[PATCH AUTOSEL 6.1 34/42] virtio_pmem: Check device status before requesting flush

Sasha Levin
2024-10-04T18:28:19Z

From: Philip Chen <philipchen@chromium.org>

[ Upstream commit e25fbcd97cf52c3c9824d44b5c56c19673c3dd50 ]

If a pmem device is in a bad status, the driver side could wait for
host ack forever in virtio_pmem_flush(), causing the system to hang.

So add a status check in the beginning of virtio_pmem_flush() to return
early if the device is not activated.

Signed-off-by: Philip Chen <philipchen@chromium.org>
Message-Id: <20240826215313.2673566-1-philipchen@chromium.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvdimm/nd_virtio.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c
index c6a648fd8744a..a78e17a43a9d2 100644
--- a/drivers/nvdimm/nd_virtio.c
+++ b/drivers/nvdimm/nd_virtio.c
@@ -44,6 +44,15 @@ static int virtio_pmem_flush(struct nd_region *nd_region)
unsigned long flags;
int err, err1;

+ /*
+ * Don't bother to submit the request to the device if the device is
+ * not activated.
+ */
+ if (vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_NEEDS_RESET) {
+ dev_info(&vdev->dev, "virtio pmem device needs a reset\n");
+ return -EIO;
+ }
+
might_sleep();
req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
if (!req_data)
--
2.43.0