/*
   * linux/fs/ext2/ioctl.c
   *
   * Copyright (C) 1993, 1994, 1995
   * Remy Card (card@masi.ibp.fr)
   * Laboratoire MASI - Institut Blaise Pascal
   * Universite Pierre et Marie Curie (Paris VI)
   */
  
  #include "ext2.h"

  #include <linux/capability.h>

  #include <linux/time.h>
  #include <linux/sched.h>

  #include <linux/compat.h>

  #include <linux/mount.h>

  #include <asm/current.h>
  #include <asm/uaccess.h>

  long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

  {

  	struct inode *inode = filp->f_dentry->d_inode;

  	struct ext2_inode_info *ei = EXT2_I(inode);
  	unsigned int flags;

  	unsigned short rsv_window_size;

  	int ret;

  
  	ext2_debug ("cmd = %u, arg = %lu
  ", cmd, arg);
  
  	switch (cmd) {
  	case EXT2_IOC_GETFLAGS:

  		ext2_get_inode_flags(ei);

  		flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  		return put_user(flags, (int __user *) arg);
  	case EXT2_IOC_SETFLAGS: {
  		unsigned int oldflags;

  		ret = mnt_want_write_file(filp);

  		if (ret)
  			return ret;

  		if (!inode_owner_or_capable(inode)) {

  			ret = -EACCES;
  			goto setflags_out;
  		}

  		if (get_user(flags, (int __user *) arg)) {
  			ret = -EFAULT;
  			goto setflags_out;
  		}

  		flags = ext2_mask_flags(inode->i_mode, flags);

  		mutex_lock(&inode->i_mutex);

  		/* Is it quota file? Do not allow user to mess with it */
  		if (IS_NOQUOTA(inode)) {
  			mutex_unlock(&inode->i_mutex);

  			ret = -EPERM;
  			goto setflags_out;

  		}

  		oldflags = ei->i_flags;
  
  		/*
  		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  		 * the relevant capability.
  		 *
  		 * This test looks nicer. Thanks to Pauline Middelink
  		 */
  		if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {

  			if (!capable(CAP_LINUX_IMMUTABLE)) {
  				mutex_unlock(&inode->i_mutex);

  				ret = -EPERM;
  				goto setflags_out;

  			}

  		}
  
  		flags = flags & EXT2_FL_USER_MODIFIABLE;
  		flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  		ei->i_flags = flags;

  		mutex_unlock(&inode->i_mutex);

  
  		ext2_set_inode_flags(inode);
  		inode->i_ctime = CURRENT_TIME_SEC;
  		mark_inode_dirty(inode);

  setflags_out:

  		mnt_drop_write_file(filp);

  		return ret;

  	}
  	case EXT2_IOC_GETVERSION:
  		return put_user(inode->i_generation, (int __user *) arg);
  	case EXT2_IOC_SETVERSION:

  		if (!inode_owner_or_capable(inode))

  			return -EPERM;

  		ret = mnt_want_write_file(filp);

  		if (ret)
  			return ret;
  		if (get_user(inode->i_generation, (int __user *) arg)) {
  			ret = -EFAULT;
  		} else {
  			inode->i_ctime = CURRENT_TIME_SEC;
  			mark_inode_dirty(inode);
  		}

  		mnt_drop_write_file(filp);

  		return ret;

  	case EXT2_IOC_GETRSVSZ:
  		if (test_opt(inode->i_sb, RESERVATION)
  			&& S_ISREG(inode->i_mode)
  			&& ei->i_block_alloc_info) {
  			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
  			return put_user(rsv_window_size, (int __user *)arg);
  		}
  		return -ENOTTY;
  	case EXT2_IOC_SETRSVSZ: {
  
  		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
  			return -ENOTTY;

  		if (!inode_owner_or_capable(inode))

  			return -EACCES;
  
  		if (get_user(rsv_window_size, (int __user *)arg))
  			return -EFAULT;

  		ret = mnt_want_write_file(filp);

  		if (ret)
  			return ret;

  		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
  			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
  
  		/*
  		 * need to allocate reservation structure for this inode
  		 * before set the window size
  		 */
  		/*
  		 * XXX What lock should protect the rsv_goal_size?
  		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
  		 */
  		mutex_lock(&ei->truncate_mutex);
  		if (!ei->i_block_alloc_info)
  			ext2_init_block_alloc_info(inode);
  
  		if (ei->i_block_alloc_info){
  			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
  			rsv->rsv_goal_size = rsv_window_size;
  		}
  		mutex_unlock(&ei->truncate_mutex);

  		mnt_drop_write_file(filp);

  		return 0;
  	}

  	default:
  		return -ENOTTY;
  	}
  }

  
  #ifdef CONFIG_COMPAT
  long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {

  	/* These are just misnamed, they actually get/put from/to user an int */
  	switch (cmd) {
  	case EXT2_IOC32_GETFLAGS:
  		cmd = EXT2_IOC_GETFLAGS;
  		break;
  	case EXT2_IOC32_SETFLAGS:
  		cmd = EXT2_IOC_SETFLAGS;
  		break;
  	case EXT2_IOC32_GETVERSION:
  		cmd = EXT2_IOC_GETVERSION;
  		break;
  	case EXT2_IOC32_SETVERSION:
  		cmd = EXT2_IOC_SETVERSION;
  		break;
  	default:
  		return -ENOIOCTLCMD;
  	}

  	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));

  }
  #endif