Пример #1
0
/*
 *  * We need to pick up the new inode size which generic_commit_write gave us
 *   * `file' can be NULL - eg, when called from page_symlink().
 *    *
 *     * ext4 never places buffers on inode->i_mapping->private_list.  metadata
 *      * buffers are managed internally.
 *       */
static int ext4_ordered_write_end(struct file *file,
				  struct address_space *mapping,
				  loff_t pos, unsigned len, unsigned copied,
				  struct page *page, void *fsdata)
{
	handle_t *handle = ext4_journal_current_handle();
	struct inode *inode = mapping->host;
	int ret = 0, ret2;

	trace_ext4_ordered_write_end(inode, pos, len, copied);
	ret = ext4_jbd2_file_inode(handle, inode);

	if (ret == 0) {
		ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
							page, fsdata);
		copied = ret2;
		if (pos + len > inode->i_size && ext4_can_truncate(inode))
			/* if we have allocated more blocks and copied
 * 			 * less. We will have blocks allocated outside
 * 			 			 * inode->i_size. So truncate them
 * 			 			 			 */
			ext4_orphan_add(handle, inode);
		if (ret2 < 0)
			ret = ret2;
#ifndef __PATCH__

#else
	} else {
		unlock_page(page);
		page_cache_release(page);
#endif
	}

	ret2 = ext4_journal_stop(handle);
	if (!ret)
		ret = ret2;

	if (pos + len > inode->i_size) {
		ext4_truncate_failed_write(inode);
		/*
 * 		 * If truncate failed early the inode might still be
 * 		 		 * on the orphan list; we need to make sure the inode
 * 		 		 		 * is removed from the orphan list in that case.
 * 		 		 		 		 */
		if (inode->i_nlink)
			ext4_orphan_del(NULL, inode);
	}


	return ret ? ret : copied;
}
Пример #2
0
static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
					      struct inode *inode,
					      unsigned flags)
{
	int ret, needed_blocks;
	handle_t *handle = NULL;
	int retries = 0, sem_held = 0;
	struct page *page = NULL;
	unsigned from, to;
	struct ext4_iloc iloc;

	if (!ext4_has_inline_data(inode)) {
		/*
		 * clear the flag so that no new write
		 * will trap here again.
		 */
		ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
		return 0;
	}

	needed_blocks = ext4_writepage_trans_blocks(inode);

	ret = ext4_get_inode_loc(inode, &iloc);
	if (ret)
		return ret;

retry:
	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		handle = NULL;
		goto out;
	}

	/* We cannot recurse into the filesystem as the transaction is already
	 * started */
	flags |= AOP_FLAG_NOFS;

	page = grab_cache_page_write_begin(mapping, 0, flags);
	if (!page) {
		ret = -ENOMEM;
		goto out;
	}

	down_write(&EXT4_I(inode)->xattr_sem);
	sem_held = 1;
	/* If some one has already done this for us, just exit. */
	if (!ext4_has_inline_data(inode)) {
		ret = 0;
		goto out;
	}

	from = 0;
	to = ext4_get_inline_size(inode);
	if (!PageUptodate(page)) {
		ret = ext4_read_inline_page(inode, page);
		if (ret < 0)
			goto out;
	}

	ret = ext4_destroy_inline_data_nolock(handle, inode);
	if (ret)
		goto out;

	if (ext4_should_dioread_nolock(inode)) {
		ret = __block_write_begin(page, from, to,
					  ext4_get_block_unwritten);
	} else
		ret = __block_write_begin(page, from, to, ext4_get_block);

	if (!ret && ext4_should_journal_data(inode)) {
		ret = ext4_walk_page_buffers(handle, page_buffers(page),
					     from, to, NULL,
					     do_journal_get_write_access);
	}

	if (ret) {
		unlock_page(page);
		page_cache_release(page);
		page = NULL;
		ext4_orphan_add(handle, inode);
		up_write(&EXT4_I(inode)->xattr_sem);
		sem_held = 0;
		ext4_journal_stop(handle);
		handle = NULL;
		ext4_truncate_failed_write(inode);
		/*
		 * If truncate failed early the inode might
		 * still be on the orphan list; we need to
		 * make sure the inode is removed from the
		 * orphan list in that case.
		 */
		if (inode->i_nlink)
			ext4_orphan_del(NULL, inode);
	}

