fs/btrfs/acl.c

   1 /*
   2  * Copyright (C) 2007 Red Hat.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/string.h>
  21 #include <linux/xattr.h>
  22 #include <linux/posix_acl_xattr.h>
  23 #include <linux/sched.h>
  24 #include "ctree.h"
  25 #include "xattr.h"
  26 #ifndef is_owner_or_cap
  27 #define is_owner_or_cap(inode)  \
  28         ((current->fsuid == (inode)->i_uid) || capable(CAP_FOWNER))
  29 #endif
  30
  31 static int btrfs_xattr_set_acl(struct inode *inode, int type,
  32                                const void *value, size_t size)
  33 {
  34         int ret = 0;
  35         struct posix_acl *acl;
  36
  37         if (!is_owner_or_cap(inode))
  38                 return -EPERM;
  39         if (value) {
  40                 acl = posix_acl_from_xattr(value, size);
  41                 if (acl == NULL) {
  42                         value = NULL;
  43                         size = 0;
  44                 } else if (IS_ERR(acl)) {
  45                         ret = PTR_ERR(acl);
  46                 } else {
  47                         ret = posix_acl_valid(acl);
  48                         posix_acl_release(acl);
  49                 }
  50                 if (ret)
  51                         return ret;
  52         }
  53         return btrfs_xattr_set(inode, type, "", value, size, 0);
  54 }
  55
  56 static int btrfs_xattr_get_acl(struct inode *inode, int type,
  57                                void *value, size_t size)
  58 {
  59         return btrfs_xattr_get(inode, type, "", value, size);
  60 }
  61 static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
  62                                       void *value, size_t size)
  63 {
  64         if (*name != '\0')
  65                return -EINVAL;
  66         return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
  67                                    value, size);
  68 }
  69 static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
  70                                       const void *value, size_t size, int flags)
  71 {
  72         if (*name != '\0')
  73                return -EINVAL;
  74         return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
  75                                    value, size);
  76 }
  77 static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
  78                                        void *value, size_t size)
  79 {
  80         if (*name != '\0')
  81                return -EINVAL;
  82         return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
  83                                    value, size);
  84 }
  85 static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
  86                                        const void *value, size_t size, int flags)
  87 {
  88         if (*name != '\0')
  89                return -EINVAL;
  90         return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
  91                                    value, size);
  92 }
  93 struct xattr_handler btrfs_xattr_acl_default_handler = {
  94         .prefix = POSIX_ACL_XATTR_DEFAULT,
  95         .list   = btrfs_xattr_generic_list,
  96         .get    = btrfs_xattr_acl_default_get,
  97         .set    = btrfs_xattr_acl_default_set,
  98 };
  99
 100 struct xattr_handler btrfs_xattr_acl_access_handler = {
 101         .prefix = POSIX_ACL_XATTR_ACCESS,
 102         .list   = btrfs_xattr_generic_list,
 103         .get    = btrfs_xattr_acl_access_get,
 104         .set    = btrfs_xattr_acl_access_set,
 105 };