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
54 /* +1 to avoid triggering overflow warning when negating it */
55 #define KN_DEACTIVATED_BIAS (INT_MIN + 1)
56
57 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
58
59 /**
60 * kernfs_root - find out the kernfs_root a kernfs_node belongs to
61 * @kn: kernfs_node of interest
62 *
63 * Return: the kernfs_root @kn belongs to.
64 */
kernfs_root(struct kernfs_node * kn)65 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
66 {
67 /* if parent exists, it's always a dir; otherwise, @sd is a dir */
68 if (kn->parent)
69 kn = kn->parent;
70 return kn->dir.root;
71 }
72
73 /*
74 * mount.c
75 */
76 struct kernfs_super_info {
77 struct super_block *sb;
78
79 /*
80 * The root associated with this super_block. Each super_block is
81 * identified by the root and ns it's associated with.
82 */
83 struct kernfs_root *root;
84
85 /*
86 * Each sb is associated with one namespace tag, currently the
87 * network namespace of the task which mounted this kernfs
88 * instance. If multiple tags become necessary, make the following
89 * an array and compare kernfs_node tag against every entry.
90 */
91 const void *ns;
92
93 /* anchored at kernfs_root->supers, protected by kernfs_rwsem */
94 struct list_head node;
95 };
96 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
97
kernfs_dentry_node(struct dentry * dentry)98 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
99 {
100 if (d_really_is_negative(dentry))
101 return NULL;
102 return d_inode(dentry)->i_private;
103 }
104
kernfs_set_rev(struct kernfs_node * parent,struct dentry * dentry)105 static inline void kernfs_set_rev(struct kernfs_node *parent,
106 struct dentry *dentry)
107 {
108 dentry->d_time = parent->dir.rev;
109 }
110
kernfs_inc_rev(struct kernfs_node * parent)111 static inline void kernfs_inc_rev(struct kernfs_node *parent)
112 {
113 parent->dir.rev++;
114 }
115
kernfs_dir_changed(struct kernfs_node * parent,struct dentry * dentry)116 static inline bool kernfs_dir_changed(struct kernfs_node *parent,
117 struct dentry *dentry)
118 {
119 if (parent->dir.rev != dentry->d_time)
120 return true;
121 return false;
122 }
123
124 extern const struct super_operations kernfs_sops;
125 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
126
127 /*
128 * inode.c
129 */
130 extern const struct xattr_handler *kernfs_xattr_handlers[];
131 void kernfs_evict_inode(struct inode *inode);
132 int kernfs_iop_permission(struct mnt_idmap *idmap,
133 struct inode *inode, int mask);
134 int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
135 struct iattr *iattr);
136 int kernfs_iop_getattr(struct mnt_idmap *idmap,
137 const struct path *path, struct kstat *stat,
138 u32 request_mask, unsigned int query_flags);
139 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
140 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
141
142 /*
143 * dir.c
144 */
145 extern const struct dentry_operations kernfs_dops;
146 extern const struct file_operations kernfs_dir_fops;
147 extern const struct inode_operations kernfs_dir_iops;
148
149 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
150 void kernfs_put_active(struct kernfs_node *kn);
151 int kernfs_add_one(struct kernfs_node *kn);
152 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
153 const char *name, umode_t mode,
154 kuid_t uid, kgid_t gid,
155 unsigned flags);
156
157 /*
158 * file.c
159 */
160 extern const struct file_operations kernfs_file_fops;
161
162 bool kernfs_should_drain_open_files(struct kernfs_node *kn);
163 void kernfs_drain_open_files(struct kernfs_node *kn);
164
165 /*
166 * symlink.c
167 */
168 extern const struct inode_operations kernfs_symlink_iops;
169
170 /*
171 * kernfs locks
172 */
173 extern struct kernfs_global_locks *kernfs_locks;
174 #endif /* __KERNFS_INTERNAL_H */
175
