/*

   * linux/fs/ext4/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 <linux/fs.h>

  #include <linux/capability.h>

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

  #include <linux/mount.h>

  #include <linux/file.h>

  #include <linux/quotaops.h>

  #include <linux/uuid.h>

  #include <asm/uaccess.h>

  #include "ext4_jbd2.h"
  #include "ext4.h"

  /**
   * Swap memory between @a and @b for @len bytes.
   *
   * @a:          pointer to first memory area
   * @b:          pointer to second memory area
   * @len:        number of bytes to swap
   *
   */
  static void memswap(void *a, void *b, size_t len)
  {
  	unsigned char *ap, *bp;

  
  	ap = (unsigned char *)a;
  	bp = (unsigned char *)b;
  	while (len-- > 0) {

  		swap(*ap, *bp);

  		ap++;
  		bp++;
  	}
  }
  
  /**
   * Swap i_data and associated attributes between @inode1 and @inode2.
   * This function is used for the primary swap between inode1 and inode2
   * and also to revert this primary swap in case of errors.
   *
   * Therefore you have to make sure, that calling this method twice
   * will revert all changes.
   *
   * @inode1:     pointer to first inode
   * @inode2:     pointer to second inode
   */
  static void swap_inode_data(struct inode *inode1, struct inode *inode2)
  {
  	loff_t isize;
  	struct ext4_inode_info *ei1;
  	struct ext4_inode_info *ei2;
  
  	ei1 = EXT4_I(inode1);
  	ei2 = EXT4_I(inode2);
  
  	memswap(&inode1->i_flags, &inode2->i_flags, sizeof(inode1->i_flags));
  	memswap(&inode1->i_version, &inode2->i_version,
  		  sizeof(inode1->i_version));
  	memswap(&inode1->i_blocks, &inode2->i_blocks,
  		  sizeof(inode1->i_blocks));
  	memswap(&inode1->i_bytes, &inode2->i_bytes, sizeof(inode1->i_bytes));
  	memswap(&inode1->i_atime, &inode2->i_atime, sizeof(inode1->i_atime));
  	memswap(&inode1->i_mtime, &inode2->i_mtime, sizeof(inode1->i_mtime));
  
  	memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
  	memswap(&ei1->i_flags, &ei2->i_flags, sizeof(ei1->i_flags));
  	memswap(&ei1->i_disksize, &ei2->i_disksize, sizeof(ei1->i_disksize));

  	ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
  	ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);

  
  	isize = i_size_read(inode1);
  	i_size_write(inode1, i_size_read(inode2));
  	i_size_write(inode2, isize);
  }
  
  /**
   * Swap the information from the given @inode and the inode
   * EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
   * important fields of the inodes.
   *
   * @sb:         the super block of the filesystem
   * @inode:      the inode to swap with EXT4_BOOT_LOADER_INO
   *
   */
  static long swap_inode_boot_loader(struct super_block *sb,
  				struct inode *inode)
  {
  	handle_t *handle;
  	int err;
  	struct inode *inode_bl;

  	struct ext4_inode_info *ei_bl;

  	struct ext4_sb_info *sbi = EXT4_SB(sb);

  	if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode))
  		return -EINVAL;

  	if (!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))
  		return -EPERM;

  	inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);

  	if (IS_ERR(inode_bl))
  		return PTR_ERR(inode_bl);

  	ei_bl = EXT4_I(inode_bl);
  
  	filemap_flush(inode->i_mapping);
  	filemap_flush(inode_bl->i_mapping);
  
  	/* Protect orig inodes against a truncate and make sure,
  	 * that only 1 swap_inode_boot_loader is running. */

  	lock_two_nondirectories(inode, inode_bl);

  
  	truncate_inode_pages(&inode->i_data, 0);
  	truncate_inode_pages(&inode_bl->i_data, 0);
  
  	/* Wait for all existing dio workers */
  	ext4_inode_block_unlocked_dio(inode);
  	ext4_inode_block_unlocked_dio(inode_bl);
  	inode_dio_wait(inode);
  	inode_dio_wait(inode_bl);
  
  	handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
  	if (IS_ERR(handle)) {
  		err = -EINVAL;

  		goto journal_err_out;

