fs/overlayfs/overlayfs.h - kernel/msm-4.19 - Gitiles

 /*
  *
  * Copyright (C) 2011 Novell Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  */

 #include <linux/kernel.h>
 #include <linux/uuid.h>

 enum ovl_path_type {
 	__OVL_PATH_UPPER	= (1 << 0),
 	__OVL_PATH_MERGE	= (1 << 1),
 	__OVL_PATH_ORIGIN	= (1 << 2),
 };

 #define OVL_TYPE_UPPER(type)	((type) & __OVL_PATH_UPPER)
 #define OVL_TYPE_MERGE(type)	((type) & __OVL_PATH_MERGE)
 #define OVL_TYPE_ORIGIN(type)	((type) & __OVL_PATH_ORIGIN)

 #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
 #define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
 #define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
 #define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
 #define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"

 enum ovl_flag {
 	OVL_IMPURE,
 	OVL_INDEX,
 };

 /*
  * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
  * where:
  * origin.fh	- exported file handle of the lower file
  * origin.uuid	- uuid of the lower filesystem
  */
 #define OVL_FH_VERSION	0
 #define OVL_FH_MAGIC	0xfb

 /* CPU byte order required for fid decoding:  */
 #define OVL_FH_FLAG_BIG_ENDIAN	(1 << 0)
 #define OVL_FH_FLAG_ANY_ENDIAN	(1 << 1)
 /* Is the real inode encoded in fid an upper inode? */
 #define OVL_FH_FLAG_PATH_UPPER	(1 << 2)

 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
 			 OVL_FH_FLAG_PATH_UPPER)

 #if defined(__LITTLE_ENDIAN)
 #define OVL_FH_FLAG_CPU_ENDIAN 0
 #elif defined(__BIG_ENDIAN)
 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
 #else
 #error Endianness not defined
 #endif

 /* On-disk and in-memeory format for redirect by file handle */
 struct ovl_fh {
 	u8 version;	/* 0 */
 	u8 magic;	/* 0xfb */
 	u8 len;		/* size of this header + size of fid */
 	u8 flags;	/* OVL_FH_FLAG_* */
 	u8 type;	/* fid_type of fid */
 	uuid_t uuid;	/* uuid of filesystem */
 	u8 fid[0];	/* file identifier */
 } __packed;

 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	int err = vfs_rmdir(dir, dentry);
 	pr_debug("rmdir(%pd2) = %i\n", dentry, err);
 	return err;
 }

 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
 {
 	int err = vfs_unlink(dir, dentry, NULL);
 	pr_debug("unlink(%pd2) = %i\n", dentry, err);
 	return err;
 }

 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
 			      struct dentry *new_dentry, bool debug)
 {
 	int err = vfs_link(old_dentry, dir, new_dentry, NULL);
 	if (debug) {
 		pr_debug("link(%pd2, %pd2) = %i\n",
 			 old_dentry, new_dentry, err);
 	}
 	return err;
 }

 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
 			     umode_t mode, bool debug)
 {
 	int err = vfs_create(dir, dentry, mode, true);
 	if (debug)
 		pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
 	return err;
 }

 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
 			       umode_t mode, bool debug)
 {
 	int err = vfs_mkdir(dir, dentry, mode);
 	if (debug)
 		pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
 	return err;
 }

 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
 			       umode_t mode, dev_t dev, bool debug)
 {
 	int err = vfs_mknod(dir, dentry, mode, dev);
 	if (debug) {
 		pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
 			 dentry, mode, dev, err);
 	}
 	return err;
 }

 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
 				 const char *oldname, bool debug)
 {
 	int err = vfs_symlink(dir, dentry, oldname);
 	if (debug)
 		pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
 	return err;
 }

 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
 				  const void *value, size_t size, int flags)
 {
 	int err = vfs_setxattr(dentry, name, value, size, flags);
 	pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
 		 dentry, name, (int) size, (char *) value, flags, err);
 	return err;
 }

 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
 {
 	int err = vfs_removexattr(dentry, name);
 	pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
 	return err;
 }

 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
 				struct inode *newdir, struct dentry *newdentry,
 				unsigned int flags)
 {
 	int err;

 	pr_debug("rename(%pd2, %pd2, 0x%x)\n",
 		 olddentry, newdentry, flags);

 	err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);

 	if (err) {
 		pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
 			 olddentry, newdentry, err);
 	}
 	return err;
 }

