[mirror_ubuntu-artful-kernel.git] / fs / overlayfs / overlayfs.h

/*
 *
 * 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>

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

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

#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"

#define OVL_ISUPPER_MASK 1UL

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 inode *ovl_inode_real(struct inode *inode, bool *is_upper)
{
	unsigned long x = (unsigned long) READ_ONCE(inode->i_private);

	if (is_upper)
		*is_upper = x & OVL_ISUPPER_MASK;

	return (struct inode *) (x & ~OVL_ISUPPER_MASK);
}

/* 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 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 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 opaque);
void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
void ovl_inode_init(struct inode *inode, struct inode *realinode,
		    bool is_upper);
void ovl_inode_update(struct inode *inode, struct inode *upperinode);
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);

/* namei.c */
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);

/* inode.c */
int ovl_setattr(struct dentry *dentry, struct iattr *attr);
int ovl_permission(struct inode *inode, int mask);
int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
		  size_t size, int flags);
int ovl_xattr_get(struct dentry *dentry, 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 super_block *sb, struct inode *realinode);
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 dentry *dentry);
int ovl_create_real(struct inode *dir, struct dentry *newdentry,
		    struct kstat *stat, const char *link,
		    struct dentry *hardlink, bool debug);
void ovl_cleanup(struct inode *dir, struct dentry *dentry);

