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>
18 struct vm_area_struct;
22 struct sysfs_open_file {
23 /* published fields */
24 struct sysfs_dirent *sd;
27 /* private fields, do not use outside kernfs proper */
30 struct list_head list;
33 const struct vm_operations_struct *vm_ops;
38 * Read is handled by either seq_file or raw_read().
40 * If seq_show() is present, seq_file path is active. Other seq
41 * operations are optional and if not implemented, the behavior is
42 * equivalent to single_open(). @sf->private points to the
43 * associated sysfs_open_file.
45 * read() is bounced through kernel buffer and a read larger than
46 * PAGE_SIZE results in partial operation of PAGE_SIZE.
48 int (*seq_show)(struct seq_file *sf, void *v);
50 void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
51 void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
52 void (*seq_stop)(struct seq_file *sf, void *v);
54 ssize_t (*read)(struct sysfs_open_file *of, char *buf, size_t bytes,
58 * write() is bounced through kernel buffer and a write larger than
59 * PAGE_SIZE results in partial operation of PAGE_SIZE.
61 ssize_t (*write)(struct sysfs_open_file *of, char *buf, size_t bytes,
64 int (*mmap)(struct sysfs_open_file *of, struct vm_area_struct *vma);
69 struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
70 const char *name, void *priv,
72 struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent,
74 umode_t mode, loff_t size,
75 const struct kernfs_ops *ops,
76 void *priv, const void *ns);
77 struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
79 struct sysfs_dirent *target);
80 void kernfs_remove(struct sysfs_dirent *sd);
81 int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name,
83 int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
84 const char *new_name, const void *new_ns);
85 void kernfs_enable_ns(struct sysfs_dirent *sd);
86 int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
88 #else /* CONFIG_SYSFS */
90 static inline struct sysfs_dirent *
91 kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv,
93 { return ERR_PTR(-ENOSYS); }
95 static inline struct sysfs_dirent *
96 kernfs_create_file_ns(struct sysfs_dirent *parent, const char *name,
97 umode_t mode, loff_t size, const struct kernfs_ops *ops,
98 void *priv, const void *ns)
99 { return ERR_PTR(-ENOSYS); }
101 static inline struct sysfs_dirent *
102 kernfs_create_link(struct sysfs_dirent *parent, const char *name,
103 struct sysfs_dirent *target)
104 { return ERR_PTR(-ENOSYS); }
106 static inline void kernfs_remove(struct sysfs_dirent *sd) { }
108 static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,
109 const char *name, const void *ns)
112 static inline int kernfs_rename_ns(struct sysfs_dirent *sd,
113 struct sysfs_dirent *new_parent,
114 const char *new_name, const void *new_ns)
117 static inline void kernfs_enable_ns(struct sysfs_dirent *sd) { }
119 static inline int kernfs_setattr(struct sysfs_dirent *sd,
120 const struct iattr *iattr)
123 #endif /* CONFIG_SYSFS */
125 static inline struct sysfs_dirent *
126 kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv)
128 return kernfs_create_dir_ns(parent, name, priv, NULL);
131 static inline struct sysfs_dirent *
132 kernfs_create_file(struct sysfs_dirent *parent, const char *name, umode_t mode,
133 loff_t size, const struct kernfs_ops *ops, void *priv)
135 return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
138 static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
141 return kernfs_remove_by_name_ns(parent, name, NULL);
144 #endif /* __LINUX_KERNFS_H */