Re: [PATCH v5 06/14] ntfs: update file operations

[Namjae Jeon]

On Tue, Jan 20, 2026 at 3:42 PM Christoph Hellwig <hch@xxxxxx> wrote:
>
> On Tue, Jan 20, 2026 at 02:11:24PM +0900, Namjae Jeon wrote:
> > By modifying iomap_begin, it seems possible to implement it using
> > iomap_seek_hole/data without introducing a new IOMAP_xxx type.
>
> Note that you can also use different iomap ops for different operations
> if needed.
Okay.
>
> > Since NTFS does not support multiple unwritten extents, all
> > pre-allocated regions must, in principle, be treated as DATA, not
> > HOLE. However, in the current implementation, region #2 is mapped as
> > IOMAP_UNWRITTEN, so iomap_seek_data incorrectly interprets this region
> > as a hole. It would be better to map region #2 as IOMAP_MAPPED for the
> > seek operation.
>
> So basically it optimizes for the case of appending on the end.
>
> Can you add the above to a code comment where you set IOMAP_UNWRITTEN?
I will do that. Thank you for the review!
>