xattr.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
File: linux/xattr.h
Extended attributes handling.
Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
*/
#ifndef _LINUX_XATTR_H
#define _LINUX_XATTR_H
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/user_namespace.h>
#include <uapi/linux/xattr.h>
struct inode;
struct dentry;
/*
* struct xattr_handler: When @name is set, match attributes with exactly that
* name. When @prefix is set instead, match attributes with that prefix and
* with a non-empty suffix.
*/
struct xattr_handler {
const char *name;
const char *prefix;
int flags; /* fs private flags */
bool (*list)(struct dentry *dentry);
int (*get)(const struct xattr_handler *, struct dentry *dentry,
struct inode *inode, const char *name, void *buffer,
size_t size);
int (*set)(const struct xattr_handler *,
struct user_namespace *mnt_userns, struct dentry *dentry,
struct inode *inode, const char *name, const void *buffer,
size_t size, int flags);
};
const char *xattr_full_name(const struct xattr_handler *, const char *);
struct xattr {
const char *name;
void *value;
size_t value_len;
};
ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct user_namespace *, struct dentry *, const char *,
void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr(struct user_namespace *, struct dentry *, struct inode *,
const char *, const void *, size_t, int);
int __vfs_setxattr_noperm(struct user_namespace *, struct dentry *,
const char *, const void *, size_t, int);
int __vfs_setxattr_locked(struct user_namespace *, struct dentry *,
const char *, const void *, size_t, int,
struct inode **);
int vfs_setxattr(struct user_namespace *, struct dentry *, const char *,
const void *, size_t, int);
int __vfs_removexattr(struct user_namespace *, struct dentry *, const char *);
int __vfs_removexattr_locked(struct user_namespace *, struct dentry *,
const char *, struct inode **);
int vfs_removexattr(struct user_namespace *, struct dentry *, const char *);
ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
ssize_t vfs_getxattr_alloc(struct user_namespace *mnt_userns,
struct dentry *dentry, const char *name,
char **xattr_value, size_t size, gfp_t flags);
int xattr_supported_namespace(struct inode *inode, const char *prefix);
static inline const char *xattr_prefix(const struct xattr_handler *handler)
{
return handler->prefix ?: handler->name;
}
struct simple_xattrs {
struct list_head head;
spinlock_t lock;
};
struct simple_xattr {
struct list_head list;
char *name;
size_t size;
char value[];
};
/*
* initialize the simple_xattrs structure
*/
static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
{
INIT_LIST_HEAD(&xattrs->head);
spin_lock_init(&xattrs->lock);
}
/*
* free all the xattrs
*/
static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
{
struct simple_xattr *xattr, *node;
list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
kfree(xattr->name);
kvfree(xattr);
}
}
struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
void *buffer, size_t size);
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
const void *value, size_t size, int flags,
ssize_t *removed_size);
ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
size_t size);
void simple_xattr_list_add(struct simple_xattrs *xattrs,
struct simple_xattr *new_xattr);
#endif /* _LINUX_XATTR_H */