/*
   *   Copyright (C) International Business Machines  Corp., 2002-2004
   *   Copyright (C) Andreas Gruenbacher, 2001
   *   Copyright (C) Linus Torvalds, 1991, 1992
   *
   *   This program is free software;  you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by

   *   the Free Software Foundation; either version 2 of the License, or

   *   (at your option) any later version.

   *

   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   *   the GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License

   *   along with this program;  if not, write to the Free Software

   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  #include <linux/sched.h>
  #include <linux/fs.h>
  #include <linux/quotaops.h>

  #include <linux/posix_acl_xattr.h>

  #include "jfs_incore.h"

  #include "jfs_txnmgr.h"

  #include "jfs_xattr.h"
  #include "jfs_acl.h"
  
  static struct posix_acl *jfs_get_acl(struct inode *inode, int type)
  {
  	struct posix_acl *acl;
  	char *ea_name;
  	struct jfs_inode_info *ji = JFS_IP(inode);
  	struct posix_acl **p_acl;
  	int size;
  	char *value = NULL;
  
  	switch(type) {
  		case ACL_TYPE_ACCESS:

  			ea_name = POSIX_ACL_XATTR_ACCESS;

  			p_acl = &ji->i_acl;
  			break;
  		case ACL_TYPE_DEFAULT:

  			ea_name = POSIX_ACL_XATTR_DEFAULT;

  			p_acl = &ji->i_default_acl;
  			break;
  		default:
  			return ERR_PTR(-EINVAL);
  	}
  
  	if (*p_acl != JFS_ACL_NOT_CACHED)
  		return posix_acl_dup(*p_acl);
  
  	size = __jfs_getxattr(inode, ea_name, NULL, 0);
  
  	if (size > 0) {
  		value = kmalloc(size, GFP_KERNEL);
  		if (!value)
  			return ERR_PTR(-ENOMEM);
  		size = __jfs_getxattr(inode, ea_name, value, size);
  	}
  
  	if (size < 0) {
  		if (size == -ENODATA) {
  			*p_acl = NULL;
  			acl = NULL;
  		} else
  			acl = ERR_PTR(size);
  	} else {
  		acl = posix_acl_from_xattr(value, size);
  		if (!IS_ERR(acl))
  			*p_acl = posix_acl_dup(acl);
  	}

  	kfree(value);

  	return acl;
  }

  static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
  		       struct posix_acl *acl)

  {
  	char *ea_name;
  	struct jfs_inode_info *ji = JFS_IP(inode);
  	struct posix_acl **p_acl;
  	int rc;
  	int size = 0;
  	char *value = NULL;
  
  	if (S_ISLNK(inode->i_mode))
  		return -EOPNOTSUPP;
  
  	switch(type) {
  		case ACL_TYPE_ACCESS:

  			ea_name = POSIX_ACL_XATTR_ACCESS;

  			p_acl = &ji->i_acl;
  			break;
  		case ACL_TYPE_DEFAULT:

  			ea_name = POSIX_ACL_XATTR_DEFAULT;

  			p_acl = &ji->i_default_acl;
  			if (!S_ISDIR(inode->i_mode))
  				return acl ? -EACCES : 0;
  			break;
  		default:
  			return -EINVAL;
  	}
  	if (acl) {

  		size = posix_acl_xattr_size(acl->a_count);

  		value = kmalloc(size, GFP_KERNEL);
  		if (!value)
  			return -ENOMEM;
  		rc = posix_acl_to_xattr(acl, value, size);
  		if (rc < 0)
  			goto out;
  	}

  	rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);

  out:

  	kfree(value);

  
  	if (!rc) {
  		if (*p_acl && (*p_acl != JFS_ACL_NOT_CACHED))
  			posix_acl_release(*p_acl);
  		*p_acl = posix_acl_dup(acl);
  	}
  	return rc;
  }
  
  static int jfs_check_acl(struct inode *inode, int mask)
  {
  	struct jfs_inode_info *ji = JFS_IP(inode);
  
  	if (ji->i_acl == JFS_ACL_NOT_CACHED) {
  		struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
  		if (IS_ERR(acl))
  			return PTR_ERR(acl);
  		posix_acl_release(acl);
  	}
  
  	if (ji->i_acl)
  		return posix_acl_permission(inode, ji->i_acl, mask);
  	return -EAGAIN;
  }
  
  int jfs_permission(struct inode *inode, int mask, struct nameidata *nd)
  {
  	return generic_permission(inode, mask, jfs_check_acl);
  }

  int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)

  {
  	struct posix_acl *acl = NULL;
  	struct posix_acl *clone;
  	mode_t mode;
  	int rc = 0;
  
  	if (S_ISLNK(inode->i_mode))
  		return 0;
  
  	acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
  	if (IS_ERR(acl))
  		return PTR_ERR(acl);
  
  	if (acl) {
  		if (S_ISDIR(inode->i_mode)) {

  			rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);

  			if (rc)
  				goto cleanup;
  		}
  		clone = posix_acl_clone(acl, GFP_KERNEL);
  		if (!clone) {
  			rc = -ENOMEM;
  			goto cleanup;
  		}
  		mode = inode->i_mode;
  		rc = posix_acl_create_masq(clone, &mode);
  		if (rc >= 0) {
  			inode->i_mode = mode;
  			if (rc > 0)

  				rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
  						 clone);

  		}
  		posix_acl_release(clone);
  cleanup:
  		posix_acl_release(acl);
  	} else
  		inode->i_mode &= ~current->fs->umask;

  	JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
  			       inode->i_mode;

  
  	return rc;
  }
  
  static int jfs_acl_chmod(struct inode *inode)
  {
  	struct posix_acl *acl, *clone;
  	int rc;
  
  	if (S_ISLNK(inode->i_mode))
  		return -EOPNOTSUPP;
  
  	acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
  	if (IS_ERR(acl) || !acl)
  		return PTR_ERR(acl);
  
  	clone = posix_acl_clone(acl, GFP_KERNEL);
  	posix_acl_release(acl);
  	if (!clone)
  		return -ENOMEM;
  
  	rc = posix_acl_chmod_masq(clone, inode->i_mode);

  	if (!rc) {
  		tid_t tid = txBegin(inode->i_sb, 0);

  		mutex_lock(&JFS_IP(inode)->commit_mutex);

  		rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
  		if (!rc)
  			rc = txCommit(tid, 1, &inode, 0);
  		txEnd(tid);

  		mutex_unlock(&JFS_IP(inode)->commit_mutex);

  	}

  
  	posix_acl_release(clone);
  	return rc;
  }
  
  int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
  {
  	struct inode *inode = dentry->d_inode;
  	int rc;
  
  	rc = inode_change_ok(inode, iattr);
  	if (rc)
  		return rc;
  
  	if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
  	    (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
  		if (DQUOT_TRANSFER(inode, iattr))
  			return -EDQUOT;
  	}
  
  	rc = inode_setattr(inode, iattr);
  
  	if (!rc && (iattr->ia_valid & ATTR_MODE))
  		rc = jfs_acl_chmod(inode);
  
  	return rc;
  }