1d2912cb1SThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-only */ 2bbb1e54dSMiklos Szeredi /* 3bbb1e54dSMiklos Szeredi * 4bbb1e54dSMiklos Szeredi * Copyright (C) 2011 Novell Inc. 5bbb1e54dSMiklos Szeredi * Copyright (C) 2016 Red Hat, Inc. 6bbb1e54dSMiklos Szeredi */ 7bbb1e54dSMiklos Szeredi 8bbb1e54dSMiklos Szeredi struct ovl_config { 9bbb1e54dSMiklos Szeredi char *lowerdir; 10bbb1e54dSMiklos Szeredi char *upperdir; 11bbb1e54dSMiklos Szeredi char *workdir; 12bbb1e54dSMiklos Szeredi bool default_permissions; 13a6c60655SMiklos Szeredi bool redirect_dir; 14438c84c2SMiklos Szeredi bool redirect_follow; 15438c84c2SMiklos Szeredi const char *redirect_mode; 1602bcd157SAmir Goldstein bool index; 175830fb6bSPavel Tikhomirov bool uuid; 18f168f109SAmir Goldstein bool nfs_export; 19795939a9SAmir Goldstein int xino; 20d5791044SVivek Goyal bool metacopy; 212d2f2d73SMiklos Szeredi bool userxattr; 22c86243b0SVivek Goyal bool ovl_volatile; 23bbb1e54dSMiklos Szeredi }; 24bbb1e54dSMiklos Szeredi 255148626bSAmir Goldstein struct ovl_sb { 265148626bSAmir Goldstein struct super_block *sb; 275148626bSAmir Goldstein dev_t pseudo_dev; 287e63c87fSAmir Goldstein /* Unusable (conflicting) uuid */ 297e63c87fSAmir Goldstein bool bad_uuid; 301b81ddddSAmir Goldstein /* Used as a lower layer (but maybe also as upper) */ 311b81ddddSAmir Goldstein bool is_lower; 325148626bSAmir Goldstein }; 335148626bSAmir Goldstein 34b9343632SChandan Rajendra struct ovl_layer { 35b9343632SChandan Rajendra struct vfsmount *mnt; 36146d62e5SAmir Goldstein /* Trap in ovl inode cache */ 37146d62e5SAmir Goldstein struct inode *trap; 385148626bSAmir Goldstein struct ovl_sb *fs; 395148626bSAmir Goldstein /* Index of this layer in fs root (upper idx == 0) */ 40d583ed7dSAmir Goldstein int idx; 415148626bSAmir Goldstein /* One fsid per unique underlying sb (upper fsid == 0) */ 425148626bSAmir Goldstein int fsid; 43b9343632SChandan Rajendra }; 44b9343632SChandan Rajendra 45b9343632SChandan Rajendra struct ovl_path { 4613464165SMiklos Szeredi const struct ovl_layer *layer; 47b9343632SChandan Rajendra struct dentry *dentry; 48b9343632SChandan Rajendra }; 49b9343632SChandan Rajendra 500af950f5SAmir Goldstein struct ovl_entry { 510af950f5SAmir Goldstein unsigned int __numlower; 520af950f5SAmir Goldstein struct ovl_path __lowerstack[]; 530af950f5SAmir Goldstein }; 540af950f5SAmir Goldstein 55bbb1e54dSMiklos Szeredi /* private information held for overlayfs's superblock */ 56bbb1e54dSMiklos Szeredi struct ovl_fs { 5794375f9dSAmir Goldstein unsigned int numlayer; 5807f1e596SAmir Goldstein /* Number of unique fs among layers including upper fs */ 5907f1e596SAmir Goldstein unsigned int numfs; 6013464165SMiklos Szeredi const struct ovl_layer *layers; 6107f1e596SAmir Goldstein struct ovl_sb *fs; 622cac0c00SAmir Goldstein /* workbasedir is the path at workdir= mount option */ 632cac0c00SAmir Goldstein struct dentry *workbasedir; 642cac0c00SAmir Goldstein /* workdir is the 'work' directory under workbasedir */ 65bbb1e54dSMiklos Szeredi struct dentry *workdir; 6602bcd157SAmir Goldstein /* index directory listing overlay inodes by origin file handle */ 6702bcd157SAmir Goldstein struct dentry *indexdir; 686b2d5fe4SMiklos Szeredi long namelen; 69bbb1e54dSMiklos Szeredi /* pathnames of lower and upper dirs, for show_options */ 70bbb1e54dSMiklos Szeredi struct ovl_config config; 71bbb1e54dSMiklos Szeredi /* creds of process who forced instantiation of super block */ 72bbb1e54dSMiklos Szeredi const struct cred *creator_cred; 73e7f52429SAmir Goldstein bool tmpfile; 7482b749b2SAmir Goldstein bool noxattr; 7585fdee1eSAmir Goldstein /* Did we take the inuse lock? */ 7685fdee1eSAmir Goldstein bool upperdir_locked; 7785fdee1eSAmir Goldstein bool workdir_locked; 78c21c839bSChengguang Xu bool share_whiteout; 79146d62e5SAmir Goldstein /* Traps in ovl inode cache */ 800be0bfd2SAmir Goldstein struct inode *workbasedir_trap; 81146d62e5SAmir Goldstein struct inode *workdir_trap; 82146d62e5SAmir Goldstein struct inode *indexdir_trap; 830f831ec8SAmir Goldstein /* -1: disabled, 0: same fs, 1..32: number of unused ino bits */ 