diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index dae9fba..828f3a2 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -64,4 +64,5 @@
 int btrfs_read_buffer(struct extent_buffer *buf);
 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
 void btrfs_csum_final(u32 crc, char *result);
+void btrfs_throttle(struct btrfs_root *root);
 #endif