rbd: expose the correct size of the device in sysfs

If an image was mapped to a snapshot, the size of the head version
would be shown. Protect capacity with header_rwsem, since it may
change.

Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This commit is contained in:
Josh Durgin 2011-12-05 10:35:04 -08:00 committed by Sage Weil
parent 474ef7ce83
commit a51aa0c042

View file

@ -1724,6 +1724,8 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev)
if (ret < 0)
return ret;
down_write(&rbd_dev->header_rwsem);
/* resized? */
if (rbd_dev->snap_id == CEPH_NOSNAP) {
sector_t size = (sector_t) h.image_size / SECTOR_SIZE;
@ -1732,8 +1734,6 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev)
set_capacity(rbd_dev->disk, size);
}
down_write(&rbd_dev->header_rwsem);
snap_seq = rbd_dev->header.snapc->seq;
if (rbd_dev->header.total_snaps &&
rbd_dev->header.snapc->snaps[0] == snap_seq)
@ -1853,8 +1853,13 @@ static ssize_t rbd_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
sector_t size;
return sprintf(buf, "%llu\n", (unsigned long long)rbd_dev->header.image_size);
down_read(&rbd_dev->header_rwsem);
size = get_capacity(rbd_dev->disk);
up_read(&rbd_dev->header_rwsem);
return sprintf(buf, "%llu\n", (unsigned long long) size * SECTOR_SIZE);
}
static ssize_t rbd_major_show(struct device *dev,