  	}
  
  	/* Protect extent tree against block allocations via delalloc */
  	ext4_double_down_write_data_sem(inode, inode_bl);
  
  	if (inode_bl->i_nlink == 0) {
  		/* this inode has never been used as a BOOT_LOADER */
  		set_nlink(inode_bl, 1);
  		i_uid_write(inode_bl, 0);
  		i_gid_write(inode_bl, 0);
  		inode_bl->i_flags = 0;
  		ei_bl->i_flags = 0;
  		inode_bl->i_version = 1;
  		i_size_write(inode_bl, 0);
  		inode_bl->i_mode = S_IFREG;

  		if (ext4_has_feature_extents(sb)) {

  			ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
  			ext4_ext_tree_init(handle, inode_bl);
  		} else
  			memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
  	}
  
  	swap_inode_data(inode, inode_bl);
  
  	inode->i_ctime = inode_bl->i_ctime = ext4_current_time(inode);
  
  	spin_lock(&sbi->s_next_gen_lock);
  	inode->i_generation = sbi->s_next_generation++;
  	inode_bl->i_generation = sbi->s_next_generation++;
  	spin_unlock(&sbi->s_next_gen_lock);
  
  	ext4_discard_preallocations(inode);
  
  	err = ext4_mark_inode_dirty(handle, inode);
  	if (err < 0) {
  		ext4_warning(inode->i_sb,
  			"couldn't mark inode #%lu dirty (err %d)",
  			inode->i_ino, err);
  		/* Revert all changes: */
  		swap_inode_data(inode, inode_bl);
  	} else {
  		err = ext4_mark_inode_dirty(handle, inode_bl);
  		if (err < 0) {
  			ext4_warning(inode_bl->i_sb,
  				"couldn't mark inode #%lu dirty (err %d)",
  				inode_bl->i_ino, err);
  			/* Revert all changes: */
  			swap_inode_data(inode, inode_bl);
  			ext4_mark_inode_dirty(handle, inode);
  		}
  	}

  	ext4_journal_stop(handle);

  	ext4_double_up_write_data_sem(inode, inode_bl);

  journal_err_out:

  	ext4_inode_resume_unlocked_dio(inode);
  	ext4_inode_resume_unlocked_dio(inode_bl);

  	unlock_two_nondirectories(inode, inode_bl);

  	iput(inode_bl);

  	return err;
  }

  static int uuid_is_zero(__u8 u[16])
  {
  	int	i;
  
  	for (i = 0; i < 16; i++)
  		if (u[i])
  			return 0;
  	return 1;
  }

  static int ext4_ioctl_setflags(struct inode *inode,
  			       unsigned int flags)
  {
  	struct ext4_inode_info *ei = EXT4_I(inode);
  	handle_t *handle = NULL;

  	int err = -EPERM, migrate = 0;

  	struct ext4_iloc iloc;
  	unsigned int oldflags, mask, i;
  	unsigned int jflag;
  
  	/* Is it quota file? Do not allow user to mess with it */
  	if (IS_NOQUOTA(inode))
  		goto flags_out;
  
  	oldflags = ei->i_flags;
  
  	/* The JOURNAL_DATA flag is modifiable only by root */
  	jflag = flags & EXT4_JOURNAL_DATA_FL;
  
  	/*
  	 * 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) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  		if (!capable(CAP_LINUX_IMMUTABLE))
  			goto flags_out;
  	}
  
  	/*
  	 * The JOURNAL_DATA flag can only be changed by
  	 * the relevant capability.
  	 */
  	if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  		if (!capable(CAP_SYS_RESOURCE))
  			goto flags_out;
  	}
  	if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
  		migrate = 1;
  
  	if (flags & EXT4_EOFBLOCKS_FL) {
  		/* we don't support adding EOFBLOCKS flag */
  		if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
  			err = -EOPNOTSUPP;
  			goto flags_out;
  		}
  	} else if (oldflags & EXT4_EOFBLOCKS_FL)
  		ext4_truncate(inode);
  
  	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
  	if (IS_ERR(handle)) {
  		err = PTR_ERR(handle);
  		goto flags_out;
  	}
  	if (IS_SYNC(inode))
  		ext4_handle_sync(handle);
  	err = ext4_reserve_inode_write(handle, inode, &iloc);
  	if (err)
  		goto flags_err;
  
  	for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
  		if (!(mask & EXT4_FL_USER_MODIFIABLE))
  			continue;
  		if (mask & flags)
  			ext4_set_inode_flag(inode, i);
  		else
  			ext4_clear_inode_flag(inode, i);
  	}
  
  	ext4_set_inode_flags(inode);
  	inode->i_ctime = ext4_current_time(inode);
  
