diff options
| author | Christoph Hellwig <hch@lst.de> | 2022-04-18 06:53:07 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-05-03 10:38:50 -0600 |
| commit | 62952cc5bccd89b76d710de1d0b43244af0f2903 (patch) | |
| tree | 5345281eeb00cffa1579beea26b274c76ebe9a2e /drivers/block/virtio_blk.c | |
| parent | fb749a87f4536d2fa86ea135ae4eff1072903438 (diff) | |
virtio_blk: fix the discard_granularity and discard_alignment queue limits
The discard_alignment queue limit is named a bit misleading means the
offset into the block device at which the discard granularity starts.
On the other hand the discard_sector_alignment from the virtio 1.1 looks
similar to what Linux uses as discard granularity (even if not very well
described):
"discard_sector_alignment can be used by OS when splitting a request
based on alignment. "
And at least qemu does set it to the discard granularity.
So stop setting the discard_alignment and use the virtio
discard_sector_alignment to set the discard granularity.
Fixes: 1f23816b8eb8 ("virtio_blk: add discard and write zeroes support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220418045314.360785-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/virtio_blk.c')
| -rw-r--r-- | drivers/block/virtio_blk.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 6ccf15253dee..d624cc8eddc3 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -867,11 +867,12 @@ 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; + if (v) + q->limits.discard_granularity = v << SECTOR_SHIFT; + else + q->limits.discard_granularity = blk_size; virtio_cread(vdev, struct virtio_blk_config, max_discard_sectors, &v); |