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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- *
- * Copyright (C) 2011 Novell Inc.
- * Copyright (C) 2016 Red Hat, Inc.
- */
- struct ovl_config {
- char *lowerdir;
- char *upperdir;
- char *workdir;
- bool default_permissions;
- bool redirect_dir;
- bool redirect_follow;
- const char *redirect_mode;
- bool index;
- bool uuid;
- bool nfs_export;
- int xino;
- bool metacopy;
- bool userxattr;
- bool ovl_volatile;
- bool override_creds;
- };
- struct ovl_sb {
- struct super_block *sb;
- dev_t pseudo_dev;
- /* Unusable (conflicting) uuid */
- bool bad_uuid;
- /* Used as a lower layer (but maybe also as upper) */
- bool is_lower;
- };
- struct ovl_layer {
- /* ovl_free_fs() relies on @mnt being the first member! */
- struct vfsmount *mnt;
- /* Trap in ovl inode cache */
- struct inode *trap;
- struct ovl_sb *fs;
- /* Index of this layer in fs root (upper idx == 0) */
- int idx;
- /* One fsid per unique underlying sb (upper fsid == 0) */
- int fsid;
- };
- /*
- * ovl_free_fs() relies on @mnt being the first member when unmounting
- * the private mounts created for each layer. Let's check both the
- * offset and type.
- */
- static_assert(offsetof(struct ovl_layer, mnt) == 0);
- static_assert(__same_type(typeof_member(struct ovl_layer, mnt), struct vfsmount *));
- struct ovl_path {
- const struct ovl_layer *layer;
- struct dentry *dentry;
- };
- /* private information held for overlayfs's superblock */
- struct ovl_fs {
- unsigned int numlayer;
- /* Number of unique fs among layers including upper fs */
- unsigned int numfs;
- const struct ovl_layer *layers;
- struct ovl_sb *fs;
- /* workbasedir is the path at workdir= mount option */
- struct dentry *workbasedir;
- /* workdir is the 'work' directory under workbasedir */
- struct dentry *workdir;
- /* index directory listing overlay inodes by origin file handle */
- struct dentry *indexdir;
- long namelen;
- /* pathnames of lower and upper dirs, for show_options */
- struct ovl_config config;
- /* creds of process who forced instantiation of super block */
- const struct cred *creator_cred;
- bool tmpfile;
- bool noxattr;
- /* Did we take the inuse lock? */
- bool upperdir_locked;
- bool workdir_locked;
- bool share_whiteout;
- /* Traps in ovl inode cache */
- struct inode *workbasedir_trap;
- struct inode *workdir_trap;
- struct inode *indexdir_trap;
- /* -1: disabled, 0: same fs, 1..32: number of unused ino bits */
- int xino_mode;
- /* For allocation of non-persistent inode numbers */
- atomic_long_t last_ino;
- /* Whiteout dentry cache */
- struct dentry *whiteout;
- /* r/o snapshot of upperdir sb's only taken on volatile mounts */
- errseq_t errseq;
- };
- static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs)
- {
- return ofs->layers[0].mnt;
- }
- static inline struct user_namespace *ovl_upper_mnt_userns(struct ovl_fs *ofs)
- {
- return mnt_user_ns(ovl_upper_mnt(ofs));
- }
- static inline struct ovl_fs *OVL_FS(struct super_block *sb)
- {
- return (struct ovl_fs *)sb->s_fs_info;
- }
- static inline bool ovl_should_sync(struct ovl_fs *ofs)
- {
- return !ofs->config.ovl_volatile;
- }
- /* private information held for every overlayfs dentry */
- struct ovl_entry {
- union {
- struct {
- unsigned long flags;
- };
- struct rcu_head rcu;
- };
- unsigned numlower;
- struct ovl_path lowerstack[];
- };
- struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
- static inline struct ovl_entry *OVL_E(struct dentry *dentry)
- {
- return (struct ovl_entry *) dentry->d_fsdata;
- }
- struct ovl_inode {
- union {
- struct ovl_dir_cache *cache; /* directory */
- struct inode *lowerdata; /* regular file */
- };
- const char *redirect;
- u64 version;
- unsigned long flags;
- struct inode vfs_inode;
- struct dentry *__upperdentry;
- struct ovl_path lowerpath;
- /* synchronize copy up and more */
- struct mutex lock;
- };
- static inline struct ovl_inode *OVL_I(struct inode *inode)
- {
- return container_of(inode, struct ovl_inode, vfs_inode);
- }
- static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi)
- {
- return READ_ONCE(oi->__upperdentry);
- }
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