xref: /linux/fs/kernfs/kernfs-internal.h (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
1 /*
2  * fs/kernfs/kernfs-internal.h - kernfs internal header file
3  *
4  * Copyright (c) 2001-3 Patrick Mochel
5  * Copyright (c) 2007 SUSE Linux Products GmbH
6  * Copyright (c) 2007, 2013 Tejun Heo <teheo@suse.de>
7  *
8  * This file is released under the GPLv2.
9  */
10 
11 #ifndef __KERNFS_INTERNAL_H
12 #define __KERNFS_INTERNAL_H
13 
14 #include <linux/lockdep.h>
15 #include <linux/fs.h>
16 #include <linux/mutex.h>
17 #include <linux/xattr.h>
18 
19 #include <linux/kernfs.h>
20 
21 struct kernfs_iattrs {
22 	struct iattr		ia_iattr;
23 	void			*ia_secdata;
24 	u32			ia_secdata_len;
25 
26 	struct simple_xattrs	xattrs;
27 };
28 
29 /* +1 to avoid triggering overflow warning when negating it */
30 #define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
31 
32 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
33 
34 /**
35  * kernfs_root - find out the kernfs_root a kernfs_node belongs to
36  * @kn: kernfs_node of interest
37  *
38  * Return the kernfs_root @kn belongs to.
39  */
40 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
41 {
42 	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
43 	if (kn->parent)
44 		kn = kn->parent;
45 	return kn->dir.root;
46 }
47 
48 /*
49  * mount.c
50  */
51 struct kernfs_super_info {
52 	struct super_block	*sb;
53 
54 	/*
55 	 * The root associated with this super_block.  Each super_block is
56 	 * identified by the root and ns it's associated with.
57 	 */
58 	struct kernfs_root	*root;
59 
60 	/*
61 	 * Each sb is associated with one namespace tag, currently the
62 	 * network namespace of the task which mounted this kernfs
63 	 * instance.  If multiple tags become necessary, make the following
64 	 * an array and compare kernfs_node tag against every entry.
65 	 */
66 	const void		*ns;
67 
68 	/* anchored at kernfs_root->supers, protected by kernfs_mutex */
69 	struct list_head	node;
70 };
71 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
72 
73 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
74 {
75 	if (d_really_is_negative(dentry))
76 		return NULL;
77 	return d_inode(dentry)->i_private;
78 }
79 
80 extern const struct super_operations kernfs_sops;
81 extern struct kmem_cache *kernfs_node_cache;
82 
83 /*
84  * inode.c
85  */
86 extern const struct xattr_handler *kernfs_xattr_handlers[];
87 void kernfs_evict_inode(struct inode *inode);
88 int kernfs_iop_permission(struct inode *inode, int mask);
89 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
90 int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
91 		       u32 request_mask, unsigned int query_flags);
92 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
93 
94 /*
95  * dir.c
96  */
97 extern struct mutex kernfs_mutex;
98 extern const struct dentry_operations kernfs_dops;
99 extern const struct file_operations kernfs_dir_fops;
100 extern const struct inode_operations kernfs_dir_iops;
101 
102 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
103 void kernfs_put_active(struct kernfs_node *kn);
104 int kernfs_add_one(struct kernfs_node *kn);
105 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
106 				    const char *name, umode_t mode,
107 				    unsigned flags);
108 struct kernfs_node *kernfs_find_and_get_node_by_ino(struct kernfs_root *root,
109 						    unsigned int ino);
110 
111 /*
112  * file.c
113  */
114 extern const struct file_operations kernfs_file_fops;
115 
116 void kernfs_drain_open_files(struct kernfs_node *kn);
117 
118 /*
119  * symlink.c
120  */
121 extern const struct inode_operations kernfs_symlink_iops;
122 
123 #endif	/* __KERNFS_INTERNAL_H */
124