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         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(value, size);
  68         }
  69         kfree(value);
  70         if (!IS_ERR(acl)) {
  71                 set_cached_acl(inode, type, acl);
  72                 posix_acl_release(acl);
  73         }
  74         return acl;
  75 }
  76
  77 static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
  78                        struct posix_acl *acl)
  79 {
  80         char *ea_name;
  81         int rc;
  82         int size = 0;
  83         char *value = NULL;
  84
  85         if (S_ISLNK(inode->i_mode))
  86                 return -EOPNOTSUPP;
  87
  88         switch(type) {
  89                 case ACL_TYPE_ACCESS:
  90                         ea_name = POSIX_ACL_XATTR_ACCESS;
  91                         break;
  92                 case ACL_TYPE_DEFAULT:
  93                         ea_name = POSIX_ACL_XATTR_DEFAULT;
  94                         if (!S_ISDIR(inode->i_mode))
  95                                 return acl ? -EACCES : 0;
  96                         break;
  97                 default:
  98                         return -EINVAL;
  99         }
 100         if (acl) {
 101                 size = posix_acl_xattr_size(acl->a_count);
 102                 value = kmalloc(size, GFP_KERNEL);
 103                 if (!value)
 104                         return -ENOMEM;
 105                 rc = posix_acl_to_xattr(acl, value, size);
 106                 if (rc < 0)
 107                         goto out;
 108         }
 109         rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
 110 out:
 111         kfree(value);
 112
 113         if (!rc)
 114                 set_cached_acl(inode, type, acl);
 115
 116         return rc;
 117 }
 118
 119 static int jfs_check_acl(struct inode *inode, int mask)
 120 {
 121         if (inode->i_acl == ACL_NOT_CACHED) {
 122                 struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 123                 if (IS_ERR(acl))
 124                         return PTR_ERR(acl);
 125                 posix_acl_release(acl);
 126         }
 127
 128         if (inode->i_acl)
 129                 return posix_acl_permission(inode, inode->i_acl, mask);
 130         return -EAGAIN;
 131 }
 132
 133 int jfs_permission(struct inode *inode, int mask)
 134 {
 135         return generic_permission(inode, mask, jfs_check_acl);
 136 }
 137
 138 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 139 {
 140         struct posix_acl *acl = NULL;
 141         struct posix_acl *clone;
 142         mode_t mode;
 143         int rc = 0;
 144
 145         if (S_ISLNK(inode->i_mode))
 146                 return 0;
 147
 148         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 149         if (IS_ERR(acl))
 150                 return PTR_ERR(acl);
 151
 152         if (acl) {
 153                 if (S_ISDIR(inode->i_mode)) {
 154                         rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
 155                         if (rc)
 156                                 goto cleanup;
 157                 }
 158                 clone = posix_acl_clone(acl, GFP_KERNEL);
 159                 if (!clone) {
 160                         rc = -ENOMEM;
 161                         goto cleanup;
 162                 }
 163                 mode = inode->i_mode;
 164                 rc = posix_acl_create_masq(clone, &mode);
 165                 if (rc >= 0) {
 166                         inode->i_mode = mode;
 167                         if (rc > 0)
 168                                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
 169                                                  clone);
 170                 }
 171                 posix_acl_release(clone);
 172 cleanup:
 173                 posix_acl_release(acl);
 174         } else
 175                 inode->i_mode &= ~current_umask();
 176
 177         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
 178                                inode->i_mode;
 179
 180         return rc;
 181 }
 182
 183 static int jfs_acl_chmod(struct inode *inode)
 184 {
 185         struct posix_acl *acl, *clone;
 186         int rc;
 187
 188         if (S_ISLNK(inode->i_mode))
 189                 return -EOPNOTSUPP;
 190
 191         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 192         if (IS_ERR(acl) || !acl)
 193                 return PTR_ERR(acl);
 194
 195         clone = posix_acl_clone(acl, GFP_KERNEL);
 196         posix_acl_release(acl);
 197         if (!clone)
 198                 return -ENOMEM;
 199
 200         rc = posix_acl_chmod_masq(clone, inode->i_mode);
 201         if (!rc) {
 202                 tid_t tid = txBegin(inode->i_sb, 0);
 203                 mutex_lock(&JFS_IP(inode)->commit_mutex);
 204                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
 205                 if (!rc)
 206                         rc = txCommit(tid, 1, &inode, 0);
 207                 txEnd(tid);
 208                 mutex_unlock(&JFS_IP(inode)->commit_mutex);
 209         }
 210
 211         posix_acl_release(clone);
 212         return rc;
 213 }
 214
 215 int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
 216 {
 217         struct inode *inode = dentry->d_inode;
 218         int rc;
 219
 220         rc = inode_change_ok(inode, iattr);
 221         if (rc)
 222                 return rc;
 223
 224         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 225             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 226                 if (vfs_dq_transfer(inode, iattr))
 227                         return -EDQUOT;
 228         }
 229
 230         rc = inode_setattr(inode, iattr);
 231
 232         if (!rc && (iattr->ia_valid & ATTR_MODE))
 233                 rc = jfs_acl_chmod(inode);
 234
 235         return rc;
 236 }