  	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
  flags_err:
  	ext4_journal_stop(handle);
  	if (err)
  		goto flags_out;
  
  	if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
  		err = ext4_change_inode_journal_flag(inode, jflag);
  	if (err)
  		goto flags_out;
  	if (migrate) {
  		if (flags & EXT4_EXTENTS_FL)
  			err = ext4_ext_migrate(inode);
  		else
  			err = ext4_ind_migrate(inode);
  	}
  
  flags_out:
  	return err;
  }
  
  #ifdef CONFIG_QUOTA
  static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
  {
  	struct inode *inode = file_inode(filp);
  	struct super_block *sb = inode->i_sb;
  	struct ext4_inode_info *ei = EXT4_I(inode);
  	int err, rc;
  	handle_t *handle;
  	kprojid_t kprojid;
  	struct ext4_iloc iloc;
  	struct ext4_inode *raw_inode;

  	struct dquot *transfer_to[MAXQUOTAS] = { };

  	if (!ext4_has_feature_project(sb)) {

  		if (projid != EXT4_DEF_PROJID)
  			return -EOPNOTSUPP;
  		else
  			return 0;
  	}
  
  	if (EXT4_INODE_SIZE(sb) <= EXT4_GOOD_OLD_INODE_SIZE)
  		return -EOPNOTSUPP;
  
  	kprojid = make_kprojid(&init_user_ns, (projid_t)projid);
  
  	if (projid_eq(kprojid, EXT4_I(inode)->i_projid))
  		return 0;
  
  	err = mnt_want_write_file(filp);
  	if (err)
  		return err;
  
  	err = -EPERM;

  	inode_lock(inode);

  	/* Is it quota file? Do not allow user to mess with it */
  	if (IS_NOQUOTA(inode))
  		goto out_unlock;
  
  	err = ext4_get_inode_loc(inode, &iloc);
  	if (err)
  		goto out_unlock;
  
  	raw_inode = ext4_raw_inode(&iloc);
  	if (!EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) {
  		err = -EOVERFLOW;
  		brelse(iloc.bh);
  		goto out_unlock;
  	}
  	brelse(iloc.bh);
  
  	dquot_initialize(inode);
  
  	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
  		EXT4_QUOTA_INIT_BLOCKS(sb) +
  		EXT4_QUOTA_DEL_BLOCKS(sb) + 3);
  	if (IS_ERR(handle)) {
  		err = PTR_ERR(handle);
  		goto out_unlock;
  	}
  
  	err = ext4_reserve_inode_write(handle, inode, &iloc);
  	if (err)
  		goto out_stop;

  	transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
  	if (!IS_ERR(transfer_to[PRJQUOTA])) {
  		err = __dquot_transfer(inode, transfer_to);
  		dqput(transfer_to[PRJQUOTA]);
  		if (err)
  			goto out_dirty;

  	}

  	EXT4_I(inode)->i_projid = kprojid;
  	inode->i_ctime = ext4_current_time(inode);
  out_dirty:
  	rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
  	if (!err)
  		err = rc;
  out_stop:
  	ext4_journal_stop(handle);
  out_unlock:

  	inode_unlock(inode);

  	mnt_drop_write_file(filp);
  	return err;
  }
  #else
  static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
  {
  	if (projid != EXT4_DEF_PROJID)
  		return -EOPNOTSUPP;
  	return 0;
  }
  #endif
  
  /* Transfer internal flags to xflags */
  static inline __u32 ext4_iflags_to_xflags(unsigned long iflags)
  {
  	__u32 xflags = 0;
  
  	if (iflags & EXT4_SYNC_FL)
  		xflags |= FS_XFLAG_SYNC;
  	if (iflags & EXT4_IMMUTABLE_FL)
  		xflags |= FS_XFLAG_IMMUTABLE;
  	if (iflags & EXT4_APPEND_FL)
  		xflags |= FS_XFLAG_APPEND;
  	if (iflags & EXT4_NODUMP_FL)
  		xflags |= FS_XFLAG_NODUMP;
  	if (iflags & EXT4_NOATIME_FL)
  		xflags |= FS_XFLAG_NOATIME;
  	if (iflags & EXT4_PROJINHERIT_FL)
  		xflags |= FS_XFLAG_PROJINHERIT;
  	return xflags;
  }
  
