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         if (S_ISLNK(inode->i_mode))
  84                 return -EOPNOTSUPP;
  85
  86         switch(type) {
  87                 case ACL_TYPE_ACCESS:
  88                         ea_name = POSIX_ACL_XATTR_ACCESS;
  89                         break;
  90                 case ACL_TYPE_DEFAULT:
  91                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  92                         if (!S_ISDIR(inode->i_mode))
  93                                 return acl ? -EACCES : 0;
  94                         break;
  95                 default:
  96                         return -EINVAL;
  97         }
  98         if (acl) {
  99                 size = posix_acl_xattr_size(acl->a_count);
 100                 value = kmalloc(size, GFP_KERNEL);
 101                 if (!value)
 102                         return -ENOMEM;
 103                 rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 104                 if (rc < 0)
 105                         goto out;
 106         }
 107         rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
 108 out:
 109         kfree(value);
 110
 111         if (!rc)
 112                 set_cached_acl(inode, type, acl);
 113
 114         return rc;
 115 }
 116
 117 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 118 {
 119         struct posix_acl *acl = NULL;
 120         int rc = 0;
 121
 122         if (S_ISLNK(inode->i_mode))
 123                 return 0;
 124
 125         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 126         if (IS_ERR(acl))
 127                 return PTR_ERR(acl);
 128
 129         if (acl) {
 130                 if (S_ISDIR(inode->i_mode)) {
 131                         rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
 132                         if (rc)
 133                                 goto cleanup;
 134                 }
 135                 rc = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
 136                 if (rc < 0)
 137                         goto cleanup; /* posix_acl_release(NULL) is no-op */
 138                 if (rc > 0)
 139                         rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
 140 cleanup:
 141                 posix_acl_release(acl);
 142         } else
 143                 inode->i_mode &= ~current_umask();
 144
 145         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
 146                                inode->i_mode;
 147
 148         return rc;
 149 }
 150
 151 int jfs_acl_chmod(struct inode *inode)
 152 {
 153         struct posix_acl *acl;
 154         int rc;
 155         tid_t tid;
 156
 157         if (S_ISLNK(inode->i_mode))
 158                 return -EOPNOTSUPP;
 159
 160         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 161         if (IS_ERR(acl) || !acl)
 162                 return PTR_ERR(acl);
 163
 164         rc = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
 165         if (rc)
 166                 return rc;
 167
 168         tid = txBegin(inode->i_sb, 0);
 169         mutex_lock(&JFS_IP(inode)->commit_mutex);
 170         rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
 171         if (!rc)
 172                 rc = txCommit(tid, 1, &inode, 0);
 173         txEnd(tid);
 174         mutex_unlock(&JFS_IP(inode)->commit_mutex);
 175
 176         posix_acl_release(acl);
 177         return rc;
 178 }