[PATCH 2/2] Add serial number support for virtio_blk, V4

[john cooper <john.cooper@redhat.com>]

virtio_blk-serial-4.patch



 drivers/block/virtio_blk.c |   41 ++++++++++++++++++++++++++++++++++++++---
 include/linux/virtio_blk.h |    7 +++++++
 2 files changed, 45 insertions(+), 3 deletions(-)
=================================================================
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -146,12 +146,46 @@ static void do_virtblk_request(struct re
 		vblk->vq->vq_ops->kick(vblk->vq);
 }
 
+/* return ATA identify data
+ */
+static int virtblk_identify(struct gendisk *disk, void *argp)
+{
+	struct virtio_blk *vblk = disk->private_data;
+	u16 *id;
+	int err = -ENOMEM;
+
+	id = kmalloc(VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
+	if (!id)
+		goto out;
+
+	err = virtio_config_buf(vblk->vdev, VIRTIO_BLK_F_IDENTIFY,
+		offsetof(struct virtio_blk_config, identify), id,
+		VIRTIO_BLK_ID_BYTES);
+
+	if (err)
+		goto out_kfree;
+
+	if (copy_to_user(argp, id, VIRTIO_BLK_ID_BYTES))
+		err = -EFAULT;
+
+out_kfree:
+	kfree(id);
+out:
+	return err;
+}
+
 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
 			 unsigned cmd, unsigned long data)
 {
-	return scsi_cmd_ioctl(bdev->bd_disk->queue,
-			      bdev->bd_disk, mode, cmd,
-			      (void __user *)data);
+	struct gendisk *disk = bdev->bd_disk;
+	void __user *argp = (void __user *)data;
+
+	switch (cmd) {
+	case HDIO_GET_IDENTITY:
+		return virtblk_identify(disk, argp);
+	default:
+		return scsi_cmd_ioctl(disk->queue, disk, mode, cmd, argp);
+	}
 }
 
 /* We provide getgeo only to please some old bootloader/partitioning tools */
@@ -356,6 +390,7 @@ static struct virtio_device_id id_table[
 static unsigned int features[] = {
 	VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
 	VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
+	VIRTIO_BLK_F_IDENTIFY
 };
 
 static struct virtio_driver virtio_blk = {
=================================================================
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -15,7 +15,13 @@
 #define VIRTIO_BLK_F_GEOMETRY	4	/* Legacy geometry available  */
 #define VIRTIO_BLK_F_RO		5	/* Disk is read-only */
 #define VIRTIO_BLK_F_BLK_SIZE	6	/* Block size of disk is available*/
+#define VIRTIO_BLK_F_IDENTIFY	8	/* ATA IDENTIFY supported */
 
+#define VIRTIO_BLK_ID_LEN 256
+#define VIRTIO_BLK_ID_BYTES (VIRTIO_BLK_ID_LEN * sizeof (u16))
+
+/* mapped into pci i/o region 0
+ */
 struct virtio_blk_config
 {
 	/* The capacity (in 512-byte sectors). */
@@ -32,6 +38,7 @@ struct virtio_blk_config
 	} geometry;
 	/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
 	__u32 blk_size;
+	__u16 identify[VIRTIO_BLK_ID_LEN];
 } __attribute__((packed));
 
 /* These two define direction. */
-- 
john.cooper@redhat.com