LXR linux/include/linux/xattr.h

   1/*
   2  File: linux/xattr.h
   3
   4  Extended attributes handling.
   5
   6  Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
   7  Copyright (c) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
   8  Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
   9*/
  10#ifndef _LINUX_XATTR_H
  11#define _LINUX_XATTR_H
  12
  13
  14#include <linux/slab.h>
  15#include <linux/types.h>
  16#include <linux/spinlock.h>
  17#include <uapi/linux/xattr.h>
  18
  19struct inode;
  20struct dentry;
  21
  22/*
  23 * struct xattr_handler: When @name is set, match attributes with exactly that
  24 * name.  When @prefix is set instead, match attributes with that prefix and
  25 * with a non-empty suffix.
  26 */
  27struct xattr_handler {
  28        const char *name;
  29        const char *prefix;
  30        int flags;      /* fs private flags */
  31        bool (*list)(struct dentry *dentry);
  32        int (*get)(const struct xattr_handler *, struct dentry *dentry,
  33                   const char *name, void *buffer, size_t size);
  34        int (*set)(const struct xattr_handler *, struct dentry *dentry,
  35                   const char *name, const void *buffer, size_t size,
  36                   int flags);
  37};
  38
  39const char *xattr_full_name(const struct xattr_handler *, const char *);
  40
  41struct xattr {
  42        const char *name;
  43        void *value;
  44        size_t value_len;
  45};
  46
  47ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
  48ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
  49ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
  50int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
  51int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
  52int vfs_removexattr(struct dentry *, const char *);
  53
  54ssize_t generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size);
  55ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
  56int generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
  57int generic_removexattr(struct dentry *dentry, const char *name);
  58ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
  59                           char **xattr_value, size_t size, gfp_t flags);
  60
  61static inline const char *xattr_prefix(const struct xattr_handler *handler)
  62{
  63        return handler->prefix ?: handler->name;
  64}
  65
  66struct simple_xattrs {
  67        struct list_head head;
  68        spinlock_t lock;
  69};
  70
  71struct simple_xattr {
  72        struct list_head list;
  73        char *name;
  74        size_t size;
  75        char value[0];
  76};
  77
  78/*
  79 * initialize the simple_xattrs structure
  80 */
  81static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
  82{
  83        INIT_LIST_HEAD(&xattrs->head);
  84        spin_lock_init(&xattrs->lock);
  85}
  86
  87/*
  88 * free all the xattrs
  89 */
  90static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
  91{
  92        struct simple_xattr *xattr, *node;
  93
  94        list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
  95                kfree(xattr->name);
  96                kfree(xattr);
  97        }
  98}
  99
 100struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
 101int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
 102                     void *buffer, size_t size);
 103int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
 104                     const void *value, size_t size, int flags);
 105ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
 106                          size_t size);
 107void simple_xattr_list_add(struct simple_xattrs *xattrs,
 108                           struct simple_xattr *new_xattr);
 109
 110#endif  /* _LINUX_XATTR_H */
 111