Messages in this thread | | | Subject | Re: [PATCH] xen-blkfront: don't make discard-alignment mandatory | From | Jürgen Groß <> | Date | Tue, 19 Jan 2021 08:43:01 +0100 |
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On 18.01.21 16:15, Roger Pau Monne wrote: > Don't require the discard-alignment xenstore node to be present in > order to correctly setup the feature. This can happen with versions of > QEMU that only write the discard-granularity but not the > discard-alignment node. > > Assume discard-alignment is 0 if not present. While there also fix the > logic to not enable the discard feature if discard-granularity is not > present. > > Reported-by: Arthur Borsboom <arthurborsboom@gmail.com> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> > --- > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> > Cc: Juergen Gross <jgross@suse.com> > Cc: Stefano Stabellini <sstabellini@kernel.org> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: "Roger Pau Monné" <roger.pau@citrix.com> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: xen-devel@lists.xenproject.org > Cc: linux-block@vger.kernel.org > Cc: Arthur Borsboom <arthurborsboom@gmail.com> > --- > drivers/block/xen-blkfront.c | 25 +++++++++++++------------ > 1 file changed, 13 insertions(+), 12 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index 5265975b3fba..5a93f7cc2939 100644 > --- a/drivers/block/xen-blkfront.c > +++ b/drivers/block/xen-blkfront.c > @@ -2179,22 +2179,23 @@ static void blkfront_closing(struct blkfront_info *info) > > static void blkfront_setup_discard(struct blkfront_info *info) > { > - int err; > - unsigned int discard_granularity; > - unsigned int discard_alignment; > + unsigned int discard_granularity = 0; > + unsigned int discard_alignment = 0; > + unsigned int discard_secure = 0; > > - info->feature_discard = 1; > - err = xenbus_gather(XBT_NIL, info->xbdev->otherend, > + xenbus_gather(XBT_NIL, info->xbdev->otherend, > "discard-granularity", "%u", &discard_granularity, > "discard-alignment", "%u", &discard_alignment, > + "discard-secure", "%u", &discard_secure, > NULL);
This would mean that "discard-secure" will be evaluated only if the other two items are set in Xenstore. From blkif.h I can't see this is required, and your patch is modifying today's behavior in this regard.
You might want to have three xenbus_read_unsigned() calls instead.
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] | |