  /* Transfer xflags flags to internal */
  static inline unsigned long ext4_xflags_to_iflags(__u32 xflags)
  {
  	unsigned long iflags = 0;
  
  	if (xflags & FS_XFLAG_SYNC)
  		iflags |= EXT4_SYNC_FL;
  	if (xflags & FS_XFLAG_IMMUTABLE)
  		iflags |= EXT4_IMMUTABLE_FL;
  	if (xflags & FS_XFLAG_APPEND)
  		iflags |= EXT4_APPEND_FL;
  	if (xflags & FS_XFLAG_NODUMP)
  		iflags |= EXT4_NODUMP_FL;
  	if (xflags & FS_XFLAG_NOATIME)
  		iflags |= EXT4_NOATIME_FL;
  	if (xflags & FS_XFLAG_PROJINHERIT)
  		iflags |= EXT4_PROJINHERIT_FL;
  
  	return iflags;
  }

  long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

  {

  	struct inode *inode = file_inode(filp);

  	struct super_block *sb = inode->i_sb;

  	struct ext4_inode_info *ei = EXT4_I(inode);

  	unsigned int flags;

  	ext4_debug("cmd = %u, arg = %lu
  ", cmd, arg);

  
  	switch (cmd) {

  	case EXT4_IOC_GETFLAGS:

  		ext4_get_inode_flags(ei);

  		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;

  		return put_user(flags, (int __user *) arg);

  	case EXT4_IOC_SETFLAGS: {

  		int err;

  		if (!inode_owner_or_capable(inode))

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

  		err = mnt_want_write_file(filp);

  		if (err)
  			return err;

  		flags = ext4_mask_flags(inode->i_mode, flags);

  		inode_lock(inode);

  		err = ext4_ioctl_setflags(inode, flags);

  		inode_unlock(inode);

  		mnt_drop_write_file(filp);

  		return err;
  	}

  	case EXT4_IOC_GETVERSION:
  	case EXT4_IOC_GETVERSION_OLD:

  		return put_user(inode->i_generation, (int __user *) arg);

  	case EXT4_IOC_SETVERSION:
  	case EXT4_IOC_SETVERSION_OLD: {

  		handle_t *handle;

  		struct ext4_iloc iloc;

  		__u32 generation;
  		int err;

  		if (!inode_owner_or_capable(inode))

  			return -EPERM;

  		if (ext4_has_metadata_csum(inode->i_sb)) {

  			ext4_warning(sb, "Setting inode version is not "
  				     "supported with metadata_csum enabled.");
  			return -ENOTTY;
  		}

  		err = mnt_want_write_file(filp);

  		if (err)
  			return err;
  		if (get_user(generation, (int __user *) arg)) {
  			err = -EFAULT;
  			goto setversion_out;
  		}

  		inode_lock(inode);

  		handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);

  		if (IS_ERR(handle)) {
  			err = PTR_ERR(handle);

  			goto unlock_out;

  		}

  		err = ext4_reserve_inode_write(handle, inode, &iloc);

  		if (err == 0) {

  			inode->i_ctime = ext4_current_time(inode);

  			inode->i_generation = generation;

  			err = ext4_mark_iloc_dirty(handle, inode, &iloc);

  		}

  		ext4_journal_stop(handle);

  
  unlock_out:

  		inode_unlock(inode);

  setversion_out:

  		mnt_drop_write_file(filp);

  		return err;
  	}

  	case EXT4_IOC_GROUP_EXTEND: {
  		ext4_fsblk_t n_blocks_count;

  		int err, err2=0;

  		err = ext4_resize_begin(sb);
  		if (err)
  			return err;

  		if (get_user(n_blocks_count, (__u32 __user *)arg)) {
  			err = -EFAULT;
  			goto group_extend_out;
  		}

  		if (ext4_has_feature_bigalloc(sb)) {

  			ext4_msg(sb, KERN_ERR,
  				 "Online resizing not supported with bigalloc");

  			err = -EOPNOTSUPP;
  			goto group_extend_out;

  		}

  		err = mnt_want_write_file(filp);

  		if (err)

  			goto group_extend_out;