 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
 {
 	int err = vfs_whiteout(dir, dentry);
 	pr_debug("whiteout(%pd2) = %i\n", dentry, err);
 	return err;
 }

 static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
 {
 	struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
 	int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;

 	pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
 	return ret;
 }

 /* util.c */
 int ovl_want_write(struct dentry *dentry);
 void ovl_drop_write(struct dentry *dentry);
 struct dentry *ovl_workdir(struct dentry *dentry);
 const struct cred *ovl_override_creds(struct super_block *sb);
 struct super_block *ovl_same_sb(struct super_block *sb);
 bool ovl_can_decode_fh(struct super_block *sb);
 struct dentry *ovl_indexdir(struct super_block *sb);
 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
 bool ovl_dentry_remote(struct dentry *dentry);
 bool ovl_dentry_weird(struct dentry *dentry);
 enum ovl_path_type ovl_path_type(struct dentry *dentry);
 void ovl_path_upper(struct dentry *dentry, struct path *path);
 void ovl_path_lower(struct dentry *dentry, struct path *path);
 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
 struct dentry *ovl_dentry_upper(struct dentry *dentry);
 struct dentry *ovl_dentry_lower(struct dentry *dentry);
 struct dentry *ovl_dentry_real(struct dentry *dentry);
 struct dentry *ovl_i_dentry_upper(struct inode *inode);
 struct inode *ovl_inode_upper(struct inode *inode);
 struct inode *ovl_inode_lower(struct inode *inode);
 struct inode *ovl_inode_real(struct inode *inode);
 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
 bool ovl_dentry_is_opaque(struct dentry *dentry);
 bool ovl_dentry_is_whiteout(struct dentry *dentry);
 void ovl_dentry_set_opaque(struct dentry *dentry);
 bool ovl_dentry_has_upper_alias(struct dentry *dentry);
 void ovl_dentry_set_upper_alias(struct dentry *dentry);
 bool ovl_redirect_dir(struct super_block *sb);
 const char *ovl_dentry_get_redirect(struct dentry *dentry);
 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
 void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
 		    struct dentry *lowerdentry);
 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
 void ovl_dentry_version_inc(struct dentry *dentry);
 u64 ovl_dentry_version_get(struct dentry *dentry);
 bool ovl_is_whiteout(struct dentry *dentry);
 struct file *ovl_path_open(struct path *path, int flags);
 int ovl_copy_up_start(struct dentry *dentry);
 void ovl_copy_up_end(struct dentry *dentry);
 bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
 int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
 		       const char *name, const void *value, size_t size,
 		       int xerr);
 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
 void ovl_set_flag(unsigned long flag, struct inode *inode);
 bool ovl_test_flag(unsigned long flag, struct inode *inode);
 bool ovl_inuse_trylock(struct dentry *dentry);
 void ovl_inuse_unlock(struct dentry *dentry);
 int ovl_nlink_start(struct dentry *dentry, bool *locked);
 void ovl_nlink_end(struct dentry *dentry, bool locked);

 static inline bool ovl_is_impuredir(struct dentry *dentry)
 {
 	return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
 }


 /* namei.c */
 int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt,
 		      struct dentry *origin, bool is_upper, bool set);
 int ovl_verify_index(struct dentry *index, struct path *lowerstack,
 		     unsigned int numlower);
 int ovl_get_index_name(struct dentry *origin, struct qstr *name);
 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
 bool ovl_lower_positive(struct dentry *dentry);

 /* readdir.c */
 extern const struct file_operations ovl_dir_operations;
 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
 void ovl_cache_free(struct list_head *list);
 int ovl_check_d_type_supported(struct path *realpath);
 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 			 struct dentry *dentry, int level);
 int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
 			 struct path *lowerstack, unsigned int numlower);

 /* inode.c */
 int ovl_set_nlink_upper(struct dentry *dentry);
 int ovl_set_nlink_lower(struct dentry *dentry);
 unsigned int ovl_get_nlink(struct dentry *lowerdentry,
 			   struct dentry *upperdentry,
 			   unsigned int fallback);
 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
 int ovl_getattr(const struct path *path, struct kstat *stat,
 		u32 request_mask, unsigned int flags);
 int ovl_permission(struct inode *inode, int mask);
 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 		  const void *value, size_t size, int flags);
 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
 		  void *value, size_t size);
 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 struct posix_acl *ovl_get_acl(struct inode *inode, int type);
 int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
 int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
 bool ovl_is_private_xattr(const char *name);

