bcachefs: Set lost+found mode to 0700

For security and conformance with other filesystems, the lost+found
directory should not be world or group accessible.
Signed-off-by: Justin Husted <sigstop@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/fsck.c

@@ -797,7 +797,7 @@ static int check_lostfound(struct bch_fs *c,
 		bch2_create_trans(&trans,
 				  BCACHEFS_ROOT_INO, root_inode,
 				  lostfound_inode, &lostfound,
-				  0, 0, S_IFDIR|0755, 0, NULL, NULL));
+				  0, 0, S_IFDIR|0700, 0, NULL, NULL));
 	if (ret)
 		bch_err(c, "error creating lost+found: %i", ret);
 

fs/bcachefs/recovery.c

@@ -1013,7 +1013,7 @@ int bch2_fs_initialize(struct bch_fs *c)
 		bch2_create_trans(&trans, BCACHEFS_ROOT_INO,
 				  &root_inode, &lostfound_inode,
 				  &lostfound,
-				  0, 0, S_IFDIR|0755, 0,
+				  0, 0, S_IFDIR|0700, 0,
 				  NULL, NULL));
 	if (ret)
 		goto err;