preponderance of opinion leans
> towards "We can't give people a way to make files un-truncatable".

I haven't heard an explanation why blocking ftruncate is worse than
giving people a way to break RDMA using process by calling ftruncate??

Isn't it exactly the same argument the other way?

Jason