btree: export btree_get_prev() so modules can use btree_for_each

The btree_for_each API is implemented with macros that internally call
btree_get_prev(), so if btree_get_prev() isn't exported then modules fail
to link if they try to use one of the btree_for_each macros.  Since the
rest of the btree API is exported, we should keep things orthogonal and
make this work too.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Steve Hodgson <steve@purestorage.com>
Acked-by: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/btree.c b/lib/btree.c
index 2a34392bcecc..e5ec1e9c1aa5 100644
--- a/lib/btree.c
+++ b/lib/btree.c
@@ -357,6 +357,7 @@ miss:
         }
         return NULL;
 }
+EXPORT_SYMBOL_GPL(btree_get_prev);
 
 static int getpos(struct btree_geo *geo, unsigned long *node,
                 unsigned long *key)