Re: [PATCH v2] file-posix: fix cache.direct=on check for zoned block devices

On Thu, Jun 18, 2026 at 11:00:25AM -0400, Stefan Hajnoczi wrote:
> On Wed, Jun 17, 2026 at 03:36:58PM +0200, Niklas Cassel wrote:
> > For zoned block devices with SWR zones, the order of the writes must be
> > maintained to avoid write not at write pointer errors.
> > Thus, cache.direct=on must be used to bypass the page cache, since the
> > page cache uses write-back caching, where the physical order of the writes
> > is not guaranteed.
> > 
> > There is already a check for cache.direct=on in raw_open_common(),
> > however, this check is done before raw_refresh_zoned_limits() has been
> > called (which initializes bs->bl.zoned), so it is currently dead code.
> > 
> > Fix this by moving the check to raw_refresh_zoned_limits(), such that the
> > check is done after bs->bl.zoned has been initialized.
> > 
> > Reviewed-by: Damien Le Moal <[email protected]>
> > Reviewed-by: Dmitry Fomichev <[email protected]>
> > Fixes: 774c726ceb2a ("block: add zoned BlockDriver check to block layer")
> > Signed-off-by: Niklas Cassel <[email protected]>
> > ---
> > Changes since v1:
> > -Picked up tags from Damien and Dmitry
> > -Modified existing code comment to use plural instead of singular
> > 
> >  block/file-posix.c | 22 ++++++++++------------
> >  1 file changed, 10 insertions(+), 12 deletions(-)
> 
> Reviewed-by: Stefan Hajnoczi <[email protected]>

Gentle ping on this patch.

Would be nice if anyone could pick it up :)


Kind regards,
Niklas