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 }; 21 22 struct ovl_sb { 23 struct super_block *sb; 24 dev_t pseudo_dev; 25 /* Unusable (conflicting) uuid */ 26 bool bad_uuid; 27 /* Used as a lower layer (but maybe also as upper) */ 28 bool is_lower; 29 }; 30 31 struct ovl_layer { 32 struct vfsmount *mnt; 33 /* Trap in ovl inode cache */ 34 struct inode *trap; 35 struct ovl_sb *fs; 36 /* Index of this layer in fs root (upper idx == 0) */ 37 int idx; 38 /* One fsid per unique underlying sb (upper fsid == 0) */ 39 int fsid; 40 }; 41 42 struct ovl_path { 43 const struct ovl_layer *layer; 44 struct dentry *dentry; 45 }; 46 47 /* private information held for overlayfs's superblock */ 48 struct ovl_fs { 49 struct vfsmount *upper_mnt; 50 unsigned int numlayer; 51 /* Number of unique fs among layers including upper fs */ 52 unsigned int numfs; 53 const struct ovl_layer *layers; 54 struct ovl_sb *fs; 55 /* workbasedir is the path at workdir= mount option */ 56 struct dentry *workbasedir; 57 /* workdir is the 'work' directory under workbasedir */ 58 struct dentry *workdir; 59 /* index directory listing overlay inodes by origin file handle */ 60 struct dentry *indexdir; 61 long namelen; 62 /* pathnames of lower and upper dirs, for show_options */ 63 struct ovl_config config; 64 /* creds of process who forced instantiation of super block */ 65 const struct cred *creator_cred; 66 bool tmpfile; 67 bool noxattr; 68 /* Did we take the inuse lock? */ 69 bool upperdir_locked; 70 bool workdir_locked; 71 /* Traps in ovl inode cache */ 72 struct inode *upperdir_trap; 73 struct inode *workbasedir_trap; 74 struct inode *workdir_trap; 75 struct inode *indexdir_trap; 76 /* -1: disabled, 0: same fs, 1..32: number of unused ino bits */ 77 int xino_mode; 78 }; 79 80 static inline struct ovl_fs *OVL_FS(struct super_block *sb) 81 { 82 return (struct ovl_fs *)sb->s_fs_info; 83 } 84 85 /* private information held for every overlayfs dentry */ 86 struct ovl_entry { 87 union { 88 struct { 89 unsigned long flags; 90 }; 91 struct rcu_head rcu; 92 }; 93 unsigned numlower; 94 struct ovl_path lowerstack[]; 95 }; 96 97 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 98 99 static inline struct ovl_entry *OVL_E(struct dentry *dentry) 100 { 101 return (struct ovl_entry *) dentry->d_fsdata; 102 } 103 104 struct ovl_inode { 105 union { 106 struct ovl_dir_cache *cache; /* directory */ 107 struct inode *lowerdata; /* regular file */ 108 }; 109 const char *redirect; 110 u64 version; 111 unsigned long flags; 112 struct inode vfs_inode; 113 struct dentry *__upperdentry; 114 struct inode *lower; 115 116 /* synchronize copy up and more */ 117 struct mutex lock; 118 }; 119 120 static inline struct ovl_inode *OVL_I(struct inode *inode) 121 { 122 return container_of(inode, struct ovl_inode, vfs_inode); 123 } 124 125 static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) 126 { 127 return READ_ONCE(oi->__upperdentry); 128 } 129