xref: /openbmc/linux/fs/configfs/configfs_internal.h (revision 9a87ffc99ec8eb8d35eed7c4f816d75f5cc9662e)
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 mnt_idmap *idmap,
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 mnt_idmap *idmap,
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