On Tue, Sep 21, 2021 at 09:29:25AM +0100, Christoph Hellwig wrote:

On Fri, Sep 17, 2021 at 06:30:55PM -0700, Darrick J. Wong wrote:

quoted

From: Darrick J. Wong <djwong@kernel.org>

Create a function that ensures that the storage backing part of a file
contains zeroes and will not trip over old media errors if the contents
are re-read.

I don't think this has anything to do with direct I/O, so I'd rather
not have it clutter direct-io.c.  Also do we really want to wait
synchronously for every bio instead of batching them up?  Especially
as a simple bio_chain is probably all that is needed.

__blkdev_issue_zeroout looks appropriate for chaining.  I'll move the
zeroout routine into a new lowlevel.c file, since this isn't buffered io
either.

--D