xref: /linux/fs/tracefs/internal.h (revision 23c996fc2bc1978a02c64eddb90b4ab5d309c8df)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _TRACEFS_INTERNAL_H
3 #define _TRACEFS_INTERNAL_H
4 
5 enum {
6 	TRACEFS_EVENT_INODE		= BIT(1),
7 	TRACEFS_GID_PERM_SET		= BIT(2),
8 	TRACEFS_UID_PERM_SET		= BIT(3),
9 	TRACEFS_INSTANCE_INODE		= BIT(4),
10 };
11 
12 struct tracefs_inode {
13 	union {
14 		struct inode            vfs_inode;
15 		struct rcu_head		rcu;
16 	};
17 	/* The below gets initialized with memset_after(ti, 0, vfs_inode) */
18 	struct list_head	list;
19 	unsigned long           flags;
20 	void                    *private;
21 };
22 
23 /*
24  * struct eventfs_attr - cache the mode and ownership of a eventfs entry
25  * @mode:	saved mode plus flags of what is saved
26  * @uid:	saved uid if changed
27  * @gid:	saved gid if changed
28  */
29 struct eventfs_attr {
30 	int				mode;
31 	kuid_t				uid;
32 	kgid_t				gid;
33 };
34 
35 /*
36  * struct eventfs_inode - hold the properties of the eventfs directories.
37  * @list:	link list into the parent directory
38  * @rcu:	Union with @list for freeing
39  * @children:	link list into the child eventfs_inode
40  * @entries:	the array of entries representing the files in the directory
41  * @name:	the name of the directory to create
42  * @entry_attrs: Saved mode and ownership of the @d_children
43  * @data:	The private data to pass to the callbacks
44  * @attr:	Saved mode and ownership of eventfs_inode itself
45  * @is_freed:	Flag set if the eventfs is on its way to be freed
46  *                Note if is_freed is set, then dentry is corrupted.
47  * @is_events:	Flag set for only the top level "events" directory
48  * @nr_entries: The number of items in @entries
49  * @ino:	The saved inode number
50  */
51 struct eventfs_inode {
52 	union {
53 		struct list_head	list;
54 		struct rcu_head		rcu;
55 	};
56 	struct list_head		children;
57 	const struct eventfs_entry	*entries;
58 	const char			*name;
59 	struct eventfs_attr		*entry_attrs;
60 	void				*data;
61 	struct eventfs_attr		attr;
62 	struct kref			kref;
63 	unsigned int			is_freed:1;
64 	unsigned int			is_events:1;
65 	unsigned int			nr_entries:30;
66 	unsigned int			ino;
67 };
68 
69 static inline struct tracefs_inode *get_tracefs(const struct inode *inode)
70 {
71 	return container_of(inode, struct tracefs_inode, vfs_inode);
72 }
73 
74 struct dentry *tracefs_start_creating(const char *name, struct dentry *parent);
75 struct dentry *tracefs_end_creating(struct dentry *dentry);
76 struct dentry *tracefs_failed_creating(struct dentry *dentry);
77 struct inode *tracefs_get_inode(struct super_block *sb);
78 
79 void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid);
80 void eventfs_d_release(struct dentry *dentry);
81 
82 #endif /* _TRACEFS_INTERNAL_H */
83