Btrfs: incremental send, remove dead code

The logic to detect path loops when attempting to apply a pending
directory rename, introduced in commit
f959492fc15b (Btrfs: send, fix more issues related to directory renames)
is no longer needed, and the respective fstests test case for that commit,
btrfs/045, now passes without this code (as well as all the other test
cases for send/receive).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/send.c

@@ -3067,48 +3067,6 @@ static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
 	return NULL;
 }
 
-static int path_loop(struct send_ctx *sctx, struct fs_path *name,
-		     u64 ino, u64 gen, u64 *ancestor_ino)
-{
-	int ret = 0;
-	u64 parent_inode = 0;
-	u64 parent_gen = 0;
-	u64 start_ino = ino;
-
-	*ancestor_ino = 0;
-	while (ino != BTRFS_FIRST_FREE_OBJECTID) {
-		fs_path_reset(name);
-
-		if (is_waiting_for_rm(sctx, ino))
-			break;
-		if (is_waiting_for_move(sctx, ino)) {
-			if (*ancestor_ino == 0)
-				*ancestor_ino = ino;
-			ret = get_first_ref(sctx->parent_root, ino,
-					    &parent_inode, &parent_gen, name);
-		} else {
-			ret = __get_cur_name_and_parent(sctx, ino, gen,
-							&parent_inode,
-							&parent_gen, name);
-			if (ret > 0) {
-				ret = 0;
-				break;
-			}
-		}
-		if (ret < 0)
-			break;
-		if (parent_inode == start_ino) {
-			ret = 1;
-			if (*ancestor_ino == 0)
-				*ancestor_ino = ino;
-			break;
-		}
-		ino = parent_inode;
-		gen = parent_gen;
-	}
-	return ret;
-}
-
 static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
 {
 	struct fs_path *from_path = NULL;
@@ -3120,7 +3078,6 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
 	struct waiting_dir_move *dm = NULL;
 	u64 rmdir_ino = 0;
 	int ret;
-	u64 ancestor = 0;
 
 	name = fs_path_alloc();
 	from_path = fs_path_alloc();
@@ -3152,22 +3109,6 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
 		goto out;
 
 	sctx->send_progress = sctx->cur_ino + 1;
-	ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor);
-	if (ret) {
-		LIST_HEAD(deleted_refs);
-		ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);
-		ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor,
-					   &pm->update_refs, &deleted_refs,
-					   pm->is_orphan);
-		if (ret < 0)
-			goto out;
-		if (rmdir_ino) {
-			dm = get_waiting_dir_move(sctx, pm->ino);
-			ASSERT(dm);
-			dm->rmdir_ino = rmdir_ino;
-		}
-		goto out;
-	}
 	fs_path_reset(name);
 	to_path = name;
 	name = NULL;