xen/blkfront: Add the CDROM_GET_CAPABILITY ioctl to blkfront.

From: Christian Limpach <[email protected]>

Return 0 instead of -EINVAL if the blkfront device is a cdrom, i.e. had the VDISK_CDROM attribute. This allows udev's cdrom_id to correctly detect the device as a cdrom device.

[ Add blkif_ioctl, and CDROMMULTISESSION ]

[ linux-2.6.18-xen changeset d2bd9af846b5 ]

---
drivers/block/xen-blkfront.c | 36 ++++++++++++++++++++++++++++++++++++

1 file changed, 36 insertions(+)

===================================================================

@@ -38,6 +38,7 @@

#include <linux/interrupt.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
+#include <linux/cdrom.h>
#include <linux/module.h>

#include <xen/xenbus.h>
@@ -150,6 +151,40 @@

	hg->cylinders = cylinders;
	if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect)
		hg->cylinders = 0xffff;

+ return 0;
+}
+
+int blkif_ioctl(struct inode *inode, struct file *filep,
+ unsigned command, unsigned long argument)
+{
+ struct blkfront_info *info =
+ inode->i_bdev->bd_disk->private_data;
+ int i;
+
+ dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n",
+ command, (long)argument);
+
+ switch (command) {
+ case CDROMMULTISESSION:
+ dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n");
+ for (i = 0; i < sizeof(struct cdrom_multisession); i++)
+ if (put_user(0, (char __user *)(argument + i)))
+ return -EFAULT;
+ return 0;
+
+ case CDROM_GET_CAPABILITY: {
+ struct gendisk *gd = info->gd;
+ if (gd->flags & GENHD_FL_CD)
+ return 0;
+ return -EINVAL;
+ }
+
+ default:
+ /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n",
+ command);*/
+ return -EINVAL; /* same return as native Linux */
+ }
+

	return 0;
}

@@ -974,6 +1009,7 @@
.open = blkif_open,
.release = blkif_release,
.getgeo = blkif_getgeo,
+ .ioctl = blkif_ioctl,
};