Re: [RFC PATCH 2/2] mm, fs: daxfile, an interface for byte-addressable updates to pmem

From: Ross Zwisler
Date: Tue Jun 20 2017 - 11:43:07 EST

On Mon, Jun 19, 2017 at 10:22:14PM -0700, Darrick J. Wong wrote:
> Fourth, the VFS entry points for things like read, write, truncate,
> utimes, fallocate, etc. all just bail out if S_IOMAP_FROZEN is set on a
> file, so that the block map cannot be modified. mmap is still allowed,
> as we've discussed. /Maybe/ we can allow fallocate to extend a file
> with zeroed extents (it will be slow) as I've heard murmurs about
> wanting to be able to extend a file, maybe not.

Read and write should still be allowed, right?