[PATCH] Add block_device_operations.getgeo block device method

HDIO_GETGEO is implemented in most block drivers, and all of them have to
duplicate the code to copy the structure to userspace, as well as getting
the start sector.  This patch moves that to common code [1] and adds a
->getgeo method to fill out the raw kernel hd_geometry structure.  For many
drivers this means ->ioctl can go away now.

[1] the s390 block drivers are odd in this respect.  xpram sets ->start
    to 4 always which seems more than odd, and the dasd driver shifts
    the start offset around, probably because of it's non-standard
    sector size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@suse.de>
Cc: <mike.miller@hp.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 0e97fcb..c05ee8b 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -169,38 +169,26 @@
 	return 0;
 }
 
-/* This ioctl implementation expects userland to have the device node
- * permissions set so that only priviledged users can open an aoe
- * block device directly.
- */
 static int
-aoeblk_ioctl(struct inode *inode, struct file *filp, uint cmd, ulong arg)
+aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
-	struct aoedev *d;
+	struct aoedev *d = bdev->bd_disk->private_data;
 
-	if (!arg)
-		return -EINVAL;
-
-	d = inode->i_bdev->bd_disk->private_data;
 	if ((d->flags & DEVFL_UP) == 0) {
 		printk(KERN_ERR "aoe: aoeblk_ioctl: disk not up\n");
 		return -ENODEV;
 	}
 
-	if (cmd == HDIO_GETGEO) {
-		d->geo.start = get_start_sect(inode->i_bdev);
-		if (!copy_to_user((void __user *) arg, &d->geo, sizeof d->geo))
-			return 0;
-		return -EFAULT;
-	}
-	printk(KERN_INFO "aoe: aoeblk_ioctl: unknown ioctl %d\n", cmd);
-	return -EINVAL;
+	geo->cylinders = d->geo.cylinders;
+	geo->heads = d->geo.heads;
+	geo->sectors = d->geo.sectors;
+	return 0;
 }
 
 static struct block_device_operations aoe_bdops = {
 	.open = aoeblk_open,
 	.release = aoeblk_release,
-	.ioctl = aoeblk_ioctl,
+	.getgeo = aoeblk_getgeo,
 	.owner = THIS_MODULE,
 };