fs/xfs/xfs_acl.h

   1 /*
   2  * Copyright (c) 2001-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_ACL_H__
  19 #define __XFS_ACL_H__
  20
  21 struct inode;
  22 struct posix_acl;
  23 struct xfs_inode;
  24
  25 #define XFS_ACL_NOT_PRESENT (-1)
  26
  27 /* On-disk XFS access control list structure */
  28 struct xfs_acl_entry {
  29         __be32  ae_tag;
  30         __be32  ae_id;
  31         __be16  ae_perm;
  32         __be16  ae_pad;         /* fill the implicit hole in the structure */
  33 };
  34
  35 struct xfs_acl {
  36         __be32                  acl_cnt;
  37         struct xfs_acl_entry    acl_entry[0];
  38 };
  39
  40 /*
  41  * The number of ACL entries allowed is defined by the on-disk format.
  42  * For v4 superblocks, that is limited to 25 entries. For v5 superblocks, it is
  43  * limited only by the maximum size of the xattr that stores the information.
  44  */
  45 #define XFS_ACL_MAX_ENTRIES(mp) \
  46         (xfs_sb_version_hascrc(&mp->m_sb) \
  47                 ?  (XATTR_SIZE_MAX - sizeof(struct xfs_acl)) / \
  48                                                 sizeof(struct xfs_acl_entry) \
  49                 : 25)
  50
  51 #define XFS_ACL_MAX_SIZE(mp) \
  52         (sizeof(struct xfs_acl) + \
  53                 sizeof(struct xfs_acl_entry) * XFS_ACL_MAX_ENTRIES((mp)))
  54
  55 /* On-disk XFS extended attribute names */
  56 #define SGI_ACL_FILE            (unsigned char *)"SGI_ACL_FILE"
  57 #define SGI_ACL_DEFAULT         (unsigned char *)"SGI_ACL_DEFAULT"
  58 #define SGI_ACL_FILE_SIZE       (sizeof(SGI_ACL_FILE)-1)
  59 #define SGI_ACL_DEFAULT_SIZE    (sizeof(SGI_ACL_DEFAULT)-1)
  60
  61 #ifdef CONFIG_XFS_POSIX_ACL
  62 extern struct posix_acl *xfs_get_acl(struct inode *inode, int type);
  63 extern int xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
  64 extern int posix_acl_access_exists(struct inode *inode);
  65 extern int posix_acl_default_exists(struct inode *inode);
  66 #else
  67 static inline struct posix_acl *xfs_get_acl(struct inode *inode, int type)
  68 {
  69         return NULL;
  70 }
  71 # define xfs_set_acl                                    NULL
  72 # define posix_acl_access_exists(inode)                 0
  73 # define posix_acl_default_exists(inode)                0
  74 #endif /* CONFIG_XFS_POSIX_ACL */
  75 #endif  /* __XFS_ACL_H__ */