 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
 struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry);
 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 {
 	to->i_uid = from->i_uid;
 	to->i_gid = from->i_gid;
 	to->i_mode = from->i_mode;
 	to->i_atime = from->i_atime;
 	to->i_mtime = from->i_mtime;
 	to->i_ctime = from->i_ctime;
 }

 /* dir.c */
 extern const struct inode_operations ovl_dir_inode_operations;
 struct dentry *ovl_lookup_temp(struct dentry *workdir);
 struct cattr {
 	dev_t rdev;
 	umode_t mode;
 	const char *link;
 };
 int ovl_create_real(struct inode *dir, struct dentry *newdentry,
 		    struct cattr *attr,
 		    struct dentry *hardlink, bool debug);
 int ovl_cleanup(struct inode *dir, struct dentry *dentry);

 /* copy_up.c */
 int ovl_copy_up(struct dentry *dentry);
 int ovl_copy_up_flags(struct dentry *dentry, int flags);
 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 int ovl_set_attr(struct dentry *upper, struct kstat *stat);
 struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper);
	/*
	*
	* Copyright (C) 2011 Novell Inc.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*/

	#include <linux/kernel.h>
	#include <linux/uuid.h>

	enum ovl_path_type {
	__OVL_PATH_UPPER = (1 << 0),
	__OVL_PATH_MERGE = (1 << 1),
	__OVL_PATH_ORIGIN = (1 << 2),
	};

	#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
	#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
	#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)

	#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
	#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
	#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
	#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
	#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
	#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"

	enum ovl_flag {
	OVL_IMPURE,
	OVL_INDEX,
	};

	/*
	* The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
	* where:
	* origin.fh - exported file handle of the lower file
	* origin.uuid - uuid of the lower filesystem
	*/
	#define OVL_FH_VERSION 0
	#define OVL_FH_MAGIC 0xfb

	/* CPU byte order required for fid decoding: */
	#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
	#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
	/* Is the real inode encoded in fid an upper inode? */
	#define OVL_FH_FLAG_PATH_UPPER (1 << 2)

	#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN \| OVL_FH_FLAG_ANY_ENDIAN \| \
	OVL_FH_FLAG_PATH_UPPER)

	#if defined(__LITTLE_ENDIAN)
	#define OVL_FH_FLAG_CPU_ENDIAN 0
	#elif defined(__BIG_ENDIAN)
	#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
	#else
	#error Endianness not defined
	#endif

	/* On-disk and in-memeory format for redirect by file handle */
	struct ovl_fh {
	u8 version; /* 0 */
	u8 magic; /* 0xfb */
	u8 len; /* size of this header + size of fid */
	u8 flags; /* OVL_FH_FLAG_* */
	u8 type; /* fid_type of fid */
	uuid_t uuid; /* uuid of filesystem */
	u8 fid[0]; /* file identifier */
	} __packed;

	static inline int ovl_do_rmdir(struct inode dir, struct dentry dentry)
	{
	int err = vfs_rmdir(dir, dentry);
	pr_debug("rmdir(%pd2) = %i\n", dentry, err);
	return err;
	}

	static inline int ovl_do_unlink(struct inode dir, struct dentry dentry)
	{
	int err = vfs_unlink(dir, dentry, NULL);
	pr_debug("unlink(%pd2) = %i\n", dentry, err);
	return err;
	}

	static inline int ovl_do_link(struct dentry old_dentry, struct inode dir,
	struct dentry *new_dentry, bool debug)
	{
	int err = vfs_link(old_dentry, dir, new_dentry, NULL);
	if (debug) {
	pr_debug("link(%pd2, %pd2) = %i\n",
	old_dentry, new_dentry, err);
	}
	return err;
	}

	static inline int ovl_do_create(struct inode dir, struct dentry dentry,
	umode_t mode, bool debug)
	{
	int err = vfs_create(dir, dentry, mode, true);
	if (debug)
	pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
	return err;
	}

	static inline int ovl_do_mkdir(struct inode dir, struct dentry dentry,
	umode_t mode, bool debug)
	{
	int err = vfs_mkdir(dir, dentry, mode);
	if (debug)
	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
	return err;
	}

