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@xxxxxxxxx>
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Cc: linux-block@xxxxxxxxxxxxxxx
Cc: Arthur Borsboom <arthurborsboom@xxxxxxxxx>
---
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);
- if (!err) {
- info->discard_granularity = discard_granularity;
- info->discard_alignment = discard_alignment;
- }
- info->feature_secdiscard =
- !!xenbus_read_unsigned(info->xbdev->otherend, "discard-secure",
- 0);
+
+ if (!discard_granularity)
+ return;
+
+ info->feature_discard = 1;
+ info->discard_granularity = discard_granularity;
+ info->discard_alignment = discard_alignment;
+ info->feature_secdiscard = !!discard_secure;
}
static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
--
2.29.2
