#include <linux/kernel.h>
#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+#include <linux/lockdep.h>
+#include <linux/rbtree.h>
+#include <linux/atomic.h>
+#include <linux/completion.h>
struct file;
struct iattr;
+struct seq_file;
+struct vm_area_struct;
+struct super_block;
+struct file_system_type;
-struct sysfs_dirent;
+struct kernfs_open_node;
+struct kernfs_iattrs;
+
+enum kernfs_node_type {
+ KERNFS_DIR = 0x0001,
+ KERNFS_FILE = 0x0002,
+ KERNFS_LINK = 0x0004,
+};
+
+#define KERNFS_TYPE_MASK 0x000f
+#define KERNFS_COPY_NAME (KERNFS_DIR | KERNFS_LINK)
+#define KERNFS_ACTIVE_REF KERNFS_FILE
+#define KERNFS_FLAG_MASK ~KERNFS_TYPE_MASK
+
+enum kernfs_node_flag {
+ KERNFS_REMOVED = 0x0010,
+ KERNFS_NS = 0x0020,
+ KERNFS_HAS_SEQ_SHOW = 0x0040,
+ KERNFS_HAS_MMAP = 0x0080,
+ KERNFS_LOCKDEP = 0x0100,
+};
+
+/* type-specific structures for kernfs_node union members */
+struct kernfs_elem_dir {
+ unsigned long subdirs;
+ /* children rbtree starts here and goes through kn->rb */
+ struct rb_root children;
+
+ /*
+ * The kernfs hierarchy this directory belongs to. This fits
+ * better directly in kernfs_node but is here to save space.
+ */
+ struct kernfs_root *root;
+};
+
+struct kernfs_elem_symlink {
+ struct kernfs_node *target_kn;
+};
+
+struct kernfs_elem_attr {
+ const struct kernfs_ops *ops;
+ struct kernfs_open_node *open;
+ loff_t size;
+};
+
+/*
+ * kernfs_node - the building block of kernfs hierarchy. Each and every
+ * kernfs node is represented by single kernfs_node. Most fields are
+ * private to kernfs and shouldn't be accessed directly by kernfs users.
+ *
+ * As long as s_count reference is held, the kernfs_node itself is
+ * accessible. Dereferencing elem or any other outer entity requires
+ * active reference.
+ */
+struct kernfs_node {
+ atomic_t count;
+ atomic_t active;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+ /* the following two fields are published */
+ struct kernfs_node *parent;
+ const char *name;
+
+ struct rb_node rb;
+
+ union {
+ struct completion *completion;
+ struct kernfs_node *removed_list;
+ } u;
+
+ const void *ns; /* namespace tag */
+ unsigned int hash; /* ns + name hash */
+ union {
+ struct kernfs_elem_dir dir;
+ struct kernfs_elem_symlink symlink;
+ struct kernfs_elem_attr attr;
+ };
+
+ void *priv;
+
+ unsigned short flags;
+ umode_t mode;
+ unsigned int ino;
+ struct kernfs_iattrs *iattr;
+};
+
+struct kernfs_root {
+ /* published fields */
+ struct kernfs_node *kn;
+
+ /* private fields, do not use outside kernfs proper */
+ struct ida ino_ida;
+};
+
+struct kernfs_open_file {
+ /* published fields */
+ struct kernfs_node *kn;
+ struct file *file;
+
+ /* private fields, do not use outside kernfs proper */
+ struct mutex mutex;
+ int event;
+ struct list_head list;
+
+ bool mmapped;
+ const struct vm_operations_struct *vm_ops;
+};
+
+struct kernfs_ops {
+ /*
+ * Read is handled by either seq_file or raw_read().
+ *
+ * If seq_show() is present, seq_file path is active. Other seq
+ * operations are optional and if not implemented, the behavior is
+ * equivalent to single_open(). @sf->private points to the
+ * associated kernfs_open_file.
+ *
+ * read() is bounced through kernel buffer and a read larger than
+ * PAGE_SIZE results in partial operation of PAGE_SIZE.
+ */
+ int (*seq_show)(struct seq_file *sf, void *v);
+
+ void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
+ void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
+ void (*seq_stop)(struct seq_file *sf, void *v);
+
+ ssize_t (*read)(struct kernfs_open_file *of, char *buf, size_t bytes,
+ loff_t off);
+
+ /*
+ * write() is bounced through kernel buffer and a write larger than
+ * PAGE_SIZE results in partial operation of PAGE_SIZE.
+ */
+ ssize_t (*write)(struct kernfs_open_file *of, char *buf, size_t bytes,
+ loff_t off);
+
+ int (*mmap)(struct kernfs_open_file *of, struct vm_area_struct *vma);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lock_class_key lockdep_key;
+#endif
+};
#ifdef CONFIG_SYSFS
-struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
- const char *name,
- struct sysfs_dirent *target);
-void kernfs_remove(struct sysfs_dirent *sd);
-int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name,
+static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
+{
+ return kn->flags & KERNFS_TYPE_MASK;
+}
+
+/**
+ * kernfs_enable_ns - enable namespace under a directory
+ * @kn: directory of interest, should be empty
+ *
+ * This is to be called right after @kn is created to enable namespace
+ * under it. All children of @kn must have non-NULL namespace tags and
+ * only the ones which match the super_block's tag will be visible.
+ */
+static inline void kernfs_enable_ns(struct kernfs_node *kn)
+{
+ WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
+ WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
+ kn->flags |= KERNFS_NS;
+}
+
+/**
+ * kernfs_ns_enabled - test whether namespace is enabled
+ * @kn: the node to test
+ *
+ * Test whether namespace filtering is enabled for the children of @ns.
