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 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 */
67 static 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 */
78 struct 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
100 static 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
107 static inline void kernfs_set_rev(struct kernfs_node *parent,
108 struct dentry *dentry)
109 {
110 dentry->d_time = parent->dir.rev;
111 }
112
113 static inline void kernfs_inc_rev(struct kernfs_node *parent)
114 {
115 parent->dir.rev++;
116 }
117
118 static 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
126 extern const struct super_operations kernfs_sops;
127 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
128
129 /*
130 * inode.c
131 */
132 extern const struct xattr_handler * const kernfs_xattr_handlers[];
133 void kernfs_evict_inode(struct inode *inode);
134 int kernfs_iop_permission(struct mnt_idmap *idmap,
135 struct inode *inode, int mask);
136 int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
137 struct iattr *iattr);
138 int kernfs_iop_getattr(struct mnt_idmap *idmap,
139 const struct path *path, struct kstat *stat,
140 u32 request_mask, unsigned int query_flags);
141 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
142 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
143
144 /*
145 * dir.c
146 */
147 extern const struct dentry_operations kernfs_dops;
148 extern const struct file_operations kernfs_dir_fops;
149 extern const struct inode_operations kernfs_dir_iops;
150
151 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
152 void kernfs_put_active(struct kernfs_node *kn);
153 int kernfs_add_one(struct kernfs_node *kn);
154 struct 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 */
162 extern const struct file_operations kernfs_file_fops;
163
164 bool kernfs_should_drain_open_files(struct kernfs_node *kn);
165 void kernfs_drain_open_files(struct kernfs_node *kn);
166
167 /*
168 * symlink.c
169 */
170 extern const struct inode_operations kernfs_symlink_iops;
171
172 /*
173 * kernfs locks
174 */
175 extern struct kernfs_global_locks *kernfs_locks;
176 #endif /* __KERNFS_INTERNAL_H */
177
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