[PATCH V3 2/2] virtio_pmem: set device ready in probe()

From: Jason Wang
Date: Tue Jun 28 2022 - 04:35:00 EST


The NVDIMM region could be available before the virtio_device_ready()
that is called by virtio_dev_probe(). This means the driver tries to
use device before DRIVER_OK which violates the spec, fixing this by
set device ready before the nvdimm_pmem_region_create().

Note that this means the virtio_pmem_host_ack() could be triggered
before the creation of the nd region, this is safe since the pmem_lock
has been initialized and whether or not any available buffer is added
before is validated by virtio_pmem_host_ack().

Fixes 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver")
Acked-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
Changes since V2:
- Tweak the change log
Changes since v1:
- Remove some comments per Dan
---
drivers/nvdimm/virtio_pmem.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c
index 48f8327d0431..20da455d2ef6 100644
--- a/drivers/nvdimm/virtio_pmem.c
+++ b/drivers/nvdimm/virtio_pmem.c
@@ -84,6 +84,12 @@ static int virtio_pmem_probe(struct virtio_device *vdev)
ndr_desc.provider_data = vdev;
set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
+ /*
+ * The NVDIMM region could be available before the
+ * virtio_device_ready() that is called by
+ * virtio_dev_probe(), so we set device ready here.
+ */
+ virtio_device_ready(vdev);
nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
if (!nd_region) {
dev_err(&vdev->dev, "failed to create nvdimm region\n");
@@ -92,6 +98,7 @@ static int virtio_pmem_probe(struct virtio_device *vdev)
}
return 0;
out_nd:
+ virtio_reset_device(vdev);
nvdimm_bus_unregister(vpmem->nvdimm_bus);
out_vq:
vdev->config->del_vqs(vdev);
--
2.25.1