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         struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 122
 123         if (IS_ERR(acl))
 124                 return PTR_ERR(acl);
 125         if (acl) {
 126                 int error = posix_acl_permission(inode, acl, mask);
 127                 posix_acl_release(acl);
 128                 return error;
 129         }
 130
 131         return -EAGAIN;
 132 }
 133
 134 int jfs_permission(struct inode *inode, int mask)
 135 {
 136         return generic_permission(inode, mask, jfs_check_acl);
 137 }
 138
 139 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 140 {
 141         struct posix_acl *acl = NULL;
 142         struct posix_acl *clone;
 143         mode_t mode;
 144         int rc = 0;
 145
 146         if (S_ISLNK(inode->i_mode))
 147                 return 0;
 148
 149         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 150         if (IS_ERR(acl))
 151                 return PTR_ERR(acl);
 152
 153         if (acl) {
 154                 if (S_ISDIR(inode->i_mode)) {
 155                         rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
 156                         if (rc)
 157                                 goto cleanup;
 158                 }
 159                 clone = posix_acl_clone(acl, GFP_KERNEL);
 160                 if (!clone) {
 161                         rc = -ENOMEM;
 162                         goto cleanup;
 163                 }
 164                 mode = inode->i_mode;
 165                 rc = posix_acl_create_masq(clone, &mode);
 166                 if (rc >= 0) {
 167                         inode->i_mode = mode;
 168                         if (rc > 0)
 169                                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
 170                                                  clone);
 171                 }
 172                 posix_acl_release(clone);
 173 cleanup:
 174                 posix_acl_release(acl);
 175         } else
 176                 inode->i_mode &= ~current_umask();
 177
 178         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
 179                                inode->i_mode;
 180
 181         return rc;
 182 }
 183
 184 static int jfs_acl_chmod(struct inode *inode)
 185 {
 186         struct posix_acl *acl, *clone;
 187         int rc;
 188
 189         if (S_ISLNK(inode->i_mode))
 190                 return -EOPNOTSUPP;
 191
 192         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 193         if (IS_ERR(acl) || !acl)
 194                 return PTR_ERR(acl);
 195
 196         clone = posix_acl_clone(acl, GFP_KERNEL);
 197         posix_acl_release(acl);
 198         if (!clone)
 199                 return -ENOMEM;
 200
 201         rc = posix_acl_chmod_masq(clone, inode->i_mode);
 202         if (!rc) {
 203                 tid_t tid = txBegin(inode->i_sb, 0);
 204                 mutex_lock(&JFS_IP(inode)->commit_mutex);
 205                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
 206                 if (!rc)
 207                         rc = txCommit(tid, 1, &inode, 0);
 208                 txEnd(tid);
 209                 mutex_unlock(&JFS_IP(inode)->commit_mutex);
 210         }
 211
 212         posix_acl_release(clone);
 213         return rc;
 214 }
 215
 216 int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
 217 {
 218         struct inode *inode = dentry->d_inode;
 219         int rc;
 220
 221         rc = inode_change_ok(inode, iattr);
 222         if (rc)
 223                 return rc;
 224
 225         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 226             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 227                 if (vfs_dq_transfer(inode, iattr))
 228                         return -EDQUOT;
 229         }
 230
 231         rc = inode_setattr(inode, iattr);
 232
 233         if (!rc && (iattr->ia_valid & ATTR_MODE))
 234                 rc = jfs_acl_chmod(inode);
 235
 236         return rc;
 237 }