rbd: set snapc->seq only when refreshing header
In rbd_header_add_snap() there is code to set snapc->seq to the
just-added snapshot id. This is the only remnant left of the
use of that field for recording which snapshot an rbd_dev was
associated with. That functionality is no longer supported,
so get rid of that final bit of code.
Doing so means we never actually set snapc->seq any more. On the
server, the snapshot context's sequence value represents the highest
snapshot id ever issued for a particular rbd image. So we'll make
it have that meaning here as well. To do so, set this value
whenever the rbd header is (re-)read. That way it will always be
consistent with the rest of the snapshot context we maintain.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index ac8a83f..c299a55 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -537,6 +537,7 @@
atomic_set(&header->snapc->nref, 1);
header->snap_seq = le64_to_cpu(ondisk->snap_seq);
+ header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
header->snapc->num_snaps = snap_count;
header->total_snaps = snap_count;
@@ -1685,14 +1686,7 @@
kfree(data);
- if (ret < 0)
- return ret;
-
- down_write(&rbd_dev->header_rwsem);
- rbd_dev->header.snapc->seq = new_snapid;
- up_write(&rbd_dev->header_rwsem);
-
- return 0;
+ return ret < 0 ? ret : 0;
bad:
return -ERANGE;
}