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 *upperdir; 10bbb1e54dSMiklos Szeredi char *workdir; 11*a535116dSAmir Goldstein char **lowerdirs; 12bbb1e54dSMiklos Szeredi bool default_permissions; 13af5f2396SAmir Goldstein int redirect_mode; 14ae8cba40SAlexander Larsson int verity_mode; 1502bcd157SAmir Goldstein bool index; 16b0504bfeSAmir Goldstein int uuid; 17f168f109SAmir Goldstein bool nfs_export; 18795939a9SAmir Goldstein int xino; 19d5791044SVivek Goyal bool metacopy; 202d2f2d73SMiklos Szeredi bool userxattr; 21c86243b0SVivek Goyal bool ovl_volatile; 22bbb1e54dSMiklos Szeredi }; 23bbb1e54dSMiklos Szeredi 245148626bSAmir Goldstein struct ovl_sb { 255148626bSAmir Goldstein struct super_block *sb; 265148626bSAmir Goldstein dev_t pseudo_dev; 277e63c87fSAmir Goldstein /* Unusable (conflicting) uuid */ 287e63c87fSAmir Goldstein bool bad_uuid; 291b81ddddSAmir Goldstein /* Used as a lower layer (but maybe also as upper) */ 301b81ddddSAmir Goldstein bool is_lower; 315148626bSAmir Goldstein }; 325148626bSAmir Goldstein 33b9343632SChandan Rajendra struct ovl_layer { 34f723edb8SChristian Brauner /* ovl_free_fs() relies on @mnt being the first member! */ 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; 6037ebf056SAmir Goldstein /* Number of data-only lower layers */ 6137ebf056SAmir Goldstein unsigned int numdatalayer; 6213464165SMiklos Szeredi const struct ovl_layer *layers; 6307f1e596SAmir Goldstein struct ovl_sb *fs; 642cac0c00SAmir Goldstein /* workbasedir is the path at workdir= mount option */ 652cac0c00SAmir Goldstein struct dentry *workbasedir; 662cac0c00SAmir Goldstein /* workdir is the 'work' directory under workbasedir */ 67bbb1e54dSMiklos Szeredi struct dentry *workdir; 6802bcd157SAmir Goldstein /* index directory listing overlay inodes by origin file handle */ 6902bcd157SAmir Goldstein struct dentry *indexdir; 706b2d5fe4SMiklos Szeredi long namelen; 71bbb1e54dSMiklos Szeredi /* pathnames of lower and upper dirs, for show_options */ 72bbb1e54dSMiklos Szeredi struct ovl_config config; 73bbb1e54dSMiklos Szeredi /* creds of process who forced instantiation of super block */ 74bbb1e54dSMiklos Szeredi const struct cred *creator_cred; 75e7f52429SAmir Goldstein bool tmpfile; 7682b749b2SAmir Goldstein bool noxattr; 7716aac5adSAmir Goldstein bool nofh; 7885fdee1eSAmir Goldstein /* Did we take the inuse lock? */ 7985fdee1eSAmir Goldstein bool upperdir_locked; 8085fdee1eSAmir Goldstein bool workdir_locked; 81146d62e5SAmir Goldstein /* Traps in ovl inode cache */ 820be0bfd2SAmir Goldstein struct inode *workbasedir_trap; 83146d62e5SAmir Goldstein struct inode *workdir_trap; 84146d62e5SAmir Goldstein struct inode *indexdir_trap; 850f831ec8SAmir Goldstein /* -1: disabled, 0: same fs, 1..32: number of unused ino bits */ 860f831ec8SAmir Goldstein int xino_mode; 874d314f78SAmir Goldstein /* For allocation of non-persistent inode numbers */ 884d314f78SAmir Goldstein atomic_long_t last_ino; 89e4599d4bSAmir Goldstein /* Shared whiteout cache */ 90c21c839bSChengguang Xu struct dentry *whiteout; 91e4599d4bSAmir Goldstein bool no_shared_whiteout; 92335d3fc5SSargun Dhillon /* r/o snapshot of upperdir sb's only taken on volatile mounts */ 93335d3fc5SSargun Dhillon errseq_t errseq; 94bbb1e54dSMiklos Szeredi }; 95bbb1e54dSMiklos Szeredi 9637ebf056SAmir Goldstein /* Number of lower layers, not including data-only layers */ ovl_numlowerlayer(struct ovl_fs * ofs)9737ebf056SAmir Goldsteinstatic inline unsigned int ovl_numlowerlayer(struct ovl_fs *ofs) 9837ebf056SAmir Goldstein { 9937ebf056SAmir Goldstein return ofs->numlayer - ofs->numdatalayer - 1; 10037ebf056SAmir Goldstein } 10137ebf056SAmir Goldstein ovl_upper_mnt(struct ovl_fs * ofs)10208f4c7c8SMiklos Szeredistatic inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs) 10308f4c7c8SMiklos Szeredi { 104b8e42a65SMiklos Szeredi return ofs->layers[0].mnt; 10508f4c7c8SMiklos Szeredi } 10608f4c7c8SMiklos Szeredi ovl_upper_mnt_idmap(struct ovl_fs * ofs)107abf08576SChristian Braunerstatic inline struct mnt_idmap *ovl_upper_mnt_idmap(struct ovl_fs *ofs) 108abf08576SChristian Brauner { 109abf08576SChristian Brauner return mnt_idmap(ovl_upper_mnt(ofs)); 110abf08576SChristian Brauner } 111abf08576SChristian Brauner 112f01d0889SAndrea Righi extern struct file_system_type ovl_fs_type; 113f01d0889SAndrea Righi OVL_FS(struct super_block * sb)1140f831ec8SAmir Goldsteinstatic inline struct ovl_fs *OVL_FS(struct super_block *sb) 1150f831ec8SAmir Goldstein { 116adcd459fSAndrea Righi if (IS_ENABLED(CONFIG_OVERLAY_FS_DEBUG)) 117adcd459fSAndrea Righi WARN_ON_ONCE(sb->s_type != &ovl_fs_type); 118adcd459fSAndrea Righi 1190f831ec8SAmir Goldstein return (struct ovl_fs *)sb->s_fs_info; 1200f831ec8SAmir Goldstein } 1210f831ec8SAmir Goldstein ovl_should_sync(struct ovl_fs * ofs)122c86243b0SVivek Goyalstatic inline bool ovl_should_sync(struct ovl_fs *ofs) 123c86243b0SVivek Goyal { 124c86243b0SVivek Goyal return !ofs->config.ovl_volatile; 125c86243b0SVivek Goyal } 126c86243b0SVivek Goyal ovl_numlower(struct ovl_entry * oe)1275522c9c7SAmir Goldsteinstatic inline unsigned int ovl_numlower(struct ovl_entry *oe) 1285522c9c7SAmir Goldstein { 1295522c9c7SAmir Goldstein return oe ? oe->__numlower : 0; 1305522c9c7SAmir Goldstein } 1315522c9c7SAmir Goldstein ovl_lowerstack(struct ovl_entry * oe)1325522c9c7SAmir Goldsteinstatic inline struct ovl_path *ovl_lowerstack(struct ovl_entry *oe) 1335522c9c7SAmir Goldstein { 1345522c9c7SAmir Goldstein return ovl_numlower(oe) ? oe->__lowerstack : NULL; 1355522c9c7SAmir Goldstein } 1365522c9c7SAmir Goldstein ovl_lowerpath(struct ovl_entry * oe)137ac900ed4SAmir Goldsteinstatic inline struct ovl_path *ovl_lowerpath(struct ovl_entry *oe) 138ac900ed4SAmir Goldstein { 139ac900ed4SAmir Goldstein return ovl_lowerstack(oe); 140ac900ed4SAmir Goldstein } 141ac900ed4SAmir Goldstein ovl_lowerdata(struct ovl_entry * oe)142ab1eb5ffSAmir Goldsteinstatic inline struct ovl_path *ovl_lowerdata(struct