Re: [PATCH 2/7] FS-Cache: Add notification of page becoming writable to VMA ops

Anton Altaparmakov
2006-04-20T18:27:58Z

On Thu, 20 Apr 2006, Zach Brown wrote:
> David Howells wrote:
> > The attached patch adds a new VMA operation to notify a filesystem or other
> > driver about the MMU generating a fault because userspace attempted to write
> > to a page mapped through a read-only PTE.
>
> This will almost certainly help OCFS2 get shared writable mmap() right,
> too, though it probably won't be the whole story.

This is also required by NTFS for a correct implementation of "mmap write
into sparse region on ntfs volume with cluster size > PAGE_CACHE_SIZE".

Best regards,

Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer, http://www.linux-ntfs.org/