1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * configfs_internal.h - Internal stuff for configfs
4 *
5 * Based on sysfs:
6 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
7 *
8 * configfs Copyright (C) 2005 Oracle. All rights reserved.
9 */
10
11 #ifdef pr_fmt
12 #undef pr_fmt
13 #endif
14
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17 #include <linux/slab.h>
18 #include <linux/list.h>
19 #include <linux/spinlock.h>
20
21 struct configfs_fragment {
22 atomic_t frag_count;
23 struct rw_semaphore frag_sem;
24 bool frag_dead;
25 };
26
27 void put_fragment(struct configfs_fragment *);
28 struct configfs_fragment *get_fragment(struct configfs_fragment *);
29
30 struct configfs_dirent {
31 atomic_t s_count;
32 int s_dependent_count;
33 struct list_head s_sibling;
34 struct list_head s_children;
35 int s_links;
36 void * s_element;
37 int s_type;
38 umode_t s_mode;
39 struct dentry * s_dentry;
40 struct iattr * s_iattr;
41 #ifdef CONFIG_LOCKDEP
42 int s_depth;
43 #endif
44 struct configfs_fragment *s_frag;
45 };
46
47 #define CONFIGFS_ROOT 0x0001
48 #define CONFIGFS_DIR 0x0002
49 #define CONFIGFS_ITEM_ATTR 0x0004
50 #define CONFIGFS_ITEM_BIN_ATTR 0x0008
51 #define CONFIGFS_ITEM_LINK 0x0020
52 #define CONFIGFS_USET_DIR 0x0040
53 #define CONFIGFS_USET_DEFAULT 0x0080
54 #define CONFIGFS_USET_DROPPING 0x0100
55 #define CONFIGFS_USET_IN_MKDIR 0x0200
56 #define CONFIGFS_USET_CREATING 0x0400
57 #define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
58
59 extern struct mutex configfs_symlink_mutex;
60 extern spinlock_t configfs_dirent_lock;
61
62 extern struct kmem_cache *configfs_dir_cachep;
63
64 extern int configfs_is_root(struct config_item *item);
65
66 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
67 extern struct inode *configfs_create(struct dentry *, umode_t mode);
68
69 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
70 extern int configfs_create_bin_file(struct config_item *,
71 const struct configfs_bin_attribute *);
72 extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
73 void *, umode_t, int, struct configfs_fragment *);
74 extern int configfs_dirent_is_ready(struct configfs_dirent *);
75
76 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
77
78 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
79 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
80 extern int configfs_setattr(struct user_namespace *mnt_userns,
81 struct dentry *dentry, struct iattr *iattr);
82
83 extern struct dentry *configfs_pin_fs(void);
84 extern void configfs_release_fs(void);
85
86 extern const struct file_operations configfs_dir_operations;
87 extern const struct file_operations configfs_file_operations;
88 extern const struct file_operations configfs_bin_file_operations;
89 extern const struct inode_operations configfs_dir_inode_operations;
90 extern const struct inode_operations configfs_root_inode_operations;
91 extern const struct inode_operations configfs_symlink_inode_operations;
92 extern const struct dentry_operations configfs_dentry_ops;
93
94 extern int configfs_symlink(struct user_namespace *mnt_userns,
95 struct inode *dir, struct dentry *dentry,
96 const char *symname);
97 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
98
99 int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
100 struct dentry *dentry, char *body);
101
to_item(struct dentry * dentry)102 static inline struct config_item * to_item(struct dentry * dentry)
103 {
104 struct configfs_dirent * sd = dentry->d_fsdata;
105 return ((struct config_item *) sd->s_element);
106 }
107
to_attr(struct dentry * dentry)108 static inline struct configfs_attribute * to_attr(struct dentry * dentry)
109 {
110 struct configfs_dirent * sd = dentry->d_fsdata;
111 return ((struct configfs_attribute *) sd->s_element);
112 }
113
to_bin_attr(struct dentry * dentry)114 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
115 {
116 struct configfs_attribute *attr = to_attr(dentry);
117
118 return container_of(attr, struct configfs_bin_attribute, cb_attr);
119 }
120
configfs_get_config_item(struct dentry * dentry)121 static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
122 {
123 struct config_item * item = NULL;
124
125 spin_lock(&dentry->d_lock);
126 if (!d_unhashed(dentry)) {
127 struct configfs_dirent * sd = dentry->d_fsdata;
128 item = config_item_get(sd->s_element);
129 }
130 spin_unlock(&dentry->d_lock);
131
132 return item;
133 }
134
release_configfs_dirent(struct configfs_dirent * sd)135 static inline void release_configfs_dirent(struct configfs_dirent * sd)
136 {
137 if (!(sd->s_type & CONFIGFS_ROOT)) {
138 kfree(sd->s_iattr);
139 put_fragment(sd->s_frag);
140 kmem_cache_free(configfs_dir_cachep, sd);
141 }
142 }
143
configfs_get(struct configfs_dirent * sd)144 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
145 {
146 if (sd) {
147 WARN_ON(!atomic_read(&sd->s_count));
148 atomic_inc(&sd->s_count);
149 }
150 return sd;
151 }
152
configfs_put(struct configfs_dirent * sd)153 static inline void configfs_put(struct configfs_dirent * sd)
154 {
155 WARN_ON(!atomic_read(&sd->s_count));
156 if (atomic_dec_and_test(&sd->s_count))
157 release_configfs_dirent(sd);
158 }
159
160