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
22 struct 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
34 /* +1 to avoid triggering overflow warning when negating it */
35 #define KN_DEACTIVATED_BIAS (INT_MIN + 1)
36
37 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
38
39 /**
40 * kernfs_root - find out the kernfs_root a kernfs_node belongs to
41 * @kn: kernfs_node of interest
42 *
43 * Return the kernfs_root @kn belongs to.
44 */
kernfs_root(struct kernfs_node * kn)45 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
46 {
47 /* if parent exists, it's always a dir; otherwise, @sd is a dir */
48 if (kn->parent)
49 kn = kn->parent;
50 return kn->dir.root;
51 }
52
53 /*
54 * mount.c
55 */
56 struct kernfs_super_info {
57 struct super_block *sb;
58
59 /*
60 * The root associated with this super_block. Each super_block is
61 * identified by the root and ns it's associated with.
62 */
63 struct kernfs_root *root;
64
65 /*
66 * Each sb is associated with one namespace tag, currently the
67 * network namespace of the task which mounted this kernfs
68 * instance. If multiple tags become necessary, make the following
69 * an array and compare kernfs_node tag against every entry.
70 */
71 const void *ns;
72
73 /* anchored at kernfs_root->supers, protected by kernfs_rwsem */
74 struct list_head node;
75 };
76 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
77
kernfs_dentry_node(struct dentry * dentry)78 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
79 {
80 if (d_really_is_negative(dentry))
81 return NULL;
82 return d_inode(dentry)->i_private;
83 }
84
kernfs_set_rev(struct kernfs_node * parent,struct dentry * dentry)85 static inline void kernfs_set_rev(struct kernfs_node *parent,
86 struct dentry *dentry)
87 {
88 dentry->d_time = parent->dir.rev;
89 }
90
kernfs_inc_rev(struct kernfs_node * parent)91 static inline void kernfs_inc_rev(struct kernfs_node *parent)
92 {
93 parent->dir.rev++;
94 }
95
kernfs_dir_changed(struct kernfs_node * parent,struct dentry * dentry)96 static inline bool kernfs_dir_changed(struct kernfs_node *parent,
97 struct dentry *dentry)
98 {
99 if (parent->dir.rev != dentry->d_time)
100 return true;
101 return false;
102 }
103
104 extern const struct super_operations kernfs_sops;
105 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
106
107 /*
108 * inode.c
109 */
110 extern const struct xattr_handler *kernfs_xattr_handlers[];
111 void kernfs_evict_inode(struct inode *inode);
112 int kernfs_iop_permission(struct user_namespace *mnt_userns,
113 struct inode *inode, int mask);
114 int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
115 struct iattr *iattr);
116 int kernfs_iop_getattr(struct user_namespace *mnt_userns,
117 const struct path *path, struct kstat *stat,
118 u32 request_mask, unsigned int query_flags);
119 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
120 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
121
122 /*
123 * dir.c
124 */
125 extern struct rw_semaphore kernfs_rwsem;
126 extern const struct dentry_operations kernfs_dops;
127 extern const struct file_operations kernfs_dir_fops;
128 extern const struct inode_operations kernfs_dir_iops;
129
130 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
131 void kernfs_put_active(struct kernfs_node *kn);
132 int kernfs_add_one(struct kernfs_node *kn);
133 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
134 const char *name, umode_t mode,
135 kuid_t uid, kgid_t gid,
136 unsigned flags);
137
138 /*
139 * file.c
140 */
141 extern const struct file_operations kernfs_file_fops;
142
143 void kernfs_drain_open_files(struct kernfs_node *kn);
144
145 /*
146 * symlink.c
147 */
148 extern const struct inode_operations kernfs_symlink_iops;
149
150 #endif /* __KERNFS_INTERNAL_H */
151