Support configuring the BLK_FEAT_ORDERED_HWQ flag in the null_blk driver to
make it easier to test write pipelining
Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/block/null_blk/main.c | 4 ++++
drivers/block/null_blk/null_blk.h | 1 +
2 files changed, 5 insertions(+)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 91642c9a3b29..86d72979d899 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -475,6 +475,7 @@ NULLB_DEVICE_ATTR(fua, bool, NULL);
NULLB_DEVICE_ATTR(rotational, bool, NULL);
NULLB_DEVICE_ATTR(badblocks_once, bool, NULL);
NULLB_DEVICE_ATTR(badblocks_partial_io, bool, NULL);
+NULLB_DEVICE_ATTR(preserves_write_order, bool, NULL);
static ssize_t nullb_device_power_show(struct config_item *item, char *page)
{
@@ -613,6 +614,7 @@ static struct configfs_attribute *nullb_device_attrs[] = {
&nullb_device_attr_no_sched,
&nullb_device_attr_poll_queues,
&nullb_device_attr_power,
+ &nullb_device_attr_preserves_write_order,
&nullb_device_attr_queue_mode,
&nullb_device_attr_rotational,
&nullb_device_attr_shared_tag_bitmap,
@@ -1979,6 +1981,8 @@ static int null_add_dev(struct nullb_device *dev)
if (dev->virt_boundary)
lim.virt_boundary_mask = PAGE_SIZE - 1;
null_config_discard(nullb, &lim);
+ if (dev->preserves_write_order)
+ lim.features |= BLK_FEAT_ORDERED_HWQ;
if (dev->zoned) {
rv = null_init_zoned_dev(dev, &lim);
if (rv)
diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h
index 7bb6128dbaaf..08b732cf853f 100644
--- a/drivers/block/null_blk/null_blk.h
+++ b/drivers/block/null_blk/null_blk.h
@@ -110,6 +110,7 @@ struct nullb_device {
bool shared_tag_bitmap; /* use hostwide shared tags */
bool fua; /* Support FUA */
bool rotational; /* Fake rotational device */
+ bool preserves_write_order;
};
struct nullb {
