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
37struct configfs_dirent {
38	atomic_t		s_count;
39	int			s_dependent_count;
40	struct list_head	s_sibling;
41	struct list_head	s_children;
42	struct list_head	s_links;
43	void			* s_element;
44	int			s_type;
45	umode_t			s_mode;
46	struct dentry		* s_dentry;
47	struct iattr		* s_iattr;
48#ifdef CONFIG_LOCKDEP
49	int			s_depth;
50#endif
51};
52
53#define CONFIGFS_ROOT		0x0001
54#define CONFIGFS_DIR		0x0002
55#define CONFIGFS_ITEM_ATTR	0x0004
56#define CONFIGFS_ITEM_LINK	0x0020
57#define CONFIGFS_USET_DIR	0x0040
58#define CONFIGFS_USET_DEFAULT	0x0080
59#define CONFIGFS_USET_DROPPING	0x0100
60#define CONFIGFS_USET_IN_MKDIR	0x0200
61#define CONFIGFS_USET_CREATING	0x0400
62#define CONFIGFS_NOT_PINNED	(CONFIGFS_ITEM_ATTR)
63
64extern struct mutex configfs_symlink_mutex;
65extern spinlock_t configfs_dirent_lock;
66
67extern struct kmem_cache *configfs_dir_cachep;
68
69extern int configfs_is_root(struct config_item *item);
70
71extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
72extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
73
74extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
75extern int configfs_make_dirent(struct configfs_dirent *,
76				struct dentry *, void *, umode_t, int);
77extern int configfs_dirent_is_ready(struct configfs_dirent *);
78
79extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
80
81extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
82extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
83extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr);
84
85extern struct dentry *configfs_pin_fs(void);
86extern void configfs_release_fs(void);
87
88extern struct rw_semaphore configfs_rename_sem;
89extern const struct file_operations configfs_dir_operations;
90extern const struct file_operations configfs_file_operations;
91extern const struct file_operations bin_fops;
92extern const struct inode_operations configfs_dir_inode_operations;
93extern const struct inode_operations configfs_root_inode_operations;
94extern const struct inode_operations configfs_symlink_inode_operations;
95extern const struct dentry_operations configfs_dentry_ops;
96
97extern int configfs_symlink(struct inode *dir, struct dentry *dentry,
98			    const char *symname);
99extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
100
101struct configfs_symlink {
102	struct list_head sl_list;
103	struct config_item *sl_target;
104};
105
106extern int configfs_create_link(struct configfs_symlink *sl,
107				struct dentry *parent,
108				struct dentry *dentry);
109
110static inline struct config_item * to_item(struct dentry * dentry)
111{
112	struct configfs_dirent * sd = dentry->d_fsdata;
113	return ((struct config_item *) sd->s_element);
114}
115
116static inline struct configfs_attribute * to_attr(struct dentry * dentry)
117{
118	struct configfs_dirent * sd = dentry->d_fsdata;
119	return ((struct configfs_attribute *) sd->s_element);
120}
121
122static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
123{
124	struct config_item * item = NULL;
125
126	spin_lock(&dentry->d_lock);
127	if (!d_unhashed(dentry)) {
128		struct configfs_dirent * sd = dentry->d_fsdata;
129		if (sd->s_type & CONFIGFS_ITEM_LINK) {
130			struct configfs_symlink * sl = sd->s_element;
131			item = config_item_get(sl->sl_target);
132		} else
133			item = config_item_get(sd->s_element);
134	}
135	spin_unlock(&dentry->d_lock);
136
137	return item;
138}
139
140static inline void release_configfs_dirent(struct configfs_dirent * sd)
141{
142	if (!(sd->s_type & CONFIGFS_ROOT)) {
143		kfree(sd->s_iattr);
144		kmem_cache_free(configfs_dir_cachep, sd);
145	}
146}
147
148static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
149{
150	if (sd) {
151		WARN_ON(!atomic_read(&sd->s_count));
152		atomic_inc(&sd->s_count);
153	}
154	return sd;
155}
156
157static inline void configfs_put(struct configfs_dirent * sd)
158{
159	WARN_ON(!atomic_read(&sd->s_count));
160	if (atomic_dec_and_test(&sd->s_count))
161		release_configfs_dirent(sd);
162}
163
164