  		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);

  		if (EXT4_SB(sb)->s_journal) {
  			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
  			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
  			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
  		}

  		if (err == 0)
  			err = err2;

  		mnt_drop_write_file(filp);

  group_extend_out:

  		ext4_resize_end(sb);

  		return err;
  	}

  
  	case EXT4_IOC_MOVE_EXT: {
  		struct move_extent me;

  		struct fd donor;
  		int err;

  		if (!(filp->f_mode & FMODE_READ) ||
  		    !(filp->f_mode & FMODE_WRITE))
  			return -EBADF;

  		if (copy_from_user(&me,
  			(struct move_extent __user *)arg, sizeof(me)))
  			return -EFAULT;

  		me.moved_len = 0;

  		donor = fdget(me.donor_fd);
  		if (!donor.file)

  			return -EBADF;

  		if (!(donor.file->f_mode & FMODE_WRITE)) {

  			err = -EBADF;
  			goto mext_out;

  		}

  		if (ext4_has_feature_bigalloc(sb)) {

  			ext4_msg(sb, KERN_ERR,
  				 "Online defrag not supported with bigalloc");

  			err = -EOPNOTSUPP;
  			goto mext_out;

  		} else if (IS_DAX(inode)) {
  			ext4_msg(sb, KERN_ERR,
  				 "Online defrag not supported with DAX");
  			err = -EOPNOTSUPP;
  			goto mext_out;

  		}

  		err = mnt_want_write_file(filp);

  		if (err)
  			goto mext_out;

  		err = ext4_move_extents(filp, donor.file, me.orig_start,

  					me.donor_start, me.len, &me.moved_len);

  		mnt_drop_write_file(filp);

  		if (copy_to_user((struct move_extent __user *)arg,

  				 &me, sizeof(me)))

  			err = -EFAULT;
  mext_out:

  		fdput(donor);

  		return err;
  	}

  	case EXT4_IOC_GROUP_ADD: {
  		struct ext4_new_group_data input;

  		int err, err2=0;

  		err = ext4_resize_begin(sb);
  		if (err)
  			return err;

  		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,

  				sizeof(input))) {
  			err = -EFAULT;
  			goto group_add_out;
  		}

  		if (ext4_has_feature_bigalloc(sb)) {

  			ext4_msg(sb, KERN_ERR,
  				 "Online resizing not supported with bigalloc");

  			err = -EOPNOTSUPP;
  			goto group_add_out;

  		}

  		err = mnt_want_write_file(filp);

  		if (err)

  			goto group_add_out;

  		err = ext4_group_add(sb, &input);

  		if (EXT4_SB(sb)->s_journal) {
  			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
  			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
  			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
  		}

  		if (err == 0)
  			err = err2;

  		mnt_drop_write_file(filp);

  		if (!err && ext4_has_group_desc_csum(sb) &&
  		    test_opt(sb, INIT_INODE_TABLE))
  			err = ext4_register_li_request(sb, input.group);

  group_add_out:

  		ext4_resize_end(sb);

  		return err;
  	}

  	case EXT4_IOC_MIGRATE:

  	{
  		int err;

  		if (!inode_owner_or_capable(inode))

  			return -EACCES;

  		err = mnt_want_write_file(filp);

  		if (err)
  			return err;
  		/*
  		 * inode_mutex prevent write and truncate on the file.
  		 * Read still goes through. We take i_data_sem in
  		 * ext4_ext_swap_inode_data before we switch the
  		 * inode format to prevent read.
  		 */

  		inode_lock((inode));

  		err = ext4_ext_migrate(inode);

  		inode_unlock((inode));

  		mnt_drop_write_file(filp);

  		return err;
  	}

  	case EXT4_IOC_ALLOC_DA_BLKS:
  	{
  		int err;

  		if (!inode_owner_or_capable(inode))

  			return -EACCES;

  		err = mnt_want_write_file(filp);

  		if (err)
  			return err;
  		err = ext4_alloc_da_blocks(inode);

  		mnt_drop_write_file(filp);

  		return err;
  	}

  	case EXT4_IOC_SWAP_BOOT:

  	{
  		int err;

  		if (!(filp->f_mode & FMODE_WRITE))
  			return -EBADF;

  		err = mnt_want_write_file(filp);
  		if (err)
  			return err;
  		err = swap_inode_boot_loader(sb, inode);
  		mnt_drop_write_file(filp);
  		return err;
  	}

  	case EXT4_IOC_RESIZE_FS: {
  		ext4_fsblk_t n_blocks_count;

  		int err = 0, err2 = 0;

  		ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;

  		if (ext4_has_feature_bigalloc(sb)) {

  			ext4_msg(sb, KERN_ERR,
  				 "Online resizing not (yet) supported with bigalloc");
  			return -EOPNOTSUPP;
  		}

  		if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
  				   sizeof(__u64))) {
  			return -EFAULT;
  		}

  		err = ext4_resize_begin(sb);
  		if (err)
  			return err;

  		err = mnt_want_write_file(filp);

  		if (err)
  			goto resizefs_out;
  
  		err = ext4_resize_fs(sb, n_blocks_count);
  		if (EXT4_SB(sb)->s_journal) {
  			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
  			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
  			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
  		}
  		if (err == 0)
  			err = err2;

  		mnt_drop_write_file(filp);

  		if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
  		    ext4_has_group_desc_csum(sb) &&
  		    test_opt(sb, INIT_INODE_TABLE))
  			err = ext4_register_li_request(sb, o_group);

  resizefs_out:
  		ext4_resize_end(sb);
  		return err;
  	}

  	case FITRIM:
  	{

  		struct request_queue *q = bdev_get_queue(sb->s_bdev);

  		struct fstrim_range range;
  		int ret = 0;
  
  		if (!capable(CAP_SYS_ADMIN))
  			return -EPERM;

  		if (!blk_queue_discard(q))
  			return -EOPNOTSUPP;

  		if (copy_from_user(&range, (struct fstrim_range __user *)arg,

  		    sizeof(range)))
  			return -EFAULT;

  		range.minlen = max((unsigned int)range.minlen,
  				   q->limits.discard_granularity);

  		ret = ext4_trim_fs(sb, &range);
  		if (ret < 0)
  			return ret;

  		if (copy_to_user((struct fstrim_range __user *)arg, &range,

  		    sizeof(range)))
  			return -EFAULT;
  
  		return 0;
  	}

  	case EXT4_IOC_PRECACHE_EXTENTS:
  		return ext4_ext_precache(inode);

  	case EXT4_IOC_SET_ENCRYPTION_POLICY: {
  #ifdef CONFIG_EXT4_FS_ENCRYPTION

  		struct fscrypt_policy policy;

  		if (!ext4_has_feature_encrypt(sb))
  			return -EOPNOTSUPP;

  		if (copy_from_user(&policy,

  				   (struct fscrypt_policy __user *)arg,
  				   sizeof(policy)))
  			return -EFAULT;

  		return fscrypt_process_policy(filp, &policy);

  #else
  		return -EOPNOTSUPP;
  #endif
  	}
  	case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
  		int err, err2;
  		struct ext4_sb_info *sbi = EXT4_SB(sb);
  		handle_t *handle;
  
  		if (!ext4_sb_has_crypto(sb))
  			return -EOPNOTSUPP;
  		if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
  			err = mnt_want_write_file(filp);
  			if (err)
  				return err;
  			handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
  			if (IS_ERR(handle)) {
  				err = PTR_ERR(handle);
  				goto pwsalt_err_exit;
  			}
  			err = ext4_journal_get_write_access(handle, sbi->s_sbh);
  			if (err)
  				goto pwsalt_err_journal;
  			generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
  			err = ext4_handle_dirty_metadata(handle, NULL,
  							 sbi->s_sbh);
  		pwsalt_err_journal:
  			err2 = ext4_journal_stop(handle);
  			if (err2 && !err)
  				err = err2;
  		pwsalt_err_exit:
  			mnt_drop_write_file(filp);
  			if (err)
  				return err;
  		}

  		if (copy_to_user((void __user *) arg,
  				 sbi->s_es->s_encrypt_pw_salt, 16))

  			return -EFAULT;
  		return 0;
  	}
  	case EXT4_IOC_GET_ENCRYPTION_POLICY: {
  #ifdef CONFIG_EXT4_FS_ENCRYPTION

  		struct fscrypt_policy policy;

  		int err = 0;
  
  		if (!ext4_encrypted_inode(inode))
  			return -ENOENT;

  		err = fscrypt_get_policy(inode, &policy);

  		if (err)
  			return err;

  		if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))

  			return -EFAULT;
  		return 0;
  #else
  		return -EOPNOTSUPP;
  #endif
  	}

  	case EXT4_IOC_FSGETXATTR:
  	{
  		struct fsxattr fa;
  
  		memset(&fa, 0, sizeof(struct fsxattr));
  		ext4_get_inode_flags(ei);
  		fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE);

  		if (ext4_has_feature_project(inode->i_sb)) {

  			fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
  				EXT4_I(inode)->i_projid);
  		}
  
  		if (copy_to_user((struct fsxattr __user *)arg,
  				 &fa, sizeof(fa)))
  			return -EFAULT;
  		return 0;
  	}
  	case EXT4_IOC_FSSETXATTR:
  	{
  		struct fsxattr fa;
  		int err;
  
  		if (copy_from_user(&fa, (struct fsxattr __user *)arg,
  				   sizeof(fa)))
  			return -EFAULT;
  
  		/* Make sure caller has proper permission */
  		if (!inode_owner_or_capable(inode))
  			return -EACCES;
  
  		err = mnt_want_write_file(filp);
  		if (err)
  			return err;
  
  		flags = ext4_xflags_to_iflags(fa.fsx_xflags);
  		flags = ext4_mask_flags(inode->i_mode, flags);

  		inode_lock(inode);

  		flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |
  			 (flags & EXT4_FL_XFLAG_VISIBLE);
  		err = ext4_ioctl_setflags(inode, flags);

  		inode_unlock(inode);

  		mnt_drop_write_file(filp);
  		if (err)
  			return err;
  
  		err = ext4_ioctl_setproject(filp, fa.fsx_projid);
  		if (err)
  			return err;
  
  		return 0;
  	}

  	default:
  		return -ENOTTY;
  	}
  }
  
  #ifdef CONFIG_COMPAT

  long ext4_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 EXT4_IOC32_GETFLAGS:
  		cmd = EXT4_IOC_GETFLAGS;

  		break;

  	case EXT4_IOC32_SETFLAGS:
  		cmd = EXT4_IOC_SETFLAGS;

  		break;

  	case EXT4_IOC32_GETVERSION:
  		cmd = EXT4_IOC_GETVERSION;

  		break;

  	case EXT4_IOC32_SETVERSION:
  		cmd = EXT4_IOC_SETVERSION;

  		break;

  	case EXT4_IOC32_GROUP_EXTEND:
  		cmd = EXT4_IOC_GROUP_EXTEND;

  		break;

  	case EXT4_IOC32_GETVERSION_OLD:
  		cmd = EXT4_IOC_GETVERSION_OLD;

  		break;

  	case EXT4_IOC32_SETVERSION_OLD:
  		cmd = EXT4_IOC_SETVERSION_OLD;

  		break;

  	case EXT4_IOC32_GETRSVSZ:
  		cmd = EXT4_IOC_GETRSVSZ;

  		break;

  	case EXT4_IOC32_SETRSVSZ:
  		cmd = EXT4_IOC_SETRSVSZ;

  		break;

  	case EXT4_IOC32_GROUP_ADD: {
  		struct compat_ext4_new_group_input __user *uinput;
  		struct ext4_new_group_input input;
  		mm_segment_t old_fs;
  		int err;
  
  		uinput = compat_ptr(arg);
  		err = get_user(input.group, &uinput->group);
  		err |= get_user(input.block_bitmap, &uinput->block_bitmap);
  		err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
  		err |= get_user(input.inode_table, &uinput->inode_table);
  		err |= get_user(input.blocks_count, &uinput->blocks_count);
  		err |= get_user(input.reserved_blocks,
  				&uinput->reserved_blocks);
  		if (err)
  			return -EFAULT;
  		old_fs = get_fs();
  		set_fs(KERNEL_DS);
  		err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
  				 (unsigned long) &input);
  		set_fs(old_fs);
  		return err;
  	}

  	case EXT4_IOC_MOVE_EXT:

  	case EXT4_IOC_RESIZE_FS:

  	case EXT4_IOC_PRECACHE_EXTENTS:

  	case EXT4_IOC_SET_ENCRYPTION_POLICY:
  	case EXT4_IOC_GET_ENCRYPTION_PWSALT:
  	case EXT4_IOC_GET_ENCRYPTION_POLICY:

  		break;

  	default:
  		return -ENOIOCTLCMD;
  	}

  	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));

  }
  #endif