When the kernel is built without support for zoned block devices,
virtio-blk probe needs to error out any host-managed device scans
to prevent such devices from appearing in the system as non-zoned.
The current virtio-blk code simply bypasses all ZBD checks if
CONFIG_BLK_DEV_ZONED is not defined and this leads to host-managed
block devices being presented as non-zoned in the OS. This is one of
the main problems this patch series is aimed to fix.
In this patch, make VIRTIO_BLK_F_ZONED feature defined even when
CONFIG_BLK_DEV_ZONED is not. This change makes the code compliant with
the voted revision of virtio-blk ZBD spec. Modify the probe code to
look at the situation when VIRTIO_BLK_F_ZONED is negotiated in a kernel
that is built without ZBD support. In this case, the code checks
the zoned model of the device and fails the probe is the device
is host-managed.
The patch also adds the comment to clarify that the call to perform
the zoned device probe is correctly placed after virtio_device ready().
Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@xxxxxxx>
Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
---
drivers/block/virtio_blk.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 4f0dbbb3d4a5..2b918e28acaa 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -866,16 +866,12 @@ static int virtblk_probe_zoned_device(struct virtio_device *vdev,
return ret;
}
-static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev)
-{
- return virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED);
-}
-
#else
/*
* Zoned block device support is not configured in this kernel.
- * We only need to define a few symbols to avoid compilation errors.
+ * Host-managed zoned devices can't be supported, but others are
+ * good to go as regular block devices.
*/
#define virtblk_report_zones NULL
@@ -886,12 +882,16 @@ static inline void virtblk_revalidate_zones(struct virtio_blk *vblk)
static inline int virtblk_probe_zoned_device(struct virtio_device *vdev,
struct virtio_blk *vblk, struct request_queue *q)
{
- return -EOPNOTSUPP;
-}
+ u8 model;
-static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev)
-{
- return false;
+ virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model);
+ if (model == VIRTIO_BLK_Z_HM) {
+ dev_err(&vdev->dev,
+ "virtio_blk: zoned devices are not supported");
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
}
#endif /* CONFIG_BLK_DEV_ZONED */
@@ -1577,7 +1577,11 @@ static int virtblk_probe(struct virtio_device *vdev)
virtblk_update_capacity(vblk, false);
virtio_device_ready(vdev);
- if (virtblk_has_zoned_feature(vdev)) {
+ /*
+ * All steps that follow use the VQs therefore they need to be
+ * placed after the virtio_device_ready() call above.
+ */
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
err = virtblk_probe_zoned_device(vdev, vblk, q);
if (err)
goto out_cleanup_disk;
@@ -1683,10 +1687,7 @@ static unsigned int features[] = {
VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
- VIRTIO_BLK_F_SECURE_ERASE,
-#ifdef CONFIG_BLK_DEV_ZONED
- VIRTIO_BLK_F_ZONED,
-#endif /* CONFIG_BLK_DEV_ZONED */
+ VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED,
};
static struct virtio_driver virtio_blk = {
--
2.34.1
