1 files changed, 106 insertions, 18 deletions

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index c10e4c70f02d..20d3300bd268 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -3521,7 +3521,40 @@ out:
 }
 
 /*
- * Check if ino ino1 is an ancestor of inode ino2 in the given root.
+ * Check if inode ino2, or any of its ancestors, is inode ino1.
+ * Return 1 if true, 0 if false and < 0 on error.
+ */
+static int check_ino_in_path(struct btrfs_root *root,
+			     const u64 ino1,
+			     const u64 ino1_gen,
+			     const u64 ino2,
+			     const u64 ino2_gen,
+			     struct fs_path *fs_path)
+{
+	u64 ino = ino2;
+
+	if (ino1 == ino2)
+		return ino1_gen == ino2_gen;
+
+	while (ino > BTRFS_FIRST_FREE_OBJECTID) {
+		u64 parent;
+		u64 parent_gen;
+		int ret;
+
+		fs_path_reset(fs_path);
+		ret = get_first_ref(root, ino, &parent, &parent_gen, fs_path);
+		if (ret < 0)
+			return ret;
+		if (parent == ino1)
+			return parent_gen == ino1_gen;
+		ino = parent;
+	}
+	return 0;
+}
+
+/*
+ * Check if ino ino1 is an ancestor of inode ino2 in the given root for any
+ * possible path (in case ino2 is not a directory and has multiple hard links).
  * Return 1 if true, 0 if false and < 0 on error.
  */
 static int is_ancestor(struct btrfs_root *root,
@@ -3530,36 +3563,91 @@ static int is_ancestor(struct btrfs_root *root,
 		       const u64 ino2,
 		       struct fs_path *fs_path)
 {
-	u64 ino = ino2;
-	bool free_path = false;
+	bool free_fs_path = false;
 	int ret = 0;
+	struct btrfs_path *path = NULL;
+	struct btrfs_key key;
 
 	if (!fs_path) {
 		fs_path = fs_path_alloc();
 		if (!fs_path)
 			return -ENOMEM;
-		free_path = true;
+		free_fs_path = true;
 	}
 
-	while (ino > BTRFS_FIRST_FREE_OBJECTID) {
-		u64 parent;
-		u64 parent_gen;
+	path = alloc_path_for_send();
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
-		fs_path_reset(fs_path);
-		ret = get_first_ref(root, ino, &parent, &parent_gen, fs_path);
-		if (ret < 0) {
-			if (ret == -ENOENT && ino == ino2)
-				ret = 0;
-			goto out;
+	key.objectid = ino2;
+	key.type = BTRFS_INODE_REF_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	while (true) {
+		struct extent_buffer *leaf = path->nodes[0];
+		int slot = path->slots[0];
+		u32 cur_offset = 0;
+		u32 item_size;
+
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0)
+				goto out;
+			if (ret > 0)
+				break;
+			continue;
 		}
-		if (parent == ino1) {
-			ret = parent_gen == ino1_gen ? 1 : 0;
-			goto out;
+
+		btrfs_item_key_to_cpu(leaf, &key, slot);
+		if (key.objectid != ino2)
+			break;
+		if (key.type != BTRFS_INODE_REF_KEY &&
+		    key.type != BTRFS_INODE_EXTREF_KEY)
+			break;
+
+		item_size = btrfs_item_size_nr(leaf, slot);
+		while (cur_offset < item_size) {
+			u64 parent;
+			u64 parent_gen;
+
+			if (key.type == BTRFS_INODE_EXTREF_KEY) {
+				unsigned long ptr;
+				struct btrfs_inode_extref *extref;
+
+				ptr = btrfs_item_ptr_offset(leaf, slot);
+				extref = (struct btrfs_inode_extref *)
+					(ptr + cur_offset);
+				parent = btrfs_inode_extref_parent(leaf,
+								   extref);
+				cur_offset += sizeof(*extref);
+				cur_offset += btrfs_inode_extref_name_len(leaf,
+								  extref);
+			} else {
+				parent = key.offset;
+				cur_offset = item_size;
+			}
+
+			ret = get_inode_info(root, parent, NULL, &parent_gen,
+					     NULL, NULL, NULL, NULL);
+			if (ret < 0)
+				goto out;
+			ret = check_ino_in_path(root, ino1, ino1_gen,
+						parent, parent_gen, fs_path);
+			if (ret)
+				goto out;
 		}
-		ino = parent;
+		path->slots[0]++;
 	}
+	ret = 0;
  out:
-	if (free_path)
+	btrfs_free_path(path);
+	if (free_fs_path)
 		fs_path_free(fs_path);
 	return ret;
 }