1 files changed, 16 insertions, 1 deletions
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 08354394b1bb..fec77b30a249 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -17,6 +17,20 @@ struct inode_fs_paths {
 	struct btrfs_data_container	*fspath;
 };
 
+struct btrfs_backref_shared_cache_entry {
+	u64 bytenr;
+	u64 gen;
+	bool is_shared;
+};
+
+struct btrfs_backref_shared_cache {
+	/*
+	 * A path from a root to a leaf that has a file extent item pointing to
+	 * a given data extent should never exceed the maximum b+tree height.
+	 */
+	struct btrfs_backref_shared_cache_entry entries[BTRFS_MAX_LEVEL];
+};
+
 typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
 		void *ctx);
 
@@ -63,7 +77,8 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
 			  struct btrfs_inode_extref **ret_extref,
 			  u64 *found_off);
 int btrfs_is_data_extent_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
-				struct ulist *roots, struct ulist *tmp);
+				struct ulist *roots, struct ulist *tmp,
+				struct btrfs_backref_shared_cache *cache);
 
 int __init btrfs_prelim_ref_init(void);
 void __cold btrfs_prelim_ref_exit(void);