[mirror_ubuntu-bionic-kernel.git] / fs / overlayfs / ovl_entry.h

/*
 *
 * Copyright (C) 2011 Novell Inc.
 * Copyright (C) 2016 Red Hat, 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.
 */

struct ovl_config {
	char *lowerdir;
	char *upperdir;
	char *workdir;
	bool default_permissions;
	bool redirect_dir;
	bool redirect_follow;
	const char *redirect_mode;
	bool index;
};

struct ovl_layer {
	struct vfsmount *mnt;
	dev_t pseudo_dev;
};

struct ovl_path {
	struct ovl_layer *layer;
	struct dentry *dentry;
};

/* private information held for overlayfs's superblock */
struct ovl_fs {
	struct vfsmount *upper_mnt;
	unsigned numlower;
	struct ovl_layer *lower_layers;
	/* 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;
	/* sb common to all layers */
	struct super_block *same_sb;
	/* Did we take the inuse lock? */
	bool upperdir_locked;
	bool workdir_locked;
};

/* private information held for every overlayfs dentry */
struct ovl_entry {
	union {
		struct {
			unsigned long has_upper;
			bool opaque;
		};
		struct rcu_head rcu;
	};
	unsigned numlower;
	struct ovl_path lowerstack[];
};

struct ovl_entry *ovl_alloc_entry(unsigned int numlower);

struct ovl_inode {
	struct ovl_dir_cache *cache;
	const char *redirect;
	u64 version;
	unsigned long flags;
	struct inode vfs_inode;
	struct dentry *__upperdentry;
	struct inode *lower;

	/* 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);
}
Commit	Line	Data
bbb1e54d MS	1	/*
	2	*
	3	* Copyright (C) 2011 Novell Inc.
	4	* Copyright (C) 2016 Red Hat, Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License version 2 as published by
	8	* the Free Software Foundation.
	9	*/
	10
	11	struct ovl_config {
	12	char *lowerdir;
	13	char *upperdir;
	14	char *workdir;
	15	bool default_permissions;
a6c60655	16	bool redirect_dir;
438c84c2 MS	17	bool redirect_follow;
438c84c2 MS	18	const char *redirect_mode;
02bcd157	19	bool index;
bbb1e54d MS	20	};
bbb1e54d MS	21
b9343632 CR	22	struct ovl_layer {
b9343632 CR	23	struct vfsmount *mnt;
2a9c6d06	24	dev_t pseudo_dev;
b9343632 CR	25	};
	26
	27	struct ovl_path {
	28	struct ovl_layer *layer;
	29	struct dentry *dentry;
	30	};
	31
bbb1e54d MS	32	/* private information held for overlayfs's superblock */
	33	struct ovl_fs {
	34	struct vfsmount *upper_mnt;
	35	unsigned numlower;
b9343632	36	struct ovl_layer *lower_layers;
2cac0c00 AG	37	/* workbasedir is the path at workdir= mount option */
	38	struct dentry *workbasedir;
	39	/* workdir is the 'work' directory under workbasedir */
bbb1e54d	40	struct dentry *workdir;
02bcd157 AG	41	/* index directory listing overlay inodes by origin file handle */
02bcd157 AG	42	struct dentry *indexdir;
6b2d5fe4	43	long namelen;
bbb1e54d MS	44	/* pathnames of lower and upper dirs, for show_options */
	45	struct ovl_config config;
	46	/* creds of process who forced instantiation of super block */
	47	const struct cred *creator_cred;
e7f52429	48	bool tmpfile;
82b749b2	49	bool noxattr;
7bcd74b9 AG	50	/* sb common to all layers */
7bcd74b9 AG	51	struct super_block *same_sb;
85fdee1e AG	52	/* Did we take the inuse lock? */
	53	bool upperdir_locked;
	54	bool workdir_locked;
bbb1e54d MS	55	};
	56
	57	/* private information held for every overlayfs dentry */
	58	struct ovl_entry {
bbb1e54d	59	union {
55acc661 MS	60	struct {
	61	unsigned long has_upper;
	62	bool opaque;
	63	};
bbb1e54d MS	64	struct rcu_head rcu;
	65	};
	66	unsigned numlower;
b9343632	67	struct ovl_path lowerstack[];
bbb1e54d MS	68	};
	69
	70	struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
	71
13cf199d	72	struct ovl_inode {
04a01ac7	73	struct ovl_dir_cache *cache;
cf31c463	74	const char *redirect;
04a01ac7	75	u64 version;
13c72075	76	unsigned long flags;
13cf199d	77	struct inode vfs_inode;
09d8b586	78	struct dentry *__upperdentry;
25b7713a	79	struct inode *lower;
a015dafc AG	80
	81	/* synchronize copy up and more */
	82	struct mutex lock;
13cf199d AG	83	};
	84
	85	static inline struct ovl_inode OVL_I(struct inode inode)
	86	{
	87	return container_of(inode, struct ovl_inode, vfs_inode);
	88	}
09d8b586 MS	89
	90	static inline struct dentry ovl_upperdentry_dereference(struct ovl_inode oi)
	91	{
506458ef	92	return READ_ONCE(oi->__upperdentry);
09d8b586	93	}