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 struct 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 };
51
52 /* +1 to avoid triggering overflow warning when negating it */
53 #define KN_DEACTIVATED_BIAS (INT_MIN + 1)
54
55 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
56
57 /**
58 * kernfs_root - find out the kernfs_root a kernfs_node belongs to
59 * @kn: kernfs_node of interest
60 *
61 * Return the kernfs_root @kn belongs to.
62 */
kernfs_root(struct kernfs_node * kn)63 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
64 {
65 /* if parent exists, it's always a dir; otherwise, @sd is a dir */
66 if (kn->parent)
67 kn = kn->parent;
68 return kn->dir.root;
69 }
70
71 /*
72 * mount.c
73 */
74 struct kernfs_super_info {
75 struct super_block *sb;
76
77 /*
78 * The root associated with this super_block. Each super_block is
79 * identified by the root and ns it's associated with.
80 */
81 struct kernfs_root *root;
82
83 /*
84 * Each sb is associated with one namespace tag, currently the
85 * network namespace of the task which mounted this kernfs
86 * instance. If multiple tags become necessary, make the following
87 * an array and compare kernfs_node tag against every entry.
88 */
89 const void *ns;
90
91 /* anchored at kernfs_root->supers, protected by kernfs_rwsem */
92 struct list_head node;
93 };
94 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
95
kernfs_dentry_node(struct dentry * dentry)96 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
97 {
98 if (d_really_is_negative(dentry))
99 return NULL;
100 return d_inode(dentry)->i_private;
101 }
102
kernfs_set_rev(struct kernfs_node * parent,struct dentry * dentry)103 static inline void kernfs_set_rev(struct kernfs_node *parent,
104 struct dentry *dentry)
105 {
106 dentry->d_time = parent->dir.rev;
107 }
108
kernfs_inc_rev(struct kernfs_node * parent)109 static inline void kernfs_inc_rev(struct kernfs_node *parent)
110 {
111 parent->dir.rev++;
112 }
113
kernfs_dir_changed(struct kernfs_node * parent,struct dentry * dentry)114 static inline bool kernfs_dir_changed(struct kernfs_node *parent,
115 struct dentry *dentry)
116 {
117 if (parent->dir.rev != dentry->d_time)
118 return true;
119 return false;
120 }
121
122 extern const struct super_operations kernfs_sops;
123 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
124
125 /*
126 * inode.c
127 */
128 extern const struct xattr_handler *kernfs_xattr_handlers[];
129 void kernfs_evict_inode(struct inode *inode);
130 int kernfs_iop_permission(struct user_namespace *mnt_userns,
131 struct inode *inode, int mask);
132 int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
133 struct iattr *iattr);
134 int kernfs_iop_getattr(struct user_namespace *mnt_userns,
135 const struct path *path, struct kstat *stat,
136 u32 request_mask, unsigned int query_flags);
137 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
138 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
139
140 /*
141 * dir.c
142 */
143 extern const struct dentry_operations kernfs_dops;
144 extern const struct file_operations kernfs_dir_fops;
145 extern const struct inode_operations kernfs_dir_iops;
146
147 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
148 void kernfs_put_active(struct kernfs_node *kn);
149 int kernfs_add_one(struct kernfs_node *kn);
150 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
151 const char *name, umode_t mode,
152 kuid_t uid, kgid_t gid,
153 unsigned flags);
154
155 /*
156 * file.c
157 */
158 extern const struct file_operations kernfs_file_fops;
159
160 bool kernfs_should_drain_open_files(struct kernfs_node *kn);
161 void kernfs_drain_open_files(struct kernfs_node *kn);
162
163 /*
164 * symlink.c
165 */
166 extern const struct inode_operations kernfs_symlink_iops;
167
168 /*
169 * kernfs locks
170 */
171 extern struct kernfs_global_locks *kernfs_locks;
172 #endif /* __KERNFS_INTERNAL_H */
173