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/fs.h>
  23 #include <linux/posix_acl_xattr.h>
  24 #include "jfs_incore.h"
  25 #include "jfs_txnmgr.h"
  26 #include "jfs_xattr.h"
  27 #include "jfs_acl.h"
  28
  29 static struct posix_acl *jfs_get_acl(struct inode *inode, int type)
  30 {
  31         struct posix_acl *acl;
  32         char *ea_name;
  33         int size;
  34         char *value = NULL;
  35
  36         acl = get_cached_acl(inode, type);
  37         if (acl != ACL_NOT_CACHED)
  38                 return acl;
  39
  40         switch(type) {
  41                 case ACL_TYPE_ACCESS:
  42                         ea_name = POSIX_ACL_XATTR_ACCESS;
  43                         break;
  44                 case ACL_TYPE_DEFAULT:
  45                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  46                         break;
  47                 default:
  48                         return ERR_PTR(-EINVAL);
  49         }
  50
  51         size = __jfs_getxattr(inode, ea_name, NULL, 0);
  52
  53         if (size > 0) {
  54                 value = kmalloc(size, GFP_KERNEL);
  55                 if (!value)
  56                         return ERR_PTR(-ENOMEM);
  57                 size = __jfs_getxattr(inode, ea_name, value, size);
  58         }
  59
  60         if (size < 0) {
  61                 if (size == -ENODATA)
  62                         acl = NULL;
  63                 else
  64                         acl = ERR_PTR(size);
  65         } else {
  66                 acl = posix_acl_from_xattr(value, size);
  67         }
  68         kfree(value);
  69         if (!IS_ERR(acl))
  70                 set_cached_acl(inode, type, acl);
  71         return acl;
  72 }
  73
  74 static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
  75                        struct posix_acl *acl)
  76 {
  77         char *ea_name;
  78         int rc;
  79         int size = 0;
  80         char *value = NULL;
  81
  82         if (S_ISLNK(inode->i_mode))
  83                 return -EOPNOTSUPP;
  84
  85         switch(type) {
  86                 case ACL_TYPE_ACCESS:
  87                         ea_name = POSIX_ACL_XATTR_ACCESS;
  88                         break;
  89                 case ACL_TYPE_DEFAULT:
  90                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  91                         if (!S_ISDIR(inode->i_mode))
  92                                 return acl ? -EACCES : 0;
  93                         break;
  94                 default:
  95                         return -EINVAL;
  96         }
  97         if (acl) {
  98                 size = posix_acl_xattr_size(acl->a_count);
  99                 value = kmalloc(size, GFP_KERNEL);
 100                 if (!value)
 101                         return -ENOMEM;
 102                 rc = posix_acl_to_xattr(acl, value, size);
 103                 if (rc < 0)
 104                         goto out;
 105         }
 106         rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
 107 out:
 108         kfree(value);
 109
 110         if (!rc)
 111                 set_cached_acl(inode, type, acl);
 112
 113         return rc;
 114 }
 115
 116 int jfs_check_acl(struct inode *inode, int mask)
 117 {
 118         struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 119
 120         if (IS_ERR(acl))
 121                 return PTR_ERR(acl);
 122         if (acl) {
 123                 int error = posix_acl_permission(inode, acl, mask);
 124                 posix_acl_release(acl);
 125                 return error;
 126         }
 127
 128         return -EAGAIN;
 129 }
 130
 131 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 132 {
 133         struct posix_acl *acl = NULL;
 134         struct posix_acl *clone;
 135         mode_t mode;
 136         int rc = 0;
 137
 138         if (S_ISLNK(inode->i_mode))
 139                 return 0;
 140
 141         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 142         if (IS_ERR(acl))
 143                 return PTR_ERR(acl);
 144
 145         if (acl) {
 146                 if (S_ISDIR(inode->i_mode)) {
 147                         rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
 148                         if (rc)
 149                                 goto cleanup;
 150                 }
 151                 clone = posix_acl_clone(acl, GFP_KERNEL);
 152                 if (!clone) {
 153                         rc = -ENOMEM;
 154                         goto cleanup;
 155                 }
 156                 mode = inode->i_mode;
 157                 rc = posix_acl_create_masq(clone, &mode);
 158                 if (rc >= 0) {
 159                         inode->i_mode = mode;
 160                         if (rc > 0)
 161                                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
 162                                                  clone);
 163                 }
 164                 posix_acl_release(clone);
 165 cleanup:
 166                 posix_acl_release(acl);
 167         } else
 168                 inode->i_mode &= ~current_umask();
 169
 170         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
 171                                inode->i_mode;
 172
 173         return rc;
 174 }
 175
 176 int jfs_acl_chmod(struct inode *inode)
 177 {
 178         struct posix_acl *acl, *clone;
 179         int rc;
 180
 181         if (S_ISLNK(inode->i_mode))
 182                 return -EOPNOTSUPP;
 183
 184         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 185         if (IS_ERR(acl) || !acl)
 186                 return PTR_ERR(acl);
 187
 188         clone = posix_acl_clone(acl, GFP_KERNEL);
 189         posix_acl_release(acl);
 190         if (!clone)
 191                 return -ENOMEM;
 192
 193         rc = posix_acl_chmod_masq(clone, inode->i_mode);
 194         if (!rc) {
 195                 tid_t tid = txBegin(inode->i_sb, 0);
 196                 mutex_lock(&JFS_IP(inode)->commit_mutex);
 197                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
 198                 if (!rc)
 199                         rc = txCommit(tid, 1, &inode, 0);
 200                 txEnd(tid);
 201                 mutex_unlock(&JFS_IP(inode)->commit_mutex);
 202         }
 203
 204         posix_acl_release(clone);
 205         return rc;
 206 }