rbd: update mapping size only on refresh

There is no sense in trying to update the mapping size before it's even
been set.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>

1 files changed, 7 insertions, 12 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index c4064c53b9c9..92a9ce0a9e85 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -971,12 +971,6 @@ static int rbd_header_from_disk(struct rbd_device *rbd_dev,
         header->snap_names = snap_names;
         header->snap_sizes = snap_sizes;
 
-        /* Make sure mapping size is consistent with header info */
-
-        if (rbd_dev->spec->snap_id == CEPH_NOSNAP || first_time)
-                if (rbd_dev->mapping.size != header->image_size)
-                        rbd_dev->mapping.size = header->image_size;
-
         return 0;
 out_2big:
         ret = -EIO;
@@ -3522,9 +3516,14 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
         if (ret)
                 return ret;
 
-        /* If it's a mapped snapshot, validate its EXISTS flag */
+        if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
+                if (rbd_dev->mapping.size != rbd_dev->header.image_size)
+                        rbd_dev->mapping.size = rbd_dev->header.image_size;
+        } else {
+                /* validate mapped snapshot's EXISTS flag */
+                rbd_exists_validate(rbd_dev);
+        }
 
-        rbd_exists_validate(rbd_dev);
         up_write(&rbd_dev->header_rwsem);
 
         if (mapping_size != rbd_dev->mapping.size) {
@@ -4507,10 +4506,6 @@ static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
                                         "is EXPERIMENTAL!");
         }
 
-        if (rbd_dev->spec->snap_id == CEPH_NOSNAP)
-                if (rbd_dev->mapping.size != rbd_dev->header.image_size)
-                        rbd_dev->mapping.size = rbd_dev->header.image_size;
-
         ret = rbd_dev_v2_snap_context(rbd_dev);
         dout("rbd_dev_v2_snap_context returned %d\n", ret);