xref: /openbmc/linux/fs/kernfs/kernfs-internal.h (revision 151f4e2b)
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 	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 };
31 
32 /* +1 to avoid triggering overflow warning when negating it */
33 #define KN_DEACTIVATED_BIAS		(INT_MIN + 1)
34 
35 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
36 
37 /**
38  * kernfs_root - find out the kernfs_root a kernfs_node belongs to
39  * @kn: kernfs_node of interest
40  *
41  * Return the kernfs_root @kn belongs to.
42  */
43 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
44 {
45 	/* if parent exists, it's always a dir; otherwise, @sd is a dir */
46 	if (kn->parent)
47 		kn = kn->parent;
48 	return kn->dir.root;
49 }
50 
51 /*
52  * mount.c
53  */
54 struct kernfs_super_info {
55 	struct super_block	*sb;
56 
57 	/*
58 	 * The root associated with this super_block.  Each super_block is
59 	 * identified by the root and ns it's associated with.
60 	 */
61 	struct kernfs_root	*root;
62 
63 	/*
64 	 * Each sb is associated with one namespace tag, currently the
65 	 * network namespace of the task which mounted this kernfs
66 	 * instance.  If multiple tags become necessary, make the following
67 	 * an array and compare kernfs_node tag against every entry.
68 	 */
69 	const void		*ns;
70 
71 	/* anchored at kernfs_root->supers, protected by kernfs_mutex */
72 	struct list_head	node;
73 };
74 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
75 
76 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
77 {
78 	if (d_really_is_negative(dentry))
79 		return NULL;
80 	return d_inode(dentry)->i_private;
81 }
82 
83 extern const struct super_operations kernfs_sops;
84 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
85 
86 /*
87  * inode.c
88  */
89 extern const struct xattr_handler *kernfs_xattr_handlers[];
90 void kernfs_evict_inode(struct inode *inode);
91 int kernfs_iop_permission(struct inode *inode, int mask);
92 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
93 int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
94 		       u32 request_mask, unsigned int query_flags);
95 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
96 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
97 
98 /*
99  * dir.c
100  */
101 extern struct mutex kernfs_mutex;
102 extern const struct dentry_operations kernfs_dops;
103 extern const struct file_operations kernfs_dir_fops;
104 extern const struct inode_operations kernfs_dir_iops;
105 
106 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
107 void kernfs_put_active(struct kernfs_node *kn);
108 int kernfs_add_one(struct kernfs_node *kn);
109 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
110 				    const char *name, umode_t mode,
111 				    kuid_t uid, kgid_t gid,
112 				    unsigned flags);
113 struct kernfs_node *kernfs_find_and_get_node_by_ino(struct kernfs_root *root,
114 						    unsigned int ino);
115 
116 /*
117  * file.c
118  */
119 extern const struct file_operations kernfs_file_fops;
120 
121 void kernfs_drain_open_files(struct kernfs_node *kn);
122 
123 /*
124  * symlink.c
125  */
126 extern const struct inode_operations kernfs_symlink_iops;
127 
128 #endif	/* __KERNFS_INTERNAL_H */
129