rbd: only reset capacity when pointing to head

Snapshots cannot be resized, and the new capacity of head should not
be reflected by the snapshot.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 730d0ce505e1..f171cebabda9 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1725,7 +1725,12 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev)
                 return ret;
 
         /* resized? */
-        set_capacity(rbd_dev->disk, h.image_size / SECTOR_SIZE);
+        if (rbd_dev->snap_id == CEPH_NOSNAP) {
+                sector_t size = (sector_t) h.image_size / SECTOR_SIZE;
+
+                dout("setting size to %llu sectors", (unsigned long long) size);
+                set_capacity(rbd_dev->disk, size);
+        }
 
         down_write(&rbd_dev->header_rwsem);