[PATCH] xen-blkfront: don't make discard-alignment mandatory
From: Roger Pau Monne <hidden>
Date: 2021-01-18 15:21:56
Also in:
lkml, xen-devel
Subsystem:
block layer, the rest, xen block subsystem, xen hypervisor interface · Maintainers:
Jens Axboe, Linus Torvalds, Roger Pau Monné, Juergen Gross, Stefano Stabellini
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 <redacted> Signed-off-by: Roger Pau Monné <redacted> --- Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Konrad Rzeszutek Wilk <redacted> Cc: "Roger Pau Monné" <redacted> Cc: Jens Axboe <axboe@kernel.dk> Cc: xen-devel@lists.xenproject.org Cc: linux-block@vger.kernel.org Cc: Arthur Borsboom <redacted> --- 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