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_txnmgr.h"
  27 #include "jfs_xattr.h"
  28 #include "jfs_acl.h"
  29
  30 static struct posix_acl *jfs_get_acl(struct inode *inode, int type)
  31 {
  32         struct posix_acl *acl;
  33         char *ea_name;
  34         struct jfs_inode_info *ji = JFS_IP(inode);
  35         struct posix_acl **p_acl;
  36         int size;
  37         char *value = NULL;
  38
  39         switch(type) {
  40                 case ACL_TYPE_ACCESS:
  41                         ea_name = POSIX_ACL_XATTR_ACCESS;
  42                         p_acl = &ji->i_acl;
  43                         break;
  44                 case ACL_TYPE_DEFAULT:
  45                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  46                         p_acl = &ji->i_default_acl;
  47                         break;
  48                 default:
  49                         return ERR_PTR(-EINVAL);
  50         }
  51
  52         if (*p_acl != JFS_ACL_NOT_CACHED)
  53                 return posix_acl_dup(*p_acl);
  54
  55         size = __jfs_getxattr(inode, ea_name, NULL, 0);
  56
  57         if (size > 0) {
  58                 value = kmalloc(size, GFP_KERNEL);
  59                 if (!value)
  60                         return ERR_PTR(-ENOMEM);
  61                 size = __jfs_getxattr(inode, ea_name, value, size);
  62         }
  63
  64         if (size < 0) {
  65                 if (size == -ENODATA) {
  66                         *p_acl = NULL;
  67                         acl = NULL;
  68                 } else
  69                         acl = ERR_PTR(size);
  70         } else {
  71                 acl = posix_acl_from_xattr(value, size);
  72                 if (!IS_ERR(acl))
  73                         *p_acl = posix_acl_dup(acl);
  74         }
  75         kfree(value);
  76         return acl;
  77 }
  78
  79 static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
  80                        struct posix_acl *acl)
  81 {
  82         char *ea_name;
  83         struct jfs_inode_info *ji = JFS_IP(inode);
  84         struct posix_acl **p_acl;
  85         int rc;
  86         int size = 0;
  87         char *value = NULL;
  88
  89         if (S_ISLNK(inode->i_mode))
  90                 return -EOPNOTSUPP;
  91
  92         switch(type) {
  93                 case ACL_TYPE_ACCESS:
  94                         ea_name = POSIX_ACL_XATTR_ACCESS;
  95                         p_acl = &ji->i_acl;
  96                         break;
  97                 case ACL_TYPE_DEFAULT:
  98                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  99                         p_acl = &ji->i_default_acl;
 100                         if (!S_ISDIR(inode->i_mode))
 101                                 return acl ? -EACCES : 0;
 102                         break;
 103                 default:
 104                         return -EINVAL;
 105         }
 106         if (acl) {
 107                 size = posix_acl_xattr_size(acl->a_count);
 108                 value = kmalloc(size, GFP_KERNEL);
 109                 if (!value)
 110                         return -ENOMEM;
 111                 rc = posix_acl_to_xattr(acl, value, size);
 112                 if (rc < 0)
 113                         goto out;
 114         }
 115         rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
 116 out:
 117         kfree(value);
 118
 119         if (!rc) {
 120                 if (*p_acl && (*p_acl != JFS_ACL_NOT_CACHED))
 121                         posix_acl_release(*p_acl);
 122                 *p_acl = posix_acl_dup(acl);
 123         }
 124         return rc;
 125 }
 126
 127 static int jfs_check_acl(struct inode *inode, int mask)
 128 {
 129         struct jfs_inode_info *ji = JFS_IP(inode);
 130
 131         if (ji->i_acl == JFS_ACL_NOT_CACHED) {
 132                 struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 133                 if (IS_ERR(acl))
 134                         return PTR_ERR(acl);
 135                 posix_acl_release(acl);
 136         }
 137
 138         if (ji->i_acl)
 139                 return posix_acl_permission(inode, ji->i_acl, mask);
 140         return -EAGAIN;
 141 }
 142
 143 int jfs_permission(struct inode *inode, int mask, struct nameidata *nd)
 144 {
 145         return generic_permission(inode, mask, jfs_check_acl);
 146 }
 147
 148 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 149 {
 150         struct posix_acl *acl = NULL;
 151         struct posix_acl *clone;
 152         mode_t mode;
 153         int rc = 0;
 154
 155         if (S_ISLNK(inode->i_mode))
 156                 return 0;
 157
 158         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 159         if (IS_ERR(acl))
 160                 return PTR_ERR(acl);
 161
 162         if (acl) {
 163                 if (S_ISDIR(inode->i_mode)) {
 164                         rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
 165                         if (rc)
 166                                 goto cleanup;
 167                 }
 168                 clone = posix_acl_clone(acl, GFP_KERNEL);
 169                 if (!clone) {
 170                         rc = -ENOMEM;
 171                         goto cleanup;
 172                 }
 173                 mode = inode->i_mode;
 174                 rc = posix_acl_create_masq(clone, &mode);
 175                 if (rc >= 0) {
 176                         inode->i_mode = mode;
 177                         if (rc > 0)
 178                                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
 179                                                  clone);
 180                 }
 181                 posix_acl_release(clone);
 182 cleanup:
 183                 posix_acl_release(acl);
 184         } else
 185                 inode->i_mode &= ~current->fs->umask;
 186
 187         return rc;
 188 }
 189
 190 static int jfs_acl_chmod(struct inode *inode)
 191 {
 192         struct posix_acl *acl, *clone;
 193         int rc;
 194
 195         if (S_ISLNK(inode->i_mode))
 196                 return -EOPNOTSUPP;
 197
 198         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 199         if (IS_ERR(acl) || !acl)
 200                 return PTR_ERR(acl);
 201
 202         clone = posix_acl_clone(acl, GFP_KERNEL);
 203         posix_acl_release(acl);
 204         if (!clone)
 205                 return -ENOMEM;
 206
 207         rc = posix_acl_chmod_masq(clone, inode->i_mode);
 208         if (!rc) {
 209                 tid_t tid = txBegin(inode->i_sb, 0);
 210                 down(&JFS_IP(inode)->commit_sem);
 211                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
 212                 if (!rc)
 213                         rc = txCommit(tid, 1, &inode, 0);
 214                 txEnd(tid);
 215                 up(&JFS_IP(inode)->commit_sem);
 216         }
 217
 218         posix_acl_release(clone);
 219         return rc;
 220 }
 221
 222 int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
 223 {
 224         struct inode *inode = dentry->d_inode;
 225         int rc;
 226
 227         rc = inode_change_ok(inode, iattr);
 228         if (rc)
 229                 return rc;
 230
 231         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 232             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 233                 if (DQUOT_TRANSFER(inode, iattr))
 234                         return -EDQUOT;
 235         }
 236
 237         rc = inode_setattr(inode, iattr);
 238
 239         if (!rc && (iattr->ia_valid & ATTR_MODE))
 240                 rc = jfs_acl_chmod(inode);
 241
 242         return rc;
 243 }