/* copy_up.c */
int ovl_copy_up(struct dentry *dentry);
int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
		    struct path *lowerpath, struct kstat *stat);
int ovl_copy_xattr(struct dentry *old, struct dentry *new);
int ovl_set_attr(struct dentry *upper, struct kstat *stat);
Commit	Line	Data
e9be9d5e MS	1	/*
	2	*
	3	* Copyright (C) 2011 Novell Inc.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*/
	9
	10	#include <linux/kernel.h>
	11
e9be9d5e	12	enum ovl_path_type {
38e813db MS	13	__OVL_PATH_UPPER = (1 << 0),
38e813db MS	14	__OVL_PATH_MERGE = (1 << 1),
e9be9d5e MS	15	};
e9be9d5e MS	16
1afaba1e MS	17	#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
1afaba1e MS	18	#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
d837a49b	19
fe2b7595 AG	20	#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
fe2b7595 AG	21	#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
e9be9d5e	22
39b681f8 MS	23	#define OVL_ISUPPER_MASK 1UL
39b681f8 MS	24
e9be9d5e MS	25	static inline int ovl_do_rmdir(struct inode dir, struct dentry dentry)
	26	{
	27	int err = vfs_rmdir(dir, dentry);
	28	pr_debug("rmdir(%pd2) = %i\n", dentry, err);
	29	return err;
	30	}
	31
	32	static inline int ovl_do_unlink(struct inode dir, struct dentry dentry)
	33	{
	34	int err = vfs_unlink(dir, dentry, NULL);
	35	pr_debug("unlink(%pd2) = %i\n", dentry, err);
	36	return err;
	37	}
	38
	39	static inline int ovl_do_link(struct dentry old_dentry, struct inode dir,
	40	struct dentry *new_dentry, bool debug)
	41	{
	42	int err = vfs_link(old_dentry, dir, new_dentry, NULL);
	43	if (debug) {
	44	pr_debug("link(%pd2, %pd2) = %i\n",
	45	old_dentry, new_dentry, err);
	46	}
	47	return err;
	48	}
	49
	50	static inline int ovl_do_create(struct inode dir, struct dentry dentry,
	51	umode_t mode, bool debug)
	52	{
	53	int err = vfs_create(dir, dentry, mode, true);
	54	if (debug)
	55	pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
	56	return err;
	57	}
	58
	59	static inline int ovl_do_mkdir(struct inode dir, struct dentry dentry,
	60	umode_t mode, bool debug)
	61	{
	62	int err = vfs_mkdir(dir, dentry, mode);
	63	if (debug)
	64	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
	65	return err;
	66	}
	67
	68	static inline int ovl_do_mknod(struct inode dir, struct dentry dentry,
	69	umode_t mode, dev_t dev, bool debug)
	70	{
	71	int err = vfs_mknod(dir, dentry, mode, dev);
	72	if (debug) {
	73	pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
	74	dentry, mode, dev, err);
	75	}
	76	return err;
	77	}
	78
	79	static inline int ovl_do_symlink(struct inode dir, struct dentry dentry,
	80	const char *oldname, bool debug)
	81	{
	82	int err = vfs_symlink(dir, dentry, oldname);
	83	if (debug)
	84	pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
	85	return err;
	86	}
	87
	88	static inline int ovl_do_setxattr(struct dentry dentry, const char name,
89	const void *value, size_t size, int flags)
90	{
91	int err = vfs_setxattr(dentry, name, value, size, flags);
92	pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
93	dentry, name, (int) size, (char *) value, flags, err);
94	return err;
95	}
96
97	static inline int ovl_do_removexattr(struct dentry dentry, const char name)
98	{
99	int err = vfs_removexattr(dentry, name);
100	pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
101	return err;
102	}
103
104	static inline int ovl_do_rename(struct inode olddir, struct dentry olddentry,
105	struct inode newdir, struct dentry newdentry,
106	unsigned int flags)
107	{
108	int err;
109
2773bf00	110	pr_debug("rename(%pd2, %pd2, 0x%x)\n",
e9be9d5e MS	111	olddentry, newdentry, flags);
	112
	113	err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
	114
	115	if (err) {
2773bf00	116	pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
e9be9d5e MS	117	olddentry, newdentry, err);
	118	}
	119	return err;
	120	}
	121
	122	static inline int ovl_do_whiteout(struct inode dir, struct dentry dentry)
	123	{
	124	int err = vfs_whiteout(dir, dentry);
	125	pr_debug("whiteout(%pd2) = %i\n", dentry, err);
	126	return err;
	127	}
	128
39b681f8 MS	129	static inline struct inode ovl_inode_real(struct inode inode, bool *is_upper)
	130	{
	131	unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
	132
	133	if (is_upper)
	134	*is_upper = x & OVL_ISUPPER_MASK;
	135
	136	return (struct inode *) (x & ~OVL_ISUPPER_MASK);
	137	}
	138
bbb1e54d MS	139	/* util.c */
	140	int ovl_want_write(struct dentry *dentry);
	141	void ovl_drop_write(struct dentry *dentry);
	142	struct dentry ovl_workdir(struct dentry dentry);
	143	const struct cred ovl_override_creds(struct super_block sb);
	144	struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
	145	bool ovl_dentry_remote(struct dentry *dentry);
	146	bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e	147	enum ovl_path_type ovl_path_type(struct dentry *dentry);
e9be9d5e MS	148	void ovl_path_upper(struct dentry dentry, struct path path);
	149	void ovl_path_lower(struct dentry dentry, struct path path);
	150	enum ovl_path_type ovl_path_real(struct dentry dentry, struct path path);
	151	struct dentry ovl_dentry_upper(struct dentry dentry);
	152	struct dentry ovl_dentry_lower(struct dentry dentry);
	153	struct dentry ovl_dentry_real(struct dentry dentry);
e9be9d5e MS	154	struct ovl_dir_cache ovl_dir_cache(struct dentry dentry);
e9be9d5e MS	155	void ovl_set_dir_cache(struct dentry dentry, struct ovl_dir_cache cache);
e9be9d5e	156	bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49	157	bool ovl_dentry_is_whiteout(struct dentry *dentry);
e9be9d5e	158	void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
e9be9d5e	159	void ovl_dentry_update(struct dentry dentry, struct dentry upperdentry);
bbb1e54d MS	160	void ovl_inode_init(struct inode inode, struct inode realinode,
bbb1e54d MS	161	bool is_upper);
39b681f8	162	void ovl_inode_update(struct inode inode, struct inode upperinode);
bbb1e54d MS	163	void ovl_dentry_version_inc(struct dentry *dentry);
	164	u64 ovl_dentry_version_get(struct dentry *dentry);
	165	bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e MS	166	struct file ovl_path_open(struct path path, int flags);
e9be9d5e MS	167
bbb1e54d MS	168	/* namei.c */
	169	int ovl_path_next(int idx, struct dentry dentry, struct path path);
	170	struct dentry ovl_lookup(struct inode dir, struct dentry *dentry, unsigned int flags);
	171	bool ovl_lower_positive(struct dentry *dentry);
e9be9d5e MS	172
	173	/* readdir.c */
	174	extern const struct file_operations ovl_dir_operations;
	175	int ovl_check_empty_dir(struct dentry dentry, struct list_head list);
	176	void ovl_cleanup_whiteouts(struct dentry upper, struct list_head list);
	177	void ovl_cache_free(struct list_head *list);
45aebeaf	178	int ovl_check_d_type_supported(struct path *realpath);
eea2fb48 MS	179	void ovl_workdir_cleanup(struct inode dir, struct vfsmount mnt,
eea2fb48 MS	180	struct dentry *dentry, int level);
e9be9d5e MS	181
	182	/* inode.c */
	183	int ovl_setattr(struct dentry dentry, struct iattr attr);
	184	int ovl_permission(struct inode *inode, int mask);
0e585ccc AG	185	int ovl_xattr_set(struct dentry dentry, const char name, const void *value,
0e585ccc AG	186	size_t size, int flags);
0eb45fc3 AG	187	int ovl_xattr_get(struct dentry dentry, const char name,
0eb45fc3 AG	188	void *value, size_t size);
e9be9d5e	189	ssize_t ovl_listxattr(struct dentry dentry, char list, size_t size);
39a25b2b	190	struct posix_acl ovl_get_acl(struct inode inode, int type);
2d902671	191	int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
d719e8f2	192	int ovl_update_time(struct inode inode, struct timespec ts, int flags);
0956254a	193	bool ovl_is_private_xattr(const char *name);
e9be9d5e	194
ca4c8a3a	195	struct inode ovl_new_inode(struct super_block sb, umode_t mode, dev_t rdev);
51f7e52d	196	struct inode ovl_get_inode(struct super_block sb, struct inode *realinode);
e9be9d5e MS	197	static inline void ovl_copyattr(struct inode from, struct inode to)
	198	{
	199	to->i_uid = from->i_uid;
	200	to->i_gid = from->i_gid;
07a2daab	201	to->i_mode = from->i_mode;
d719e8f2 MS	202	to->i_atime = from->i_atime;
	203	to->i_mtime = from->i_mtime;
	204	to->i_ctime = from->i_ctime;
e9be9d5e MS	205	}
	206
	207	/* dir.c */
	208	extern const struct inode_operations ovl_dir_inode_operations;
	209	struct dentry ovl_lookup_temp(struct dentry workdir, struct dentry *dentry);
	210	int ovl_create_real(struct inode dir, struct dentry newdentry,
	211	struct kstat stat, const char link,
	212	struct dentry *hardlink, bool debug);
	213	void ovl_cleanup(struct inode dir, struct dentry dentry);
	214
	215	/* copy_up.c */
	216	int ovl_copy_up(struct dentry *dentry);
	217	int ovl_copy_up_one(struct dentry parent, struct dentry dentry,
0f7ff2da	218	struct path lowerpath, struct kstat stat);
e9be9d5e MS	219	int ovl_copy_xattr(struct dentry old, struct dentry new);
e9be9d5e MS	220	int ovl_set_attr(struct dentry upper, struct kstat stat);