Re: [PATCH v4 01/12] mm/shmem: Introduce F_SEAL_INACCESSIBLE

On 3/7/22 14:26, Chao Peng wrote:

quoted

In pseudo-Rust, this is the difference between:

fn convert_to_private(in: &mut Memfd)

and

fn convert_to_private(in: Memfd) -> PrivateMemoryFd

This doesn't map particularly nicely to the kernel, though.

I understand this Rust semantics and the difficulty to handle races.
Probably we should not expose F_SEAL_INACCESSIBLE to userspace, instead
we can use a new in-kernel flag to indicate the same thing. That flag
should be set only when the memfd is created with MFD_INACCESSIBLE.

Yes, I like this.

Paolo