ovl_entry *oe) 143ab1eb5ffSAmir Goldstein { 144ab1eb5ffSAmir Goldstein struct ovl_path *lowerstack = ovl_lowerstack(oe); 145ab1eb5ffSAmir Goldstein 146ab1eb5ffSAmir Goldstein return lowerstack ? &lowerstack[oe->__numlower - 1] : NULL; 147ab1eb5ffSAmir Goldstein } 148ab1eb5ffSAmir Goldstein 1492b21da92SAmir Goldstein /* May return NULL if lazy lookup of lowerdata is needed */ ovl_lowerdata_dentry(struct ovl_entry * oe)150ab1eb5ffSAmir Goldsteinstatic inline struct dentry *ovl_lowerdata_dentry(struct ovl_entry *oe) 151ab1eb5ffSAmir Goldstein { 152ab1eb5ffSAmir Goldstein struct ovl_path *lowerdata = ovl_lowerdata(oe); 153ab1eb5ffSAmir Goldstein 15442dd69aeSAmir Goldstein return lowerdata ? READ_ONCE(lowerdata->dentry) : NULL; 155ab1eb5ffSAmir Goldstein } 156ab1eb5ffSAmir Goldstein 1570af950f5SAmir Goldstein /* private information held for every overlayfs dentry */ OVL_E_FLAGS(struct dentry * dentry)158a6ff2bc0SAmir Goldsteinstatic inline unsigned long *OVL_E_FLAGS(struct dentry *dentry) 159a6ff2bc0SAmir Goldstein { 1600af950f5SAmir Goldstein return (unsigned long *) &dentry->d_fsdata; 161a6ff2bc0SAmir Goldstein } 162a6ff2bc0SAmir Goldstein 16313cf199dSAmir Goldstein struct ovl_inode { 1642664bd08SVivek Goyal union { 1652664bd08SVivek Goyal struct ovl_dir_cache *cache; /* directory */ 1662b21da92SAmir Goldstein const char *lowerdata_redirect; /* regular file */ 1672664bd08SVivek Goyal }; 168cf31c463SMiklos Szeredi const char *redirect; 16904a01ac7SMiklos Szeredi u64 version; 17013c72075SMiklos Szeredi unsigned long flags; 17113cf199dSAmir Goldstein struct inode vfs_inode; 17209d8b586SMiklos Szeredi struct dentry *__upperdentry; 1730af950f5SAmir Goldstein struct ovl_entry *oe; 174a015dafcSAmir Goldstein 175a015dafcSAmir Goldstein /* synchronize copy up and more */ 176a015dafcSAmir Goldstein struct mutex lock; 17713cf199dSAmir Goldstein }; 17813cf199dSAmir Goldstein OVL_I(struct inode * inode)17913cf199dSAmir Goldsteinstatic inline struct ovl_inode *OVL_I(struct inode *inode) 18013cf199dSAmir Goldstein { 18113cf199dSAmir Goldstein return container_of(inode, struct ovl_inode, vfs_inode); 18213cf199dSAmir Goldstein } 18309d8b586SMiklos Szeredi OVL_I_E(struct inode * inode)1840af950f5SAmir Goldsteinstatic inline struct ovl_entry *OVL_I_E(struct inode *inode) 1850af950f5SAmir Goldstein { 1860af950f5SAmir Goldstein return inode ? OVL_I(inode)->oe : NULL; 1870af950f5SAmir Goldstein } 1880af950f5SAmir Goldstein OVL_E(struct dentry * dentry)1890af950f5SAmir Goldsteinstatic inline struct ovl_entry *OVL_E(struct dentry *dentry) 1900af950f5SAmir Goldstein { 1910af950f5SAmir Goldstein return OVL_I_E(d_inode(dentry)); 1920af950f5SAmir Goldstein } 1930af950f5SAmir Goldstein ovl_upperdentry_dereference(struct ovl_inode * oi)19409d8b586SMiklos Szeredistatic inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) 19509d8b586SMiklos Szeredi { 196506458efSWill Deacon return READ_ONCE(oi->__upperdentry); 19709d8b586SMiklos Szeredi } 198