fs/jfs/acl.c

   1 /*
   2  *   Copyright (C) International Business Machines  Corp., 2002-2004
   3  *   Copyright (C) Andreas Gruenbacher, 2001
   4  *   Copyright (C) Linus Torvalds, 1991, 1992
   5  *
   6  *   This program is free software;  you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  14  *   the GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program;  if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/fs.h>
  24 #include <linux/posix_acl_xattr.h>
  25 #include "jfs_incore.h"
  26 #include "jfs_txnmgr.h"
  27 #include "jfs_xattr.h"
  28 #include "jfs_acl.h"
  29
  30 struct posix_acl *jfs_get_acl(struct inode *inode, int type)
  31 {
  32         struct posix_acl *acl;
  33         char *ea_name;
  34         int size;
  35         char *value = NULL;
  36
  37         acl = get_cached_acl(inode, type);
  38         if (acl != ACL_NOT_CACHED)
  39                 return acl;
  40
  41         switch(type) {
  42                 case ACL_TYPE_ACCESS:
  43                         ea_name = POSIX_ACL_XATTR_ACCESS;
  44                         break;
  45                 case ACL_TYPE_DEFAULT:
  46                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  47                         break;
  48                 default:
  49                         return ERR_PTR(-EINVAL);
  50         }
  51
  52         size = __jfs_getxattr(inode, ea_name, NULL, 0);
  53
  54         if (size > 0) {
  55                 value = kmalloc(size, GFP_KERNEL);
  56                 if (!value)
  57                         return ERR_PTR(-ENOMEM);
  58                 size = __jfs_getxattr(inode, ea_name, value, size);
  59         }
  60
  61         if (size < 0) {
  62                 if (size == -ENODATA)
  63                         acl = NULL;
  64                 else
  65                         acl = ERR_PTR(size);
  66         } else {
  67                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
  68         }
  69         kfree(value);
  70         if (!IS_ERR(acl))
  71                 set_cached_acl(inode, type, acl);
  72         return acl;
  73 }
  74
  75 static int __jfs_set_acl(tid_t tid, struct inode *inode, int type,
  76                        struct posix_acl *acl)
  77 {
  78         char *ea_name;
  79         int rc;
  80         int size = 0;
  81         char *value = NULL;
  82
  83         switch (type) {
  84         case ACL_TYPE_ACCESS:
  85                 ea_name = POSIX_ACL_XATTR_ACCESS;
  86                 rc = posix_acl_equiv_mode(acl, &inode->i_mode);
  87                 if (rc < 0)
  88                         return rc;
  89                 if (rc == 0)
  90                         acl = NULL;
  91                 break;
  92         case ACL_TYPE_DEFAULT:
  93                 ea_name = POSIX_ACL_XATTR_DEFAULT;
  94                 break;
  95         default:
  96                 return -EINVAL;
  97         }
  98
  99         if (acl) {
 100                 size = posix_acl_xattr_size(acl->a_count);
 101                 value = kmalloc(size, GFP_KERNEL);
 102                 if (!value)
 103                         return -ENOMEM;
 104                 rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 105                 if (rc < 0)
 106                         goto out;
 107         }
 108         rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
 109 out:
 110         kfree(value);
 111
 112         if (!rc)
 113                 set_cached_acl(inode, type, acl);
 114
 115         return rc;
 116 }
 117
 118 int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 119 {
 120         int rc;
 121         tid_t tid;
 122
 123         tid = txBegin(inode->i_sb, 0);
 124         mutex_lock(&JFS_IP(inode)->commit_mutex);
 125         rc = __jfs_set_acl(tid, inode, type, acl);
 126         if (!rc)
 127                 rc = txCommit(tid, 1, &inode, 0);
 128         txEnd(tid);
 129         mutex_unlock(&JFS_IP(inode)->commit_mutex);
 130         return rc;
 131 }
 132
 133 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 134 {
 135         struct posix_acl *default_acl, *acl;
 136         int rc = 0;
 137
 138         rc = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
 139         if (rc)
 140                 return rc;
 141
 142         if (default_acl) {
 143                 rc = __jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, default_acl);
 144                 posix_acl_release(default_acl);
 145         }
 146
 147         if (acl) {
 148                 if (!rc)
 149                         rc = __jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
 150                 posix_acl_release(acl);
 151         }
 152
 153         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
 154                                inode->i_mode;
 155
 156         return rc;
 157 }