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
  19 struct inode;
  20 struct dentry;
  21
  22 struct xattr_handler {
  23         const char *prefix;
  24         int flags;      /* fs private flags passed back to the handlers */
  25         size_t (*list)(struct dentry *dentry, char *list, size_t list_size,
  26                        const char *name, size_t name_len, int handler_flags);
  27         int (*get)(struct dentry *dentry, const char *name, void *buffer,
  28                    size_t size, int handler_flags);
  29         int (*set)(struct dentry *dentry, const char *name, const void *buffer,
  30                    size_t size, int flags, int handler_flags);
  31 };
  32
  33 struct xattr {
  34         char *name;
  35         void *value;
  36         size_t value_len;
  37 };
  38
  39 ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
  40 ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
  41 ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
  42 int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
  43 int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
  44 int vfs_removexattr(struct dentry *, const char *);
  45
  46 ssize_t generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size);
  47 ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
  48 int generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
  49 int generic_removexattr(struct dentry *dentry, const char *name);
  50 ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
  51                            char **xattr_value, size_t size, gfp_t flags);
  52 int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
  53                   const char *value, size_t size, gfp_t flags);
  54
  55 struct simple_xattrs {
  56         struct list_head head;
  57         spinlock_t lock;
  58 };
  59
  60 struct simple_xattr {
  61         struct list_head list;
  62         char *name;
  63         size_t size;
  64         char value[0];
  65 };
  66
  67 /*
  68  * initialize the simple_xattrs structure
  69  */
  70 static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
  71 {
  72         INIT_LIST_HEAD(&xattrs->head);
  73         spin_lock_init(&xattrs->lock);
  74 }
  75
  76 /*
  77  * free all the xattrs
  78  */
  79 static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
  80 {
  81         struct simple_xattr *xattr, *node;
  82
  83         list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
  84                 kfree(xattr->name);
  85                 kfree(xattr);
  86         }
  87 }
  88
  89 struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
  90 int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
  91                      void *buffer, size_t size);
  92 int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
  93                      const void *value, size_t size, int flags);
  94 int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name);
  95 ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
  96                           size_t size);
  97 void simple_xattr_list_add(struct simple_xattrs *xattrs,
  98                            struct simple_xattr *new_xattr);
  99
 100 #endif  /* _LINUX_XATTR_H */