[linux-2.6-block.git] / fs / overlayfs / ovl_entry.h

/* 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 nfs_export;
	int xino;
	bool metacopy;
};

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

struct ovl_layer {
	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;
};

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;
	/* Traps in ovl inode cache */
	struct inode *upperdir_trap;
	struct inode *workbasedir_trap;
	struct inode *workdir_trap;
	struct inode *indexdir_trap;
	/* 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 {
	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 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
d2912cb1	1	/* SPDX-License-Identifier: GPL-2.0-only */
bbb1e54d MS	2	/*
	3	*
	4	* Copyright (C) 2011 Novell Inc.
	5	* Copyright (C) 2016 Red Hat, Inc.
bbb1e54d MS	6	*/
	7
	8	struct ovl_config {
	9	char *lowerdir;
	10	char *upperdir;
	11	char *workdir;
	12	bool default_permissions;
a6c60655	13	bool redirect_dir;
438c84c2 MS	14	bool redirect_follow;
438c84c2 MS	15	const char *redirect_mode;
02bcd157	16	bool index;
f168f109	17	bool nfs_export;
795939a9	18	int xino;
d5791044	19	bool metacopy;
bbb1e54d MS	20	};
bbb1e54d MS	21
5148626b AG	22	struct ovl_sb {
	23	struct super_block *sb;
	24	dev_t pseudo_dev;
	25	};
	26
b9343632 CR	27	struct ovl_layer {
b9343632 CR	28	struct vfsmount *mnt;
146d62e5 AG	29	/* Trap in ovl inode cache */
146d62e5 AG	30	struct inode *trap;
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;
146d62e5 AG	67	/* Traps in ovl inode cache */
146d62e5 AG	68	struct inode *upperdir_trap;
0be0bfd2	69	struct inode *workbasedir_trap;
146d62e5 AG	70	struct inode *workdir_trap;
146d62e5 AG	71	struct inode *indexdir_trap;
e487d889 AG	72	/* Inode numbers in all layers do not use the high xino_bits */
e487d889 AG	73	unsigned int xino_bits;
bbb1e54d MS	74	};
	75
	76	/* private information held for every overlayfs dentry */
	77	struct ovl_entry {
bbb1e54d	78	union {
55acc661	79	struct {
c62520a8	80	unsigned long flags;
55acc661	81	};
bbb1e54d MS	82	struct rcu_head rcu;
	83	};
	84	unsigned numlower;
b9343632	85	struct ovl_path lowerstack[];
bbb1e54d MS	86	};
	87
	88	struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
	89
c62520a8 AG	90	static inline struct ovl_entry OVL_E(struct dentry dentry)
	91	{
	92	return (struct ovl_entry *) dentry->d_fsdata;
	93	}
	94
13cf199d	95	struct ovl_inode {
2664bd08 VG	96	union {
	97	struct ovl_dir_cache cache; / directory */
	98	struct inode lowerdata; / regular file */
	99	};
cf31c463	100	const char *redirect;
04a01ac7	101	u64 version;
13c72075	102	unsigned long flags;
13cf199d	103	struct inode vfs_inode;
09d8b586	104	struct dentry *__upperdentry;
25b7713a	105	struct inode *lower;
a015dafc AG	106
	107	/* synchronize copy up and more */
	108	struct mutex lock;
13cf199d AG	109	};
	110
	111	static inline struct ovl_inode OVL_I(struct inode inode)
	112	{
	113	return container_of(inode, struct ovl_inode, vfs_inode);
	114	}
09d8b586 MS	115
	116	static inline struct dentry ovl_upperdentry_dereference(struct ovl_inode oi)
	117	{
506458ef	118	return READ_ONCE(oi->__upperdentry);
09d8b586	119	}