	static inline int ovl_do_mknod(struct inode dir, struct dentry dentry,
	umode_t mode, dev_t dev, bool debug)
	{
	int err = vfs_mknod(dir, dentry, mode, dev);
	if (debug) {
	pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
	dentry, mode, dev, err);
	}
	return err;
	}

	static inline int ovl_do_symlink(struct inode dir, struct dentry dentry,
	const char *oldname, bool debug)
	{
	int err = vfs_symlink(dir, dentry, oldname);
	if (debug)
	pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
	return err;
	}

	static inline int ovl_do_setxattr(struct dentry dentry, const char name,
	const void *value, size_t size, int flags)
	{
	int err = vfs_setxattr(dentry, name, value, size, flags);
	pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
	dentry, name, (int) size, (char *) value, flags, err);
	return err;
	}

	static inline int ovl_do_removexattr(struct dentry dentry, const char name)
	{
	int err = vfs_removexattr(dentry, name);
	pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
	return err;
	}

	static inline int ovl_do_rename(struct inode olddir, struct dentry olddentry,
	struct inode newdir, struct dentry newdentry,
	unsigned int flags)
	{
	int err;

	pr_debug("rename(%pd2, %pd2, 0x%x)\n",
	olddentry, newdentry, flags);

	err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);

	if (err) {
	pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
	olddentry, newdentry, err);
	}
	return err;
	}

	static inline int ovl_do_whiteout(struct inode dir, struct dentry dentry)
	{
	int err = vfs_whiteout(dir, dentry);
	pr_debug("whiteout(%pd2) = %i\n", dentry, err);
	return err;
	}

	static inline struct dentry ovl_do_tmpfile(struct dentry dentry, umode_t mode)
	{
	struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
	int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;

	pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
	return ret;
	}

	/* util.c */
	int ovl_want_write(struct dentry *dentry);
	void ovl_drop_write(struct dentry *dentry);
	struct dentry ovl_workdir(struct dentry dentry);
	const struct cred ovl_override_creds(struct super_block sb);
	struct super_block ovl_same_sb(struct super_block sb);
	bool ovl_can_decode_fh(struct super_block *sb);
	struct dentry ovl_indexdir(struct super_block sb);
	struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
	bool ovl_dentry_remote(struct dentry *dentry);
	bool ovl_dentry_weird(struct dentry *dentry);
	enum ovl_path_type ovl_path_type(struct dentry *dentry);
	void ovl_path_upper(struct dentry dentry, struct path path);
	void ovl_path_lower(struct dentry dentry, struct path path);
	enum ovl_path_type ovl_path_real(struct dentry dentry, struct path path);
	struct dentry ovl_dentry_upper(struct dentry dentry);
	struct dentry ovl_dentry_lower(struct dentry dentry);
	struct dentry ovl_dentry_real(struct dentry dentry);
	struct dentry ovl_i_dentry_upper(struct inode inode);
	struct inode ovl_inode_upper(struct inode inode);
	struct inode ovl_inode_lower(struct inode inode);
	struct inode ovl_inode_real(struct inode inode);
	struct ovl_dir_cache ovl_dir_cache(struct dentry dentry);
	void ovl_set_dir_cache(struct dentry dentry, struct ovl_dir_cache cache);
	bool ovl_dentry_is_opaque(struct dentry *dentry);
	bool ovl_dentry_is_whiteout(struct dentry *dentry);
	void ovl_dentry_set_opaque(struct dentry *dentry);
	bool ovl_dentry_has_upper_alias(struct dentry *dentry);
	void ovl_dentry_set_upper_alias(struct dentry *dentry);
	bool ovl_redirect_dir(struct super_block *sb);
	const char ovl_dentry_get_redirect(struct dentry dentry);
	void ovl_dentry_set_redirect(struct dentry dentry, const char redirect);
	void ovl_inode_init(struct inode inode, struct dentry upperdentry,
	struct dentry *lowerdentry);
	void ovl_inode_update(struct inode inode, struct dentry upperdentry);
	void ovl_dentry_version_inc(struct dentry *dentry);
	u64 ovl_dentry_version_get(struct dentry *dentry);
	bool ovl_is_whiteout(struct dentry *dentry);
	struct file ovl_path_open(struct path path, int flags);
	int ovl_copy_up_start(struct dentry *dentry);
	void ovl_copy_up_end(struct dentry *dentry);
	bool ovl_check_dir_xattr(struct dentry dentry, const char name);
	int ovl_check_setxattr(struct dentry dentry, struct dentry upperdentry,
	const char name, const void value, size_t size,
	int xerr);
	int ovl_set_impure(struct dentry dentry, struct dentry upperdentry);
	void ovl_set_flag(unsigned long flag, struct inode *inode);
	bool ovl_test_flag(unsigned long flag, struct inode *inode);
	bool ovl_inuse_trylock(struct dentry *dentry);
	void ovl_inuse_unlock(struct dentry *dentry);
	int ovl_nlink_start(struct dentry dentry, bool locked);
	void ovl_nlink_end(struct dentry *dentry, bool locked);

