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 Cc: Christoph Hellwig Signed-off-by: Bart Van Assche --- 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 {