1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * fs/kernfs/kernfs-internal.h - kernfs internal header file
4 *
5 * Copyright (c) 2001-3 Patrick Mochel
6 * Copyright (c) 2007 SUSE Linux Products GmbH
7 * Copyright (c) 2007, 2013 Tejun Heo <teheo@suse.de>
8 */
9
10#ifndef __KERNFS_INTERNAL_H
11#define __KERNFS_INTERNAL_H
12
13#include <linux/lockdep.h>
14#include <linux/fs.h>
15#include <linux/mutex.h>
16#include <linux/rwsem.h>
17#include <linux/xattr.h>
18
19#include <linux/kernfs.h>
20#include <linux/fs_context.h>
21
22struct kernfs_iattrs {
23	kuid_t			ia_uid;
24	kgid_t			ia_gid;
25	struct timespec64	ia_atime;
26	struct timespec64	ia_mtime;
27	struct timespec64	ia_ctime;
28
29	struct simple_xattrs	xattrs;
30	atomic_t		nr_user_xattrs;
31	atomic_t		user_xattr_size;
32};
33
34struct kernfs_root {
35	/* published fields */
36	struct kernfs_node	*kn;
37	unsigned int		flags;	/* KERNFS_ROOT_* flags */
38
39	/* private fields, do not use outside kernfs proper */
40	struct idr		ino_idr;
41	u32			last_id_lowbits;
42	u32			id_highbits;
43	struct kernfs_syscall_ops *syscall_ops;
44
45	/* list of kernfs_super_info of this root, protected by kernfs_rwsem */
46	struct list_head	supers;
47
48	wait_queue_head_t	deactivate_waitq;
49	struct rw_semaphore	kernfs_rwsem;
50	struct rw_semaphore	kernfs_iattr_rwsem;
51	struct rw_semaphore	kernfs_supers_rwsem;
52
53	struct rcu_head		rcu;
54};
55
56/* +1 to avoid triggering overflow warning when negating it */
57#define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
58
59/* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
60
61/**
62 * kernfs_root - find out the kernfs_root a kernfs_node belongs to
63 * @kn: kernfs_node of interest
64 *
65 * Return: the kernfs_root @kn belongs to.
66 */
67static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
68{
69	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
70	if (kn->parent)
71		kn = kn->parent;
72	return kn->dir.root;
73}
74
75/*
76 * mount.c
77 */
78struct kernfs_super_info {
79	struct super_block	*sb;
80
81	/*
82	 * The root associated with this super_block.  Each super_block is
83	 * identified by the root and ns it's associated with.
84	 */
85	struct kernfs_root	*root;
86
87	/*
88	 * Each sb is associated with one namespace tag, currently the
89	 * network namespace of the task which mounted this kernfs
90	 * instance.  If multiple tags become necessary, make the following
91	 * an array and compare kernfs_node tag against every entry.
92	 */
93	const void		*ns;
94
95	/* anchored at kernfs_root->supers, protected by kernfs_rwsem */
96	struct list_head	node;
97};
98#define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
99
100static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
101{
102	if (d_really_is_negative(dentry))
103		return NULL;
104	return d_inode(dentry)->i_private;
105}
106
107static inline void kernfs_set_rev(struct kernfs_node *parent,
108				  struct dentry *dentry)
109{
110	dentry->d_time = parent->dir.rev;
111}
112
113static inline void kernfs_inc_rev(struct kernfs_node *parent)
114{
115	parent->dir.rev++;
116}
117
118static inline bool kernfs_dir_changed(struct kernfs_node *parent,
119				      struct dentry *dentry)
120{
121	if (parent->dir.rev != dentry->d_time)
122		return true;
123	return false;
124}
125
126extern const struct super_operations kernfs_sops;
127extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
128
129/*
130 * inode.c
131 */
132extern const struct xattr_handler * const kernfs_xattr_handlers[];
133void kernfs_evict_inode(struct inode *inode);
134int kernfs_iop_permission(struct mnt_idmap *idmap,
135			  struct inode *inode, int mask);
136int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
137		       struct iattr *iattr);
138int kernfs_iop_getattr(struct mnt_idmap *idmap,
139		       const struct path *path, struct kstat *stat,
140		       u32 request_mask, unsigned int query_flags);
141ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
142int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
143
144/*
145 * dir.c
146 */
147extern const struct dentry_operations kernfs_dops;
148extern const struct file_operations kernfs_dir_fops;
149extern const struct inode_operations kernfs_dir_iops;
150
151struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
152void kernfs_put_active(struct kernfs_node *kn);
153int kernfs_add_one(struct kernfs_node *kn);
154struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
155				    const char *name, umode_t mode,
156				    kuid_t uid, kgid_t gid,
157				    unsigned flags);
158
159/*
160 * file.c
161 */
162extern const struct file_operations kernfs_file_fops;
163
164bool kernfs_should_drain_open_files(struct kernfs_node *kn);
165void kernfs_drain_open_files(struct kernfs_node *kn);
166
167/*
168 * symlink.c
169 */
170extern const struct inode_operations kernfs_symlink_iops;
171
172/*
173 * kernfs locks
174 */
175extern struct kernfs_global_locks *kernfs_locks;
176#endif	/* __KERNFS_INTERNAL_H */
177