block/qcow2: Make get_refcount() global

Reading the refcount of a cluster is an operation which can be useful in
all of the qcow2 code, so make that function globally available.

While touching this function, amend the comment describing the "addend"
parameter: It is (no longer, if it ever was) necessary to have it set to
-1 or 1; any value is fine.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Message-id: 1414404776-4919-6-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block/qcow2.h b/block/qcow2.h
index 21ac8ce..6e39a1b 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -487,6 +487,8 @@ void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 int qcow2_refcount_init(BlockDriverState *bs);
 void qcow2_refcount_close(BlockDriverState *bs);
 
+int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index);
+
 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
                                   int addend, enum qcow2_discard_type type);