840f831ec8SAmir Goldstein int xino_mode; 854d314f78SAmir Goldstein /* For allocation of non-persistent inode numbers */ 864d314f78SAmir Goldstein atomic_long_t last_ino; 87c21c839bSChengguang Xu /* Whiteout dentry cache */ 88c21c839bSChengguang Xu struct dentry *whiteout; 89335d3fc5SSargun Dhillon /* r/o snapshot of upperdir sb's only taken on volatile mounts */ 90335d3fc5SSargun Dhillon errseq_t errseq; 91bbb1e54dSMiklos Szeredi }; 92bbb1e54dSMiklos Szeredi 9308f4c7c8SMiklos Szeredi static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs) 9408f4c7c8SMiklos Szeredi { 95b8e42a65SMiklos Szeredi return ofs->layers[0].mnt; 9608f4c7c8SMiklos Szeredi } 9708f4c7c8SMiklos Szeredi 98abf08576SChristian Brauner static inline struct mnt_idmap *ovl_upper_mnt_idmap(struct ovl_fs *ofs) 99abf08576SChristian Brauner { 100abf08576SChristian Brauner return mnt_idmap(ovl_upper_mnt(ofs)); 101abf08576SChristian Brauner } 102abf08576SChristian Brauner 1030f831ec8SAmir Goldstein static inline struct ovl_fs *OVL_FS(struct super_block *sb) 1040f831ec8SAmir Goldstein { 1050f831ec8SAmir Goldstein return (struct ovl_fs *)sb->s_fs_info; 1060f831ec8SAmir Goldstein } 1070f831ec8SAmir Goldstein 108c86243b0SVivek Goyal static inline bool ovl_should_sync(struct ovl_fs *ofs) 109c86243b0SVivek Goyal { 110c86243b0SVivek Goyal return !ofs->config.ovl_volatile; 111c86243b0SVivek Goyal } 112c86243b0SVivek Goyal 1135522c9c7SAmir Goldstein static inline unsigned int ovl_numlower(struct ovl_entry *oe) 1145522c9c7SAmir Goldstein { 1155522c9c7SAmir Goldstein return oe ? oe->__numlower : 0; 1165522c9c7SAmir Goldstein } 1175522c9c7SAmir Goldstein 1185522c9c7SAmir Goldstein static inline struct ovl_path *ovl_lowerstack(struct ovl_entry *oe) 1195522c9c7SAmir Goldstein { 1205522c9c7SAmir Goldstein return ovl_numlower(oe) ? oe->__lowerstack : NULL; 1215522c9c7SAmir Goldstein } 1225522c9c7SAmir Goldstein 123*ac900ed4SAmir Goldstein static inline struct ovl_path *ovl_lowerpath(struct ovl_entry *oe) 124*ac900ed4SAmir Goldstein { 125*ac900ed4SAmir Goldstein return ovl_lowerstack(oe); 126*ac900ed4SAmir Goldstein } 127*ac900ed4SAmir Goldstein 1280af950f5SAmir Goldstein /* private information held for every overlayfs dentry */ 129a6ff2bc0SAmir Goldstein static inline unsigned long *OVL_E_FLAGS(struct dentry *dentry) 130a6ff2bc0SAmir Goldstein { 1310af950f5SAmir Goldstein return (unsigned long *) &dentry->d_fsdata; 132a6ff2bc0SAmir Goldstein } 133a6ff2bc0SAmir Goldstein 13413cf199dSAmir Goldstein struct ovl_inode { 1352664bd08SVivek Goyal union { 1362664bd08SVivek Goyal struct ovl_dir_cache *cache; /* directory */ 1372664bd08SVivek Goyal struct inode *lowerdata; /* regular file */ 1382664bd08SVivek Goyal }; 139cf31c463SMiklos Szeredi const char *redirect; 14004a01ac7SMiklos Szeredi u64 version; 14113c72075SMiklos Szeredi unsigned long flags; 14213cf199dSAmir Goldstein struct inode vfs_inode; 14309d8b586SMiklos Szeredi struct dentry *__upperdentry; 1440af950f5SAmir Goldstein struct ovl_entry *oe; 145a015dafcSAmir Goldstein 146a015dafcSAmir Goldstein /* synchronize copy up and more */ 147a015dafcSAmir Goldstein struct mutex lock; 14813cf199dSAmir Goldstein }; 14913cf199dSAmir Goldstein 15013cf199dSAmir Goldstein static inline struct ovl_inode *OVL_I(struct inode *inode) 15113cf199dSAmir Goldstein { 15213cf199dSAmir Goldstein return container_of(inode, struct ovl_inode, vfs_inode); 15313cf199dSAmir Goldstein } 15409d8b586SMiklos Szeredi 1550af950f5SAmir Goldstein static inline struct ovl_entry *OVL_I_E(struct inode *inode) 1560af950f5SAmir Goldstein { 1570af950f5SAmir Goldstein return inode ? OVL_I(inode)->oe : NULL; 1580af950f5SAmir Goldstein } 1590af950f5SAmir Goldstein 1600af950f5SAmir Goldstein static inline struct ovl_entry *OVL_E(struct dentry *dentry) 1610af950f5SAmir Goldstein { 1620af950f5SAmir Goldstein return OVL_I_E(d_inode(dentry)); 1630af950f5SAmir Goldstein } 1640af950f5SAmir Goldstein 16509d8b586SMiklos Szeredi static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) 16609d8b586SMiklos Szeredi { 167506458efSWill Deacon return READ_ONCE(oi->__upperdentry); 16809d8b586SMiklos Szeredi } 169