xref: /openbmc/linux/fs/kernfs/kernfs-internal.h (revision 023e41632e065d49bcbe31b3c4b336217f96a271)
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 #include <linux/fs_context.h>
21 
22 struct kernfs_iattrs {
23 	struct iattr		ia_iattr;
24 	void			*ia_secdata;
25 	u32			ia_secdata_len;
26 
27 	struct simple_xattrs	xattrs;
28 };
29 
30 /* +1 to avoid triggering overflow warning when negating it */
31 #define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
32 
33 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
34 
35 /**
36  * kernfs_root - find out the kernfs_root a kernfs_node belongs to
37  * @kn: kernfs_node of interest
38  *
39  * Return the kernfs_root @kn belongs to.
40  */
41 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
42 {
43 	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
44 	if (kn->parent)
45 		kn = kn->parent;
46 	return kn->dir.root;
47 }
48 
49 /*
50  * mount.c
51  */
52 struct kernfs_super_info {
53 	struct super_block	*sb;
54 
55 	/*
56 	 * The root associated with this super_block.  Each super_block is
57 	 * identified by the root and ns it's associated with.
58 	 */
59 	struct kernfs_root	*root;
60 
61 	/*
62 	 * Each sb is associated with one namespace tag, currently the
63 	 * network namespace of the task which mounted this kernfs
64 	 * instance.  If multiple tags become necessary, make the following
65 	 * an array and compare kernfs_node tag against every entry.
66 	 */
67 	const void		*ns;
68 
69 	/* anchored at kernfs_root->supers, protected by kernfs_mutex */
70 	struct list_head	node;
71 };
72 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
73 
74 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
75 {
76 	if (d_really_is_negative(dentry))
77 		return NULL;
78 	return d_inode(dentry)->i_private;
79 }
80 
81 extern const struct super_operations kernfs_sops;
82 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
83 
84 /*
85  * inode.c
86  */
87 extern const struct xattr_handler *kernfs_xattr_handlers[];
88 void kernfs_evict_inode(struct inode *inode);
89 int kernfs_iop_permission(struct inode *inode, int mask);
90 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
91 int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
92 		       u32 request_mask, unsigned int query_flags);
93 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
94 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
95 
96 /*
97  * dir.c
98  */
99 extern struct mutex kernfs_mutex;
100 extern const struct dentry_operations kernfs_dops;
101 extern const struct file_operations kernfs_dir_fops;
102 extern const struct inode_operations kernfs_dir_iops;
103 
104 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
105 void kernfs_put_active(struct kernfs_node *kn);
106 int kernfs_add_one(struct kernfs_node *kn);
107 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
108 				    const char *name, umode_t mode,
109 				    kuid_t uid, kgid_t gid,
110 				    unsigned flags);
111 struct kernfs_node *kernfs_find_and_get_node_by_ino(struct kernfs_root *root,
112 						    unsigned int ino);
113 
114 /*
115  * file.c
116  */
117 extern const struct file_operations kernfs_file_fops;
118 
119 void kernfs_drain_open_files(struct kernfs_node *kn);
120 
121 /*
122  * symlink.c
123  */
124 extern const struct inode_operations kernfs_symlink_iops;
125 
126 #endif	/* __KERNFS_INTERNAL_H */
127