+ */
+static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
+{
+ return kn->flags & KERNFS_NS;
+}
+
+struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
+ const char *name, const void *ns);
+void kernfs_get(struct kernfs_node *kn);
+void kernfs_put(struct kernfs_node *kn);
+
+struct kernfs_root *kernfs_create_root(void *priv);
+void kernfs_destroy_root(struct kernfs_root *root);
+
+struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
+ const char *name, void *priv,
+ const void *ns);
+struct kernfs_node *kernfs_create_file_ns_key(struct kernfs_node *parent,
+ const char *name,
+ umode_t mode, loff_t size,
+ const struct kernfs_ops *ops,
+ void *priv, const void *ns,
+ struct lock_class_key *key);
+struct kernfs_node *kernfs_create_link(struct kernfs_node *parent,
+ const char *name,
+ struct kernfs_node *target);
+void kernfs_remove(struct kernfs_node *kn);
+int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
const void *ns);
-int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
+int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
const char *new_name, const void *new_ns);
-int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
+int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
+void kernfs_notify(struct kernfs_node *kn);
+
+const void *kernfs_super_ns(struct super_block *sb);
+struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
+ struct kernfs_root *root, const void *ns);
+void kernfs_kill_sb(struct super_block *sb);
+
+void kernfs_init(void);
#else /* CONFIG_SYSFS */
-static inline struct sysfs_dirent *
-kernfs_create_link(struct sysfs_dirent *parent, const char *name,
- struct sysfs_dirent *target)
+static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
+{ return 0; } /* whatever */
+
+static inline void kernfs_enable_ns(struct kernfs_node *kn) { }
+
+static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
+{ return false; }
+
+static inline struct kernfs_node *
+kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name,
+ const void *ns)
+{ return NULL; }
+
+static inline void kernfs_get(struct kernfs_node *kn) { }
+static inline void kernfs_put(struct kernfs_node *kn) { }
+
+static inline struct kernfs_root *kernfs_create_root(void *priv)
{ return ERR_PTR(-ENOSYS); }
-static inline void kernfs_remove(struct sysfs_dirent *sd) { }
+static inline void kernfs_destroy_root(struct kernfs_root *root) { }
-static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,
+static inline struct kernfs_node *
+kernfs_create_dir_ns(struct kernfs_node *parent, const char *name, void *priv,
+ const void *ns)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline struct kernfs_node *
+kernfs_create_file_ns_key(struct kernfs_node *parent, const char *name,
+ umode_t mode, loff_t size,
+ const struct kernfs_ops *ops, void *priv,
+ const void *ns, struct lock_class_key *key)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline struct kernfs_node *
+kernfs_create_link(struct kernfs_node *parent, const char *name,
+ struct kernfs_node *target)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_remove(struct kernfs_node *kn) { }
+
+static inline int kernfs_remove_by_name_ns(struct kernfs_node *kn,
const char *name, const void *ns)
{ return -ENOSYS; }
-static inline int kernfs_rename_ns(struct sysfs_dirent *sd,
- struct sysfs_dirent *new_parent,
+static inline int kernfs_rename_ns(struct kernfs_node *kn,
+ struct kernfs_node *new_parent,
const char *new_name, const void *new_ns)
{ return -ENOSYS; }
-static inline int kernfs_setattr(struct sysfs_dirent *sd,
+static inline int kernfs_setattr(struct kernfs_node *kn,
const struct iattr *iattr)
{ return -ENOSYS; }
+static inline void kernfs_notify(struct kernfs_node *kn) { }
+
+static inline const void *kernfs_super_ns(struct super_block *sb)
+{ return NULL; }
+
+static inline struct dentry *
+kernfs_mount_ns(struct file_system_type *fs_type, int flags,
+ struct kernfs_root *root, const void *ns)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_kill_sb(struct super_block *sb) { }
+
+static inline void kernfs_init(void) { }
+
#endif /* CONFIG_SYSFS */
-static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
+static inline struct kernfs_node *
+kernfs_find_and_get(struct kernfs_node *kn, const char *name)
+{
+ return kernfs_find_and_get_ns(kn, name, NULL);
+}
+
+static inline struct kernfs_node *
+kernfs_create_dir(struct kernfs_node *parent, const char *name, void *priv)
+{
+ return kernfs_create_dir_ns(parent, name, priv, NULL);
+}
+
+static inline struct kernfs_node *
+kernfs_create_file_ns(struct kernfs_node *parent, const char *name,
+ umode_t mode, loff_t size, const struct kernfs_ops *ops,
+ void *priv, const void *ns)
+{
+ struct lock_class_key *key = NULL;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ key = (struct lock_class_key *)&ops->lockdep_key;
+#endif
+ return kernfs_create_file_ns_key(parent, name, mode, size, ops, priv,
+ ns, key);
+}
+
+static inline struct kernfs_node *
+kernfs_create_file(struct kernfs_node *parent, const char *name, umode_t mode,
+ loff_t size, const struct kernfs_ops *ops, void *priv)
+{
+ return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
+}
+
+static inline int kernfs_remove_by_name(struct kernfs_node *parent,
const char *name)
{
return kernfs_remove_by_name_ns(parent, name, NULL);
}
+static inline struct dentry *
+kernfs_mount(struct file_system_type *fs_type, int flags,
+ struct kernfs_root *root)
+{
+ return kernfs_mount_ns(fs_type, flags, root, NULL);
+}
+
#endif /* __LINUX_KERNFS_H */
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