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/quotaops.h>
  24 #include <linux/posix_acl_xattr.h>
  25 #include "jfs_incore.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         struct jfs_inode_info *ji = JFS_IP(inode);
  34         struct posix_acl **p_acl;
  35         int size;
  36         char *value = NULL;
  37
  38         switch(type) {
  39                 case ACL_TYPE_ACCESS:
  40                         ea_name = POSIX_ACL_XATTR_ACCESS;
  41                         p_acl = &ji->i_acl;
  42                         break;
  43                 case ACL_TYPE_DEFAULT:
  44                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  45                         p_acl = &ji->i_default_acl;
  46                         break;
  47                 default:
  48                         return ERR_PTR(-EINVAL);
  49         }
  50
  51         if (*p_acl != JFS_ACL_NOT_CACHED)
  52                 return posix_acl_dup(*p_acl);
  53
  54         size = __jfs_getxattr(inode, ea_name, NULL, 0);
  55
  56         if (size > 0) {
  57                 value = kmalloc(size, GFP_KERNEL);
  58                 if (!value)
  59                         return ERR_PTR(-ENOMEM);
  60                 size = __jfs_getxattr(inode, ea_name, value, size);
  61         }
  62
  63         if (size < 0) {
  64                 if (size == -ENODATA) {
  65                         *p_acl = NULL;
  66                         acl = NULL;
  67                 } else
  68                         acl = ERR_PTR(size);
  69         } else {
  70                 acl = posix_acl_from_xattr(value, size);
  71                 if (!IS_ERR(acl))
  72                         *p_acl = posix_acl_dup(acl);
  73         }
  74         kfree(value);
  75         return acl;
  76 }
  77
  78 static int jfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
  79 {
  80         char *ea_name;
  81         struct jfs_inode_info *ji = JFS_IP(inode);
  82         struct posix_acl **p_acl;
  83         int rc;
  84         int size = 0;
  85         char *value = NULL;
  86
  87         if (S_ISLNK(inode->i_mode))
  88                 return -EOPNOTSUPP;
  89
  90         switch(type) {
  91                 case ACL_TYPE_ACCESS:
  92                         ea_name = POSIX_ACL_XATTR_ACCESS;
  93                         p_acl = &ji->i_acl;
  94                         break;
  95                 case ACL_TYPE_DEFAULT:
  96                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  97                         p_acl = &ji->i_default_acl;
  98                         if (!S_ISDIR(inode->i_mode))
  99                                 return acl ? -EACCES : 0;
 100                         break;
 101                 default:
 102                         return -EINVAL;
 103         }
 104         if (acl) {
 105                 size = posix_acl_xattr_size(acl->a_count);
 106                 value = kmalloc(size, GFP_KERNEL);
 107                 if (!value)
 108                         return -ENOMEM;
 109                 rc = posix_acl_to_xattr(acl, value, size);
 110                 if (rc < 0)
 111                         goto out;
 112         }
 113         rc = __jfs_setxattr(inode, ea_name, value, size, 0);
 114 out:
 115         kfree(value);
 116
 117         if (!rc) {
 118                 if (*p_acl && (*p_acl != JFS_ACL_NOT_CACHED))
 119                         posix_acl_release(*p_acl);
 120                 *p_acl = posix_acl_dup(acl);
 121         }
 122         return rc;
 123 }
 124
 125 static int jfs_check_acl(struct inode *inode, int mask)
 126 {
 127         struct jfs_inode_info *ji = JFS_IP(inode);
 128
 129         if (ji->i_acl == JFS_ACL_NOT_CACHED) {
 130                 struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 131                 if (IS_ERR(acl))
 132                         return PTR_ERR(acl);
 133                 posix_acl_release(acl);
 134         }
 135
 136         if (ji->i_acl)
 137                 return posix_acl_permission(inode, ji->i_acl, mask);
 138         return -EAGAIN;
 139 }
 140
 141 int jfs_permission(struct inode *inode, int mask, struct nameidata *nd)
 142 {
 143         return generic_permission(inode, mask, jfs_check_acl);
 144 }
 145
 146 int jfs_init_acl(struct inode *inode, struct inode *dir)
 147 {
 148         struct posix_acl *acl = NULL;
 149         struct posix_acl *clone;
 150         mode_t mode;
 151         int rc = 0;
 152
 153         if (S_ISLNK(inode->i_mode))
 154                 return 0;
 155
 156         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 157         if (IS_ERR(acl))
 158                 return PTR_ERR(acl);
 159
 160         if (acl) {
 161                 if (S_ISDIR(inode->i_mode)) {
 162                         rc = jfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
 163                         if (rc)
 164                                 goto cleanup;
 165                 }
 166                 clone = posix_acl_clone(acl, GFP_KERNEL);
 167                 if (!clone) {
 168                         rc = -ENOMEM;
 169                         goto cleanup;
 170                 }
 171                 mode = inode->i_mode;
 172                 rc = posix_acl_create_masq(clone, &mode);
 173                 if (rc >= 0) {
 174                         inode->i_mode = mode;
 175                         if (rc > 0)
 176                                 rc = jfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
 177                 }
 178                 posix_acl_release(clone);
 179 cleanup:
 180                 posix_acl_release(acl);
 181         } else
 182                 inode->i_mode &= ~current->fs->umask;
 183
 184         return rc;
 185 }
 186
 187 static int jfs_acl_chmod(struct inode *inode)
 188 {
 189         struct posix_acl *acl, *clone;
 190         int rc;
 191
 192         if (S_ISLNK(inode->i_mode))
 193                 return -EOPNOTSUPP;
 194
 195         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 196         if (IS_ERR(acl) || !acl)
 197                 return PTR_ERR(acl);
 198
 199         clone = posix_acl_clone(acl, GFP_KERNEL);
 200         posix_acl_release(acl);
 201         if (!clone)
 202                 return -ENOMEM;
 203
 204         rc = posix_acl_chmod_masq(clone, inode->i_mode);
 205         if (!rc)
 206                 rc = jfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
 207
 208         posix_acl_release(clone);
 209         return rc;
 210 }
 211
 212 int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
 213 {
 214         struct inode *inode = dentry->d_inode;
 215         int rc;
 216
 217         rc = inode_change_ok(inode, iattr);
 218         if (rc)
 219                 return rc;
 220
 221         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 222             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 223                 if (DQUOT_TRANSFER(inode, iattr))
 224                         return -EDQUOT;
 225         }
 226
 227         rc = inode_setattr(inode, iattr);
 228
 229         if (!rc && (iattr->ia_valid & ATTR_MODE))
 230                 rc = jfs_acl_chmod(inode);
 231
 232         return rc;
 233 }