3 * Copyright (C) 2011 Novell Inc.
4 * Copyright (C) 2016 Red Hat, Inc.
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.
15 bool default_permissions;
18 const char *redirect_mode;
26 struct super_block *sb;
32 /* Trap in ovl inode cache */
35 /* Index of this layer in fs root (upper idx == 0) */
37 /* One fsid per unique underlying sb (upper fsid == 0) */
42 struct ovl_layer *layer;
43 struct dentry *dentry;
46 /* private information held for overlayfs's superblock */
48 struct vfsmount *upper_mnt;
49 unsigned int numlower;
50 /* Number of unique lower sb that differ from upper sb */
51 unsigned int numlowerfs;
52 struct ovl_layer *lower_layers;
53 struct ovl_sb *lower_fs;
54 /* workbasedir is the path at workdir= mount option */
55 struct dentry *workbasedir;
56 /* workdir is the 'work' directory under workbasedir */
57 struct dentry *workdir;
58 /* index directory listing overlay inodes by origin file handle */
59 struct dentry *indexdir;
61 /* pathnames of lower and upper dirs, for show_options */
62 struct ovl_config config;
63 /* creds of process who forced instantiation of super block */
64 const struct cred *creator_cred;
67 /* Did we take the inuse lock? */
70 /* Traps in ovl inode cache */
71 struct inode *upperdir_trap;
72 struct inode *workbasedir_trap;
73 struct inode *workdir_trap;
74 struct inode *indexdir_trap;
75 /* Inode numbers in all layers do not use the high xino_bits */
76 unsigned int xino_bits;
79 /* private information held for every overlayfs dentry */
88 struct ovl_path lowerstack[];
91 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
93 static inline struct ovl_entry *OVL_E(struct dentry *dentry)
95 return (struct ovl_entry *) dentry->d_fsdata;
100 struct ovl_dir_cache *cache; /* directory */
101 struct inode *lowerdata; /* regular file */
103 const char *redirect;
106 struct inode vfs_inode;
107 struct dentry *__upperdentry;
110 /* synchronize copy up and more */
114 static inline struct ovl_inode *OVL_I(struct inode *inode)
116 return container_of(inode, struct ovl_inode, vfs_inode);
119 static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi)
121 return READ_ONCE(oi->__upperdentry);