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                   struct inode *inode, const char *name, void *buffer,
  34                   size_t size);
  35        int (*set)(const struct xattr_handler *, struct dentry *dentry,
  36                   struct inode *inode, const char *name, const void *buffer,
  37                   size_t size, int flags);
  38};
  39
  40const char *xattr_full_name(const struct xattr_handler *, const char *);
  41
  42struct xattr {
  43        const char *name;
  44        void *value;
  45        size_t value_len;
  46};
  47
  48ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
  49ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
  50ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
  51int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
  52int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
  53int vfs_removexattr(struct dentry *, const char *);
  54
  55ssize_t generic_getxattr(struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size);
  56ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
  57int generic_setxattr(struct dentry *dentry, struct inode *inode,
  58                     const char *name, const void *value, size_t size, int flags);
  59int generic_removexattr(struct dentry *dentry, const char *name);
  60ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
  61                           char **xattr_value, size_t size, gfp_t flags);
  62
  63static inline const char *xattr_prefix(const struct xattr_handler *handler)
  64{
  65        return handler->prefix ?: handler->name;
  66}
  67
  68struct simple_xattrs {
  69        struct list_head head;
  70        spinlock_t lock;
  71};
  72
  73struct simple_xattr {
  74        struct list_head list;
  75        char *name;
  76        size_t size;
  77        char value[0];
  78};
  79
  80/*
  81 * initialize the simple_xattrs structure
  82 */
  83static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
  84{
  85        INIT_LIST_HEAD(&xattrs->head);
  86        spin_lock_init(&xattrs->lock);
  87}
  88
  89/*
  90 * free all the xattrs
  91 */
  92static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
  93{
  94        struct simple_xattr *xattr, *node;
  95
  96        list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
  97                kfree(xattr->name);
  98                kfree(xattr);
  99        }
 100}
 101
 102struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
 103int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
 104                     void *buffer, size_t size);
 105int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
 106                     const void *value, size_t size, int flags);
 107ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
 108                          size_t size);
 109void simple_xattr_list_add(struct simple_xattrs *xattrs,
 110                           struct simple_xattr *new_xattr);
 111
 112#endif  /* _LINUX_XATTR_H */
 113