/*
   * This file is part of UBIFS.
   *
   * Copyright (C) 2006-2008 Nokia Corporation.
   * Copyright (C) 2006, 2007 University of Szeged, Hungary
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * 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., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
   *
   * Authors: Zoltan Sogor
   *          Artem Bityutskiy (Битюцкий Артём)
   *          Adrian Hunter
   */
  
  /* This file implements EXT2-compatible extended attribute ioctl() calls */
  
  #include <linux/compat.h>
  #include <linux/mount.h>
  #include "ubifs.h"
  
  /**
   * ubifs_set_inode_flags - set VFS inode flags.
   * @inode: VFS inode to set flags for
   *
   * This function propagates flags from UBIFS inode object to VFS inode object.
   */
  void ubifs_set_inode_flags(struct inode *inode)
  {
  	unsigned int flags = ubifs_inode(inode)->flags;
  
  	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
  	if (flags & UBIFS_SYNC_FL)
  		inode->i_flags |= S_SYNC;
  	if (flags & UBIFS_APPEND_FL)
  		inode->i_flags |= S_APPEND;
  	if (flags & UBIFS_IMMUTABLE_FL)
  		inode->i_flags |= S_IMMUTABLE;
  	if (flags & UBIFS_DIRSYNC_FL)
  		inode->i_flags |= S_DIRSYNC;
  }
  
  /*
   * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
   * @ioctl_flags: flags to convert
   *
   * This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
   * (@UBIFS_COMPR_FL, etc).
   */
  static int ioctl2ubifs(int ioctl_flags)
  {
  	int ubifs_flags = 0;
  
  	if (ioctl_flags & FS_COMPR_FL)
  		ubifs_flags |= UBIFS_COMPR_FL;
  	if (ioctl_flags & FS_SYNC_FL)
  		ubifs_flags |= UBIFS_SYNC_FL;
  	if (ioctl_flags & FS_APPEND_FL)
  		ubifs_flags |= UBIFS_APPEND_FL;
  	if (ioctl_flags & FS_IMMUTABLE_FL)
  		ubifs_flags |= UBIFS_IMMUTABLE_FL;
  	if (ioctl_flags & FS_DIRSYNC_FL)
  		ubifs_flags |= UBIFS_DIRSYNC_FL;
  
  	return ubifs_flags;
  }
  
  /*
   * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
   * @ubifs_flags: flags to convert
   *
   * This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
   * (@FS_COMPR_FL, etc).
   */
  static int ubifs2ioctl(int ubifs_flags)
  {
  	int ioctl_flags = 0;
  
  	if (ubifs_flags & UBIFS_COMPR_FL)
  		ioctl_flags |= FS_COMPR_FL;
  	if (ubifs_flags & UBIFS_SYNC_FL)
  		ioctl_flags |= FS_SYNC_FL;
  	if (ubifs_flags & UBIFS_APPEND_FL)
  		ioctl_flags |= FS_APPEND_FL;
  	if (ubifs_flags & UBIFS_IMMUTABLE_FL)
  		ioctl_flags |= FS_IMMUTABLE_FL;
  	if (ubifs_flags & UBIFS_DIRSYNC_FL)
  		ioctl_flags |= FS_DIRSYNC_FL;
  
  	return ioctl_flags;
  }
  
  static int setflags(struct inode *inode, int flags)
  {
  	int oldflags, err, release;
  	struct ubifs_inode *ui = ubifs_inode(inode);
  	struct ubifs_info *c = inode->i_sb->s_fs_info;
  	struct ubifs_budget_req req = { .dirtied_ino = 1,
  					.dirtied_ino_d = ui->data_len };
  
  	err = ubifs_budget_space(c, &req);
  	if (err)
  		return err;
  
  	/*
  	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  	 * the relevant capability.
  	 */
  	mutex_lock(&ui->ui_mutex);
  	oldflags = ubifs2ioctl(ui->flags);
  	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
  		if (!capable(CAP_LINUX_IMMUTABLE)) {
  			err = -EPERM;
  			goto out_unlock;
  		}
  	}
  
  	ui->flags = ioctl2ubifs(flags);
  	ubifs_set_inode_flags(inode);
  	inode->i_ctime = ubifs_current_time(inode);
  	release = ui->dirty;
  	mark_inode_dirty_sync(inode);
  	mutex_unlock(&ui->ui_mutex);
  
  	if (release)
  		ubifs_release_budget(c, &req);
  	if (IS_SYNC(inode))
  		err = write_inode_now(inode, 1);
  	return err;
  
  out_unlock:
  	ubifs_err(c, "can't modify inode %lu attributes", inode->i_ino);
  	mutex_unlock(&ui->ui_mutex);
  	ubifs_release_budget(c, &req);
  	return err;
  }
  
  long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	int flags, err;
  	struct inode *inode = file_inode(file);
  
  	switch (cmd) {
  	case FS_IOC_GETFLAGS:
  		flags = ubifs2ioctl(ubifs_inode(inode)->flags);
  
  		dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
  		return put_user(flags, (int __user *) arg);
  
  	case FS_IOC_SETFLAGS: {
  		if (IS_RDONLY(inode))
  			return -EROFS;
  
  		if (!inode_owner_or_capable(inode))
  			return -EACCES;
  
  		if (get_user(flags, (int __user *) arg))
  			return -EFAULT;
  
  		if (!S_ISDIR(inode->i_mode))
  			flags &= ~FS_DIRSYNC_FL;
  
  		/*
  		 * Make sure the file-system is read-write and make sure it
  		 * will not become read-only while we are changing the flags.
  		 */
  		err = mnt_want_write_file(file);
  		if (err)
  			return err;
  		dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
  		err = setflags(inode, flags);
  		mnt_drop_write_file(file);
  		return err;
  	}
  
  	default:
  		return -ENOTTY;
  	}
  }
  
  #ifdef CONFIG_COMPAT
  long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	switch (cmd) {
  	case FS_IOC32_GETFLAGS:
  		cmd = FS_IOC_GETFLAGS;
  		break;
  	case FS_IOC32_SETFLAGS:
  		cmd = FS_IOC_SETFLAGS;
  		break;
  	default:
  		return -ENOIOCTLCMD;
  	}
  	return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
  }
  #endif