1 /* -*- mode: c; c-basic-offset:8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * configfs_internal.h - Internal stuff for configfs
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
20 *
21 * Based on sysfs:
22 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
23 *
24 * configfs Copyright (C) 2005 Oracle. All rights reserved.
25 */
26
27 #ifdef pr_fmt
28 #undef pr_fmt
29 #endif
30
31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33 #include <linux/slab.h>
34 #include <linux/list.h>
35 #include <linux/spinlock.h>
36
37 struct configfs_fragment {
38 atomic_t frag_count;
39 struct rw_semaphore frag_sem;
40 bool frag_dead;
41 };
42
43 void put_fragment(struct configfs_fragment *);
44 struct configfs_fragment *get_fragment(struct configfs_fragment *);
45
46 struct configfs_dirent {
47 atomic_t s_count;
48 int s_dependent_count;
49 struct list_head s_sibling;
50 struct list_head s_children;
51 struct list_head s_links;
52 void * s_element;
53 int s_type;
54 umode_t s_mode;
55 struct dentry * s_dentry;
56 struct iattr * s_iattr;
57 #ifdef CONFIG_LOCKDEP
58 int s_depth;
59 #endif
60 struct configfs_fragment *s_frag;
61 };
62
63 #define CONFIGFS_ROOT 0x0001
64 #define CONFIGFS_DIR 0x0002
65 #define CONFIGFS_ITEM_ATTR 0x0004
66 #define CONFIGFS_ITEM_BIN_ATTR 0x0008
67 #define CONFIGFS_ITEM_LINK 0x0020
68 #define CONFIGFS_USET_DIR 0x0040
69 #define CONFIGFS_USET_DEFAULT 0x0080
70 #define CONFIGFS_USET_DROPPING 0x0100
71 #define CONFIGFS_USET_IN_MKDIR 0x0200
72 #define CONFIGFS_USET_CREATING 0x0400
73 #define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
74
75 extern struct mutex configfs_symlink_mutex;
76 extern spinlock_t configfs_dirent_lock;
77
78 extern struct kmem_cache *configfs_dir_cachep;
79
80 extern int configfs_is_root(struct config_item *item);
81
82 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
83 extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
84
85 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
86 extern int configfs_create_bin_file(struct config_item *,
87 const struct configfs_bin_attribute *);
88 extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
89 void *, umode_t, int, struct configfs_fragment *);
90 extern int configfs_dirent_is_ready(struct configfs_dirent *);
91
92 extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
93
94 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
95 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
96 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
97
98 extern struct dentry *configfs_pin_fs(void);
99 extern void configfs_release_fs(void);
100
101 extern struct rw_semaphore configfs_rename_sem;
102 extern const struct file_operations configfs_dir_operations;
103 extern const struct file_operations configfs_file_operations;
104 extern const struct file_operations configfs_bin_file_operations;
105 extern const struct inode_operations configfs_dir_inode_operations;
106 extern const struct inode_operations configfs_root_inode_operations;
107 extern const struct inode_operations configfs_symlink_inode_operations;
108 extern const struct dentry_operations configfs_dentry_ops;
109
110 extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
111 const char *symname);
112 extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
113
114 struct configfs_symlink {
115 struct list_head sl_list;
116 struct config_item *sl_target;
117 };
118
119 extern int configfs_create_link(struct configfs_symlink *sl,
120 struct dentry *parent,
121 struct dentry *dentry);
122
to_item(struct dentry * dentry)123 static inline struct config_item * to_item(struct dentry * dentry)
124 {
125 struct configfs_dirent * sd = dentry->d_fsdata;
126 return ((struct config_item *) sd->s_element);
127 }
128
to_attr(struct dentry * dentry)129 static inline struct configfs_attribute * to_attr(struct dentry * dentry)
130 {
131 struct configfs_dirent * sd = dentry->d_fsdata;
132 return ((struct configfs_attribute *) sd->s_element);
133 }
134
to_bin_attr(struct dentry * dentry)135 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
136 {
137 struct configfs_attribute *attr = to_attr(dentry);
138
139 return container_of(attr, struct configfs_bin_attribute, cb_attr);
140 }
141
configfs_get_config_item(struct dentry * dentry)142 static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
143 {
144 struct config_item * item = NULL;
145
146 spin_lock(&dentry->d_lock);
147 if (!d_unhashed(dentry)) {
148 struct configfs_dirent * sd = dentry->d_fsdata;
149 if (sd->s_type & CONFIGFS_ITEM_LINK) {
150 struct configfs_symlink * sl = sd->s_element;
151 item = config_item_get(sl->sl_target);
152 } else
153 item = config_item_get(sd->s_element);
154 }
155 spin_unlock(&dentry->d_lock);
156
157 return item;
158 }
159
release_configfs_dirent(struct configfs_dirent * sd)160 static inline void release_configfs_dirent(struct configfs_dirent * sd)
161 {
162 if (!(sd->s_type & CONFIGFS_ROOT)) {
163 kfree(sd->s_iattr);
164 put_fragment(sd->s_frag);
165 kmem_cache_free(configfs_dir_cachep, sd);
166 }
167 }
168
configfs_get(struct configfs_dirent * sd)169 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
170 {
171 if (sd) {
172 WARN_ON(!atomic_read(&sd->s_count));
173 atomic_inc(&sd->s_count);
174 }
175 return sd;
176 }
177
configfs_put(struct configfs_dirent * sd)178 static inline void configfs_put(struct configfs_dirent * sd)
179 {
180 WARN_ON(!atomic_read(&sd->s_count));
181 if (atomic_dec_and_test(&sd->s_count))
182 release_configfs_dirent(sd);
183 }
184
185