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         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(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 static int jfs_check_acl(struct inode *inode, int mask)
 118 {
 119         struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 120
 121         if (IS_ERR(acl))
 122                 return PTR_ERR(acl);
 123         if (acl) {
 124                 int error = posix_acl_permission(inode, acl, mask);
 125                 posix_acl_release(acl);
 126                 return error;
 127         }
 128
 129         return -EAGAIN;
 130 }
 131
 132 int jfs_permission(struct inode *inode, int mask)
 133 {
 134         return generic_permission(inode, mask, jfs_check_acl);
 135 }
 136
 137 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
 138 {
 139         struct posix_acl *acl = NULL;
 140         struct posix_acl *clone;
 141         mode_t mode;
 142         int rc = 0;
 143
 144         if (S_ISLNK(inode->i_mode))
 145                 return 0;
 146
 147         acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
 148         if (IS_ERR(acl))
 149                 return PTR_ERR(acl);
 150
 151         if (acl) {
 152                 if (S_ISDIR(inode->i_mode)) {
 153                         rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
 154                         if (rc)
 155                                 goto cleanup;
 156                 }
 157                 clone = posix_acl_clone(acl, GFP_KERNEL);
 158                 if (!clone) {
 159                         rc = -ENOMEM;
 160                         goto cleanup;
 161                 }
 162                 mode = inode->i_mode;
 163                 rc = posix_acl_create_masq(clone, &mode);
 164                 if (rc >= 0) {
 165                         inode->i_mode = mode;
 166                         if (rc > 0)
 167                                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
 168                                                  clone);
 169                 }
 170                 posix_acl_release(clone);
 171 cleanup:
 172                 posix_acl_release(acl);
 173         } else
 174                 inode->i_mode &= ~current_umask();
 175
 176         JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
 177                                inode->i_mode;
 178
 179         return rc;
 180 }
 181
 182 static int jfs_acl_chmod(struct inode *inode)
 183 {
 184         struct posix_acl *acl, *clone;
 185         int rc;
 186
 187         if (S_ISLNK(inode->i_mode))
 188                 return -EOPNOTSUPP;
 189
 190         acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
 191         if (IS_ERR(acl) || !acl)
 192                 return PTR_ERR(acl);
 193
 194         clone = posix_acl_clone(acl, GFP_KERNEL);
 195         posix_acl_release(acl);
 196         if (!clone)
 197                 return -ENOMEM;
 198
 199         rc = posix_acl_chmod_masq(clone, inode->i_mode);
 200         if (!rc) {
 201                 tid_t tid = txBegin(inode->i_sb, 0);
 202                 mutex_lock(&JFS_IP(inode)->commit_mutex);
 203                 rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
 204                 if (!rc)
 205                         rc = txCommit(tid, 1, &inode, 0);
 206                 txEnd(tid);
 207                 mutex_unlock(&JFS_IP(inode)->commit_mutex);
 208         }
 209
 210         posix_acl_release(clone);
 211         return rc;
 212 }
 213
 214 int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
 215 {
 216         struct inode *inode = dentry->d_inode;
 217         int rc;
 218
 219         rc = inode_change_ok(inode, iattr);
 220         if (rc)
 221                 return rc;
 222
 223         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 224             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 225                 if (vfs_dq_transfer(inode, iattr))
 226                         return -EDQUOT;
 227         }
 228
 229         rc = inode_setattr(inode, iattr);
 230
 231         if (!rc && (iattr->ia_valid & ATTR_MODE))
 232                 rc = jfs_acl_chmod(inode);
 233
 234         return rc;
 235 }