2 * kernfs.h - pseudo filesystem decoupled from vfs locking
4 * This file is released under the GPLv2.
7 #ifndef __LINUX_KERNFS_H
8 #define __LINUX_KERNFS_H
10 #include <linux/kernel.h>
11 #include <linux/err.h>
12 #include <linux/list.h>
13 #include <linux/mutex.h>
14 #include <linux/lockdep.h>
19 struct vm_area_struct;
23 struct sysfs_open_file {
24 /* published fields */
25 struct sysfs_dirent *sd;
28 /* private fields, do not use outside kernfs proper */
31 struct list_head list;
34 const struct vm_operations_struct *vm_ops;
39 * Read is handled by either seq_file or raw_read().
41 * If seq_show() is present, seq_file path is active. Other seq
42 * operations are optional and if not implemented, the behavior is
43 * equivalent to single_open(). @sf->private points to the
44 * associated sysfs_open_file.
46 * read() is bounced through kernel buffer and a read larger than
47 * PAGE_SIZE results in partial operation of PAGE_SIZE.
49 int (*seq_show)(struct seq_file *sf, void *v);
51 void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
52 void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
53 void (*seq_stop)(struct seq_file *sf, void *v);
55 ssize_t (*read)(struct sysfs_open_file *of, char *buf, size_t bytes,
59 * write() is bounced through kernel buffer and a write larger than
60 * PAGE_SIZE results in partial operation of PAGE_SIZE.
62 ssize_t (*write)(struct sysfs_open_file *of, char *buf, size_t bytes,
65 int (*mmap)(struct sysfs_open_file *of, struct vm_area_struct *vma);
67 #ifdef CONFIG_DEBUG_LOCK_ALLOC
68 struct lock_class_key lockdep_key;
74 struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
75 const char *name, void *priv,
77 struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent,
79 umode_t mode, loff_t size,
80 const struct kernfs_ops *ops,
81 void *priv, const void *ns,
82 struct lock_class_key *key);
83 struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
85 struct sysfs_dirent *target);
86 void kernfs_remove(struct sysfs_dirent *sd);
87 int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name,
89 int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
90 const char *new_name, const void *new_ns);
91 void kernfs_enable_ns(struct sysfs_dirent *sd);
92 int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
93 void kernfs_notify(struct sysfs_dirent *sd);
95 #else /* CONFIG_SYSFS */
97 static inline struct sysfs_dirent *
98 kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv,
100 { return ERR_PTR(-ENOSYS); }
102 static inline struct sysfs_dirent *
103 kernfs_create_file_ns_key(struct sysfs_dirent *parent, const char *name,
104 umode_t mode, loff_t size,
105 const struct kernfs_ops *ops, void *priv,
106 const void *ns, struct lock_class_key *key)
107 { return ERR_PTR(-ENOSYS); }
109 static inline struct sysfs_dirent *
110 kernfs_create_link(struct sysfs_dirent *parent, const char *name,
111 struct sysfs_dirent *target)
112 { return ERR_PTR(-ENOSYS); }
114 static inline void kernfs_remove(struct sysfs_dirent *sd) { }
116 static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,
117 const char *name, const void *ns)
120 static inline int kernfs_rename_ns(struct sysfs_dirent *sd,
121 struct sysfs_dirent *new_parent,
122 const char *new_name, const void *new_ns)
125 static inline void kernfs_enable_ns(struct sysfs_dirent *sd) { }
127 static inline int kernfs_setattr(struct sysfs_dirent *sd,
128 const struct iattr *iattr)
131 static inline void kernfs_notify(struct sysfs_dirent *sd) { }
133 #endif /* CONFIG_SYSFS */
135 static inline struct sysfs_dirent *
136 kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv)
138 return kernfs_create_dir_ns(parent, name, priv, NULL);
141 static inline struct sysfs_dirent *
142 kernfs_create_file_ns(struct sysfs_dirent *parent, const char *name,
143 umode_t mode, loff_t size, const struct kernfs_ops *ops,
144 void *priv, const void *ns)
146 struct lock_class_key *key = NULL;
148 #ifdef CONFIG_DEBUG_LOCK_ALLOC
149 key = (struct lock_class_key *)&ops->lockdep_key;
151 return kernfs_create_file_ns_key(parent, name, mode, size, ops, priv,
155 static inline struct sysfs_dirent *
156 kernfs_create_file(struct sysfs_dirent *parent, const char *name, umode_t mode,
157 loff_t size, const struct kernfs_ops *ops, void *priv)
159 return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
162 static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
165 return kernfs_remove_by_name_ns(parent, name, NULL);
168 #endif /* __LINUX_KERNFS_H */