1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * 4 * Copyright (C) 2011 Novell Inc. 5 * Copyright (C) 2016 Red Hat, Inc. 6 */ 7 8 struct ovl_config { 9 char *lowerdir; 10 char *upperdir; 11 char *workdir; 12 bool default_permissions; 13 bool redirect_dir; 14 bool redirect_follow; 15 const char *redirect_mode; 16 bool index; 17 bool nfs_export; 18 int xino; 19 bool metacopy; 20 bool override_creds; 21 }; 22 23 struct ovl_sb { 24 struct super_block *sb; 25 dev_t pseudo_dev; 26 /* Unusable (conflicting) uuid */ 27 bool bad_uuid; 28 }; 29 30 struct ovl_layer { 31 struct vfsmount *mnt; 32 /* Trap in ovl inode cache */ 33 struct inode *trap; 34 struct ovl_sb *fs; 35 /* Index of this layer in fs root (upper idx == 0) */ 36 int idx; 37 /* One fsid per unique underlying sb (upper fsid == 0) */ 38 int fsid; 39 }; 40 41 struct ovl_path { 42 struct ovl_layer *layer; 43 struct dentry *dentry; 44 }; 45 46 /* private information held for overlayfs's superblock */ 47 struct ovl_fs { 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; 60 long namelen; 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; 65 bool tmpfile; 66 bool noxattr; 67 /* Did we take the inuse lock? */ 68 bool upperdir_locked; 69 bool workdir_locked; 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; 77 }; 78 79 /* private information held for every overlayfs dentry */ 80 struct ovl_entry { 81 union { 82 struct { 83 unsigned long flags; 84 }; 85 struct rcu_head rcu; 86 }; 87 unsigned numlower; 88 struct ovl_path lowerstack[]; 89 }; 90 91 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 92 OVL_E(struct dentry * dentry)93static inline struct ovl_entry *OVL_E(struct dentry *dentry) 94 { 95 return (struct ovl_entry *) dentry->d_fsdata; 96 } 97 98 struct ovl_inode { 99 union { 100 struct ovl_dir_cache *cache; /* directory */ 101 struct inode *lowerdata; /* regular file */ 102 }; 103 const char *redirect; 104 u64 version; 105 unsigned long flags; 106 struct inode vfs_inode; 107 struct dentry *__upperdentry; 108 struct inode *lower; 109 110 /* synchronize copy up and more */ 111 struct mutex lock; 112 }; 113 OVL_I(struct inode * inode)114static inline struct ovl_inode *OVL_I(struct inode *inode) 115 { 116 return container_of(inode, struct ovl_inode, vfs_inode); 117 } 118 ovl_upperdentry_dereference(struct ovl_inode * oi)119static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) 120 { 121 return READ_ONCE(oi->__upperdentry); 122 } 123