	static inline bool ovl_is_impuredir(struct dentry *dentry)
	{
	return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
	}


	/* namei.c */
	int ovl_verify_origin(struct dentry dentry, struct vfsmount mnt,
	struct dentry *origin, bool is_upper, bool set);
	int ovl_verify_index(struct dentry index, struct path lowerstack,
	unsigned int numlower);
	int ovl_get_index_name(struct dentry origin, struct qstr name);
	int ovl_path_next(int idx, struct dentry dentry, struct path path);
	struct dentry ovl_lookup(struct inode dir, struct dentry *dentry, unsigned int flags);
	bool ovl_lower_positive(struct dentry *dentry);

	/* readdir.c */
	extern const struct file_operations ovl_dir_operations;
	int ovl_check_empty_dir(struct dentry dentry, struct list_head list);
	void ovl_cleanup_whiteouts(struct dentry upper, struct list_head list);
	void ovl_cache_free(struct list_head *list);
	int ovl_check_d_type_supported(struct path *realpath);
	void ovl_workdir_cleanup(struct inode dir, struct vfsmount mnt,
	struct dentry *dentry, int level);
	int ovl_indexdir_cleanup(struct dentry dentry, struct vfsmount mnt,
	struct path *lowerstack, unsigned int numlower);

	/* inode.c */
	int ovl_set_nlink_upper(struct dentry *dentry);
	int ovl_set_nlink_lower(struct dentry *dentry);
	unsigned int ovl_get_nlink(struct dentry *lowerdentry,
	struct dentry *upperdentry,
	unsigned int fallback);
	int ovl_setattr(struct dentry dentry, struct iattr attr);
	int ovl_getattr(const struct path path, struct kstat stat,
	u32 request_mask, unsigned int flags);
	int ovl_permission(struct inode *inode, int mask);
	int ovl_xattr_set(struct dentry dentry, struct inode inode, const char *name,
	const void *value, size_t size, int flags);
	int ovl_xattr_get(struct dentry dentry, struct inode inode, const char *name,
	void *value, size_t size);
	ssize_t ovl_listxattr(struct dentry dentry, char list, size_t size);
	struct posix_acl ovl_get_acl(struct inode inode, int type);
	int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
	int ovl_update_time(struct inode inode, struct timespec ts, int flags);
	bool ovl_is_private_xattr(const char *name);

	struct inode ovl_new_inode(struct super_block sb, umode_t mode, dev_t rdev);
	struct inode ovl_get_inode(struct dentry dentry, struct dentry *upperdentry);
	static inline void ovl_copyattr(struct inode from, struct inode to)
	{
	to->i_uid = from->i_uid;
	to->i_gid = from->i_gid;
	to->i_mode = from->i_mode;
	to->i_atime = from->i_atime;
	to->i_mtime = from->i_mtime;
	to->i_ctime = from->i_ctime;
	}

	/* dir.c */
	extern const struct inode_operations ovl_dir_inode_operations;
	struct dentry ovl_lookup_temp(struct dentry workdir);
	struct cattr {
	dev_t rdev;
	umode_t mode;
	const char *link;
	};
	int ovl_create_real(struct inode dir, struct dentry newdentry,
	struct cattr *attr,
	struct dentry *hardlink, bool debug);
	int ovl_cleanup(struct inode dir, struct dentry dentry);

	/* copy_up.c */
	int ovl_copy_up(struct dentry *dentry);
	int ovl_copy_up_flags(struct dentry *dentry, int flags);
	int ovl_copy_xattr(struct dentry old, struct dentry new);
	int ovl_set_attr(struct dentry upper, struct kstat stat);
	struct ovl_fh ovl_encode_fh(struct dentry lower, bool is_upper);