[PATCH] virtio_pmem: Check device status before requesting flush

From: Philip Chen
Date: Wed Aug 14 2024 - 20:58:49 EST


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.

Signed-off-by: Philip Chen <philipchen@xxxxxxxxxxxx>
---
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 35c8fbbba10e..3b4d07aa8447 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 send the request to the device if the device is not
+ * acticated.
+ */
+ 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)
--
2.46.0.76.ge559c4bf1a-goog