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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
23struct configfs_fragment {
24 atomic_t frag_count;
25 struct rw_semaphore frag_sem;
26 bool frag_dead;
27};
28
29void put_fragment(struct configfs_fragment *);
30struct configfs_fragment *get_fragment(struct configfs_fragment *);
31
32struct 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
61extern struct mutex configfs_symlink_mutex;
62extern spinlock_t configfs_dirent_lock;
63
64extern struct kmem_cache *configfs_dir_cachep;
65
66extern int configfs_is_root(struct config_item *item);
67
68extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
69extern struct inode *configfs_create(struct dentry *, umode_t mode);
70
71extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
72extern int configfs_create_bin_file(struct config_item *,
73 const struct configfs_bin_attribute *);
74extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
75 void *, umode_t, int, struct configfs_fragment *);
76extern int configfs_dirent_is_ready(struct configfs_dirent *);
77
78extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
79
80extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
81extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
82extern int configfs_setattr(struct user_namespace *mnt_userns,
83 struct dentry *dentry, struct iattr *iattr);
84
85extern struct dentry *configfs_pin_fs(void);
86extern void configfs_release_fs(void);
87
88extern const struct file_operations configfs_dir_operations;
89extern const struct file_operations configfs_file_operations;
90extern const struct file_operations configfs_bin_file_operations;
91extern const struct inode_operations configfs_dir_inode_operations;
92extern const struct inode_operations configfs_root_inode_operations;
93extern const struct inode_operations configfs_symlink_inode_operations;
94extern const struct dentry_operations configfs_dentry_ops;
95
96extern int configfs_symlink(struct user_namespace *mnt_userns,
97 struct inode *dir, struct dentry *dentry,
98 const char *symname);
99extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
100
101int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
102 struct dentry *dentry, char *body);
103
104static inline struct config_item * to_item(struct dentry * dentry)
105{
106 struct configfs_dirent * sd = dentry->d_fsdata;
107 return ((struct config_item *) sd->s_element);
108}
109
110static inline struct configfs_attribute * to_attr(struct dentry * dentry)
111{
112 struct configfs_dirent * sd = dentry->d_fsdata;
113 return ((struct configfs_attribute *) sd->s_element);
114}
115
116static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
117{
118 struct configfs_attribute *attr = to_attr(dentry);
119
120 return container_of(attr, struct configfs_bin_attribute, cb_attr);
121}
122
123static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
124{
125 struct config_item * item = NULL;
126
127 spin_lock(&dentry->d_lock);
128 if (!d_unhashed(dentry)) {
129 struct configfs_dirent * sd = dentry->d_fsdata;
130 item = config_item_get(sd->s_element);
131 }
132 spin_unlock(&dentry->d_lock);
133
134 return item;
135}
136
137static inline void release_configfs_dirent(struct configfs_dirent * sd)
138{
139 if (!(sd->s_type & CONFIGFS_ROOT)) {
140 kfree(sd->s_iattr);
141 put_fragment(sd->s_frag);
142 kmem_cache_free(configfs_dir_cachep, sd);
143 }
144}
145
146static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
147{
148 if (sd) {
149 WARN_ON(!atomic_read(&sd->s_count));
150 atomic_inc(&sd->s_count);
151 }
152 return sd;
153}
154
155static inline void configfs_put(struct configfs_dirent * sd)
156{
157 WARN_ON(!atomic_read(&sd->s_count));
158 if (atomic_dec_and_test(&sd->s_count))
159 release_configfs_dirent(sd);
160}
161
162