Commit 10805eb5 authored by Dmitry Fomichev's avatar Dmitry Fomichev Committed by Michael S. Tsirkin
Browse files

virtio-blk: fix ZBD probe in kernels without ZBD support 



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: 95bfec41 ("virtio-blk: add support for zoned block devices")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Message-Id: <20230330214953.1088216-3-dmitry.fomichev@wdc.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent f1ba4e67

drivers/block/virtio_blk.c

+17 −16
Original line number Diff line number Diff line
@@ -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)

{

	u8 model;



	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;

	}



static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev)

{

	return false;

	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 = {