[linux-block.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;
	bool nfs_export;
	int xino;
};

struct ovl_sb {
	struct super_block *sb;
	dev_t pseudo_dev;
};

struct ovl_layer {
	struct vfsmount *mnt;
	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;
};

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 int numlower;
	/* Number of unique lower sb that differ from upper sb */
	unsigned int numlowerfs;
	struct ovl_layer *lower_layers;
	struct ovl_sb *lower_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;
	/* Inode numbers in all layers do not use the high xino_bits */
	unsigned int xino_bits;
};

/* 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 {
	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;
f168f109	20	bool nfs_export;
795939a9	21	int xino;
bbb1e54d MS	22	};
bbb1e54d MS	23
5148626b AG	24	struct ovl_sb {
	25	struct super_block *sb;
	26	dev_t pseudo_dev;
	27	};
	28
b9343632 CR	29	struct ovl_layer {
b9343632 CR	30	struct vfsmount *mnt;
5148626b AG	31	struct ovl_sb *fs;
5148626b AG	32	/* Index of this layer in fs root (upper idx == 0) */
d583ed7d	33	int idx;
5148626b AG	34	/* One fsid per unique underlying sb (upper fsid == 0) */
5148626b AG	35	int fsid;
b9343632 CR	36	};
	37
	38	struct ovl_path {
	39	struct ovl_layer *layer;
	40	struct dentry *dentry;
	41	};
	42
bbb1e54d MS	43	/* private information held for overlayfs's superblock */
	44	struct ovl_fs {
	45	struct vfsmount *upper_mnt;
5148626b AG	46	unsigned int numlower;
	47	/* Number of unique lower sb that differ from upper sb */
	48	unsigned int numlowerfs;
b9343632	49	struct ovl_layer *lower_layers;
5148626b	50	struct ovl_sb *lower_fs;
2cac0c00 AG	51	/* workbasedir is the path at workdir= mount option */
	52	struct dentry *workbasedir;
	53	/* workdir is the 'work' directory under workbasedir */
bbb1e54d	54	struct dentry *workdir;
02bcd157 AG	55	/* index directory listing overlay inodes by origin file handle */
02bcd157 AG	56	struct dentry *indexdir;
6b2d5fe4	57	long namelen;
bbb1e54d MS	58	/* pathnames of lower and upper dirs, for show_options */
	59	struct ovl_config config;
	60	/* creds of process who forced instantiation of super block */
	61	const struct cred *creator_cred;
e7f52429	62	bool tmpfile;
82b749b2	63	bool noxattr;
85fdee1e AG	64	/* Did we take the inuse lock? */
	65	bool upperdir_locked;
	66	bool workdir_locked;
e487d889 AG	67	/* Inode numbers in all layers do not use the high xino_bits */
e487d889 AG	68	unsigned int xino_bits;
bbb1e54d MS	69	};
	70
	71	/* private information held for every overlayfs dentry */
	72	struct ovl_entry {
bbb1e54d	73	union {
55acc661	74	struct {
c62520a8	75	unsigned long flags;
55acc661	76	};
bbb1e54d MS	77	struct rcu_head rcu;
	78	};
	79	unsigned numlower;
b9343632	80	struct ovl_path lowerstack[];
bbb1e54d MS	81	};
	82
	83	struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
	84
c62520a8 AG	85	static inline struct ovl_entry OVL_E(struct dentry dentry)
	86	{
	87	return (struct ovl_entry *) dentry->d_fsdata;
	88	}
	89
13cf199d	90	struct ovl_inode {
04a01ac7	91	struct ovl_dir_cache *cache;
cf31c463	92	const char *redirect;
04a01ac7	93	u64 version;
13c72075	94	unsigned long flags;
13cf199d	95	struct inode vfs_inode;
09d8b586	96	struct dentry *__upperdentry;
25b7713a	97	struct inode *lower;
a015dafc AG	98
	99	/* synchronize copy up and more */
	100	struct mutex lock;
13cf199d AG	101	};
	102
	103	static inline struct ovl_inode OVL_I(struct inode inode)
	104	{
	105	return container_of(inode, struct ovl_inode, vfs_inode);
	106	}
09d8b586 MS	107
	108	static inline struct dentry ovl_upperdentry_dereference(struct ovl_inode oi)
	109	{
506458ef	110	return READ_ONCE(oi->__upperdentry);
09d8b586	111	}