xref: /linux/fs/kernfs/kernfs-internal.h (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
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 	atomic_t		nr_user_xattrs;
30 	atomic_t		user_xattr_size;
31 };
32 
33 /* +1 to avoid triggering overflow warning when negating it */
34 #define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
35 
36 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
37 
38 /**
39  * kernfs_root - find out the kernfs_root a kernfs_node belongs to
40  * @kn: kernfs_node of interest
41  *
42  * Return the kernfs_root @kn belongs to.
43  */
44 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
45 {
46 	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
47 	if (kn->parent)
48 		kn = kn->parent;
49 	return kn->dir.root;
50 }
51 
52 /*
53  * mount.c
54  */
55 struct kernfs_super_info {
56 	struct super_block	*sb;
57 
58 	/*
59 	 * The root associated with this super_block.  Each super_block is
60 	 * identified by the root and ns it's associated with.
61 	 */
62 	struct kernfs_root	*root;
63 
64 	/*
65 	 * Each sb is associated with one namespace tag, currently the
66 	 * network namespace of the task which mounted this kernfs
67 	 * instance.  If multiple tags become necessary, make the following
68 	 * an array and compare kernfs_node tag against every entry.
69 	 */
70 	const void		*ns;
71 
72 	/* anchored at kernfs_root->supers, protected by kernfs_mutex */
73 	struct list_head	node;
74 };
75 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
76 
77 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
78 {
79 	if (d_really_is_negative(dentry))
80 		return NULL;
81 	return d_inode(dentry)->i_private;
82 }
83 
84 extern const struct super_operations kernfs_sops;
85 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
86 
87 /*
88  * inode.c
89  */
90 extern const struct xattr_handler *kernfs_xattr_handlers[];
91 void kernfs_evict_inode(struct inode *inode);
92 int kernfs_iop_permission(struct user_namespace *mnt_userns,
93 			  struct inode *inode, int mask);
94 int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
95 		       struct iattr *iattr);
96 int kernfs_iop_getattr(struct user_namespace *mnt_userns,
97 		       const struct path *path, struct kstat *stat,
98 		       u32 request_mask, unsigned int query_flags);
99 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
100 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
101 
102 /*
103  * dir.c
104  */
105 extern struct mutex kernfs_mutex;
106 extern const struct dentry_operations kernfs_dops;
107 extern const struct file_operations kernfs_dir_fops;
108 extern const struct inode_operations kernfs_dir_iops;
109 
110 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
111 void kernfs_put_active(struct kernfs_node *kn);
112 int kernfs_add_one(struct kernfs_node *kn);
113 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
114 				    const char *name, umode_t mode,
115 				    kuid_t uid, kgid_t gid,
116 				    unsigned flags);
117 
118 /*
119  * file.c
120  */
121 extern const struct file_operations kernfs_file_fops;
122 
123 void kernfs_drain_open_files(struct kernfs_node *kn);
124 
125 /*
126  * symlink.c
127  */
128 extern const struct inode_operations kernfs_symlink_iops;
129 
130 #endif	/* __KERNFS_INTERNAL_H */
131