1 /* 2 * 3 * Copyright (C) 2011 Novell Inc. 4 * Copyright (C) 2016 Red Hat, Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 */ 10 11 struct ovl_config { 12 char *lowerdir; 13 char *upperdir; 14 char *workdir; 15 bool default_permissions; 16 bool redirect_dir; 17 }; 18 19 /* private information held for overlayfs's superblock */ 20 struct ovl_fs { 21 struct vfsmount *upper_mnt; 22 unsigned numlower; 23 struct vfsmount **lower_mnt; 24 struct dentry *workdir; 25 long namelen; 26 /* pathnames of lower and upper dirs, for show_options */ 27 struct ovl_config config; 28 /* creds of process who forced instantiation of super block */ 29 const struct cred *creator_cred; 30 bool tmpfile; 31 wait_queue_head_t copyup_wq; 32 /* sb common to all layers */ 33 struct super_block *same_sb; 34 }; 35 36 /* private information held for every overlayfs dentry */ 37 struct ovl_entry { 38 struct dentry *__upperdentry; 39 struct ovl_dir_cache *cache; 40 union { 41 struct { 42 u64 version; 43 const char *redirect; 44 bool opaque; 45 bool copying; 46 }; 47 struct rcu_head rcu; 48 }; 49 unsigned numlower; 50 struct path lowerstack[]; 51 }; 52 53 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 54 55 static inline struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe) 56 { 57 return lockless_dereference(oe->__upperdentry); 58 } 59