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Merge branch 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus 

* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio_blk: Remove VBID ioctl
  virtio_blk: Add 'serial' attribute to virtio-blk devices (v2)
  virtio_blk: support barriers without FLUSH feature
This commit is contained in:
Linus Torvalds 2010-08-05 13:49:37 -07:00
parent db7a1535d2 6c99a8528f
commit 552c7dbb34
1 changed files with 51 additions and 13 deletions
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64
drivers/block/virtio_blk.c
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@ -225,16 +225,6 @@ static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
struct gendisk *disk = bdev->bd_disk;
struct virtio_blk *vblk = disk->private_data;
if (cmd == 0x56424944) { /* 'VBID' */
void __user *usr_data = (void __user *)data;
char id_str[VIRTIO_BLK_ID_BYTES];
int err;
err = virtblk_get_id(disk, id_str);
if (!err && copy_to_user(usr_data, id_str, VIRTIO_BLK_ID_BYTES))
err = -EFAULT;
return err;
}
/*
* Only allow the generic SCSI ioctls if the host can support it.
*/
@ -281,6 +271,27 @@ static int index_to_minor(int index)
return index << PART_BITS;
}
static ssize_t virtblk_serial_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gendisk *disk = dev_to_disk(dev);
int err;
/* sysfs gives us a PAGE_SIZE buffer */
BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
buf[VIRTIO_BLK_ID_BYTES] = '\0';
err = virtblk_get_id(disk, buf);
if (!err)
return strlen(buf);
if (err == -EIO) /* Unsupported? Make it empty. */
return 0;
return err;
}
DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
static int __devinit virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
@ -366,12 +377,32 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
/* If barriers are supported, tell block layer that queue is ordered */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) {
/*
* If the FLUSH feature is supported we do have support for
* flushing a volatile write cache on the host. Use that
* to implement write barrier support.
*/
blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH,
virtblk_prepare_flush);
else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER))
} else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) {
/*
* If the BARRIER feature is supported the host expects us
* to order request by tags. This implies there is not
* volatile write cache on the host, and that the host
* never re-orders outstanding I/O. This feature is not
* useful for real life scenarious and deprecated.
*/
blk_queue_ordered(q, QUEUE_ORDERED_TAG, NULL);
} else {
/*
* If the FLUSH feature is not supported we must assume that
* the host does not perform any kind of volatile write
* caching. We still need to drain the queue to provider
* proper barrier semantics.
*/
blk_queue_ordered(q, QUEUE_ORDERED_DRAIN, NULL);
}
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
@ -445,8 +476,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
add_disk(vblk->disk);
err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
if (err)
goto out_del_disk;
return 0;
out_del_disk:
del_gendisk(vblk->disk);
blk_cleanup_queue(vblk->disk->queue);
out_put_disk:
put_disk(vblk->disk);
out_mempool: