1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* -*- mode: c; c-basic-offset:8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * configfs_internal.h - Internal stuff for configfs
6 *
7 * Based on sysfs:
8 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
9 *
10 * configfs Copyright (C) 2005 Oracle. All rights reserved.
11 */
12
13 #ifdef pr_fmt
14 #undef pr_fmt
15 #endif
16
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19 #include <linux/slab.h>
20 #include <linux/list.h>
21 #include <linux/spinlock.h>
22
23 struct configfs_fragment {
24 atomic_t frag_count;
25 struct rw_semaphore frag_sem;
26 bool frag_dead;
27 };
28
29 void put_fragment(struct configfs_fragment *);
30 struct configfs_fragment *get_fragment(struct configfs_fragment *);
31
32 struct configfs_dirent {
33 atomic_t s_count;
34 int s_dependent_count;
35 struct list_head s_sibling;
36 struct list_head s_children;
37 int s_links;
38 void * s_element;
39 int s_type;
40 umode_t s_mode;
41 struct dentry * s_dentry;
42 struct iattr * s_iattr;
43 #ifdef CONFIG_LOCKDEP
44 int s_depth;
45 #endif
46 struct configfs_fragment *s_frag;
47 };
48
49 #define CONFIGFS_ROOT 0x0001
50 #define CONFIGFS_DIR 0x0002
51 #define CONFIGFS_ITEM_ATTR 0x0004
52 #define CONFIGFS_ITEM_BIN_ATTR 0x0008
53 #define CONFIGFS_ITEM_LINK 0x0020
54 #define CONFIGFS_USET_DIR 0x0040
55 #define CONFIGFS_USET_DEFAULT 0x0080
56 #define CONFIGFS_USET_DROPPING 0x0100
57 #define CONFIGFS_USET_IN_MKDIR 0x0200
58 #define CONFIGFS_USET_CREATING 0x0400
59 #define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
60
61 extern struct mutex configfs_symlink_mutex;
62 extern spinlock_t configfs_dirent_lock;
63
64 extern struct kmem_cache *configfs_dir_cachep;
65
66 extern int configfs_is_root(struct config_item *item);
67
68 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
69 extern struct inode *configfs_create(struct dentry *, umode_t mode);
70
71 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
72 extern int configfs_create_bin_file(struct config_item *,
73 const struct configfs_bin_attribute *);
74 extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
75 void *, umode_t, int, struct configfs_fragment *);
76 extern int configfs_dirent_is_ready(struct configfs_dirent *);
77
78 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
79
80 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
81 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
82 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
83
84 extern struct dentry *configfs_pin_fs(void);
85 extern void configfs_release_fs(void);
86
87 extern const struct file_operations configfs_dir_operations;
88 extern const struct file_operations configfs_file_operations;
89 extern const struct file_operations configfs_bin_file_operations;
90 extern const struct inode_operations configfs_dir_inode_operations;
91 extern const struct inode_operations configfs_root_inode_operations;
92 extern const struct inode_operations configfs_symlink_inode_operations;
93 extern const struct dentry_operations configfs_dentry_ops;
94
95 extern int configfs_symlink(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