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From:   Akihiko Odaki <akihiko.odaki@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        Jens Axboe <axboe@kernel.dk>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Akihiko Odaki <akihiko.odaki@gmail.com>
Subject: [PATCH] virtio-blk: Assign discard_granularity
Date:   Thu, 24 Feb 2022 18:38:02 +0900
Message-Id: <20220224093802.11348-1-akihiko.odaki@gmail.com>
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Virtual I/O Device (VIRTIO) Version 1.1
https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html
> discard_sector_alignment can be used by OS when splitting a request
> based on alignment.

According to Documentation/ABI/stable/sysfs-block, the corresponding
field in the kernel is, confusingly, discard_granularity, not
discard_alignment.

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
---
 drivers/block/virtio_blk.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index c443cd64fc9b..1fb3c89900e3 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -913,11 +913,9 @@ static int virtblk_probe(struct virtio_device *vdev)
 		blk_queue_io_opt(q, blk_size * opt_io_size);
 
 	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
-		q->limits.discard_granularity = blk_size;
-
 		virtio_cread(vdev, struct virtio_blk_config,
 			     discard_sector_alignment, &v);
-		q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
+		q->limits.discard_granularity = v ? v << SECTOR_SHIFT : 0;
 
 		virtio_cread(vdev, struct virtio_blk_config,
 			     max_discard_sectors, &v);
-- 
2.35.1