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>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index f171ceb..9c3a1db 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1724,6 +1724,8 @@
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 @@
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 @@
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,