[mirror_ubuntu-artful-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 index;
};

/* private information held for overlayfs's superblock */
struct ovl_fs {
	struct vfsmount *upper_mnt;
	unsigned numlower;
	struct vfsmount **lower_mnt;
	/* 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;
};

/* 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 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 lockless_dereference(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;
02bcd157	17	bool index;
bbb1e54d MS	18	};
	19
	20	/* private information held for overlayfs's superblock */
	21	struct ovl_fs {
	22	struct vfsmount *upper_mnt;
	23	unsigned numlower;
	24	struct vfsmount **lower_mnt;
2cac0c00 AG	25	/* workbasedir is the path at workdir= mount option */
	26	struct dentry *workbasedir;
	27	/* workdir is the 'work' directory under workbasedir */
bbb1e54d	28	struct dentry *workdir;
02bcd157 AG	29	/* index directory listing overlay inodes by origin file handle */
02bcd157 AG	30	struct dentry *indexdir;
6b2d5fe4	31	long namelen;
bbb1e54d MS	32	/* pathnames of lower and upper dirs, for show_options */
	33	struct ovl_config config;
	34	/* creds of process who forced instantiation of super block */
	35	const struct cred *creator_cred;
e7f52429	36	bool tmpfile;
82b749b2	37	bool noxattr;
7bcd74b9 AG	38	/* sb common to all layers */
7bcd74b9 AG	39	struct super_block *same_sb;
bbb1e54d MS	40	};
	41
	42	/* private information held for every overlayfs dentry */
	43	struct ovl_entry {
bbb1e54d	44	union {
55acc661 MS	45	struct {
	46	unsigned long has_upper;
	47	bool opaque;
	48	};
bbb1e54d MS	49	struct rcu_head rcu;
	50	};
	51	unsigned numlower;
	52	struct path lowerstack[];
	53	};
	54
	55	struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
	56
13cf199d	57	struct ovl_inode {
04a01ac7	58	struct ovl_dir_cache *cache;
cf31c463	59	const char *redirect;
04a01ac7	60	u64 version;
13c72075	61	unsigned long flags;
13cf199d	62	struct inode vfs_inode;
09d8b586	63	struct dentry *__upperdentry;
25b7713a	64	struct inode *lower;
a015dafc AG	65
	66	/* synchronize copy up and more */
	67	struct mutex lock;
13cf199d AG	68	};
	69
	70	static inline struct ovl_inode OVL_I(struct inode inode)
	71	{
	72	return container_of(inode, struct ovl_inode, vfs_inode);
	73	}
09d8b586 MS	74
	75	static inline struct dentry ovl_upperdentry_dereference(struct ovl_inode oi)
	76	{
	77	return lockless_dereference(oi->__upperdentry);
	78	}