xref: /linux/fs/kernfs/kernfs-internal.h (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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/xattr.h>
17 
18 #include <linux/kernfs.h>
19 #include <linux/fs_context.h>
20 
21 struct kernfs_iattrs {
22 	kuid_t			ia_uid;
23 	kgid_t			ia_gid;
24 	struct timespec64	ia_atime;
25 	struct timespec64	ia_mtime;
26 	struct timespec64	ia_ctime;
27 
28 	struct simple_xattrs	xattrs;
29 };
30 
31 /* +1 to avoid triggering overflow warning when negating it */
32 #define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
33 
34 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
35 
36 /**
37  * kernfs_root - find out the kernfs_root a kernfs_node belongs to
38  * @kn: kernfs_node of interest
39  *
40  * Return the kernfs_root @kn belongs to.
41  */
42 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
43 {
44 	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
45 	if (kn->parent)
46 		kn = kn->parent;
47 	return kn->dir.root;
48 }
49 
50 /*
51  * mount.c
52  */
53 struct kernfs_super_info {
54 	struct super_block	*sb;
55 
56 	/*
57 	 * The root associated with this super_block.  Each super_block is
58 	 * identified by the root and ns it's associated with.
59 	 */
60 	struct kernfs_root	*root;
61 
62 	/*
63 	 * Each sb is associated with one namespace tag, currently the
64 	 * network namespace of the task which mounted this kernfs
65 	 * instance.  If multiple tags become necessary, make the following
66 	 * an array and compare kernfs_node tag against every entry.
67 	 */
68 	const void		*ns;
69 
70 	/* anchored at kernfs_root->supers, protected by kernfs_mutex */
71 	struct list_head	node;
72 };
73 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
74 
75 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
76 {
77 	if (d_really_is_negative(dentry))
78 		return NULL;
79 	return d_inode(dentry)->i_private;
80 }
81 
82 extern const struct super_operations kernfs_sops;
83 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
84 
85 /*
86  * inode.c
87  */
88 extern const struct xattr_handler *kernfs_xattr_handlers[];
89 void kernfs_evict_inode(struct inode *inode);
90 int kernfs_iop_permission(struct inode *inode, int mask);
91 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
92 int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
93 		       u32 request_mask, unsigned int query_flags);
94 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
95 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
96 
97 /*
98  * dir.c
99  */
100 extern struct mutex kernfs_mutex;
101 extern const struct dentry_operations kernfs_dops;
102 extern const struct file_operations kernfs_dir_fops;
103 extern const struct inode_operations kernfs_dir_iops;
104 
105 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
106 void kernfs_put_active(struct kernfs_node *kn);
107 int kernfs_add_one(struct kernfs_node *kn);
108 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
109 				    const char *name, umode_t mode,
110 				    kuid_t uid, kgid_t gid,
111 				    unsigned flags);
112 struct kernfs_node *kernfs_find_and_get_node_by_ino(struct kernfs_root *root,
113 						    unsigned int ino);
114 
115 /*
116  * file.c
117  */
118 extern const struct file_operations kernfs_file_fops;
119 
120 void kernfs_drain_open_files(struct kernfs_node *kn);
121 
122 /*
123  * symlink.c
124  */
125 extern const struct inode_operations kernfs_symlink_iops;
126 
127 #endif	/* __KERNFS_INTERNAL_H */
128