	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry;

	if (page)
		block_commit_write(page, from, to);
out:
	if (page) {
		unlock_page(page);
		page_cache_release(page);
	}
	if (sem_held)
		up_write(&EXT4_I(inode)->xattr_sem);
	if (handle)
		ext4_journal_stop(handle);
	brelse(iloc.bh);
	return ret;
}
Пример #3
0
void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
{
	handle_t *handle;
	int inline_size, value_len, needed_blocks;
	size_t i_size;
	void *value = NULL;
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = -ENODATA, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM,
		.name = EXT4_XATTR_SYSTEM_DATA,
	};


	needed_blocks = ext4_writepage_trans_blocks(inode);
	handle = ext4_journal_start(inode, EXT4_HT_INODE, needed_blocks);
	if (IS_ERR(handle))
		return;

	down_write(&EXT4_I(inode)->xattr_sem);
	if (!ext4_has_inline_data(inode)) {
		*has_inline = 0;
		ext4_journal_stop(handle);
		return;
	}

	if (ext4_orphan_add(handle, inode))
		goto out;

	if (ext4_get_inode_loc(inode, &is.iloc))
		goto out;

	down_write(&EXT4_I(inode)->i_data_sem);
	i_size = inode->i_size;
	inline_size = ext4_get_inline_size(inode);
	EXT4_I(inode)->i_disksize = i_size;

	if (i_size < inline_size) {
		/* Clear the content in the xattr space. */
		if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) {
			if (ext4_xattr_ibody_find(inode, &i, &is))
				goto out_error;

			BUG_ON(is.s.not_found);

			value_len = le32_to_cpu(is.s.here->e_value_size);
			value = kmalloc(value_len, GFP_NOFS);
			if (!value)
				goto out_error;

			if (ext4_xattr_ibody_get(inode, i.name_index, i.name,
						value, value_len))
				goto out_error;

			i.value = value;
			i.value_len = i_size > EXT4_MIN_INLINE_DATA_SIZE ?
					i_size - EXT4_MIN_INLINE_DATA_SIZE : 0;
			if (ext4_xattr_ibody_inline_set(handle, inode, &i, &is))
				goto out_error;
		}

		/* Clear the content within i_blocks. */
		if (i_size < EXT4_MIN_INLINE_DATA_SIZE) {
			void *p = (void *) ext4_raw_inode(&is.iloc)->i_block;
			memset(p + i_size, 0,
			       EXT4_MIN_INLINE_DATA_SIZE - i_size);
		}

		EXT4_I(inode)->i_inline_size = i_size <
					EXT4_MIN_INLINE_DATA_SIZE ?
					EXT4_MIN_INLINE_DATA_SIZE : i_size;
	}

out_error:
	up_write(&EXT4_I(inode)->i_data_sem);
out:
	brelse(is.iloc.bh);
	up_write(&EXT4_I(inode)->xattr_sem);
	kfree(value);
	if (inode->i_nlink)
		ext4_orphan_del(handle, inode);

	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
	ext4_mark_inode_dirty(handle, inode);
	if (IS_SYNC(inode))
		ext4_handle_sync(handle);

	ext4_journal_stop(handle);
	return;
}
Пример #4
0
int ext4_ext_migrate(struct inode *inode)
{
	handle_t *handle;
	int retval = 0, i;
	__le32 *i_data;
	struct ext4_inode_info *ei;
	struct inode *tmp_inode = NULL;
	struct migrate_struct lb;
	unsigned long max_entries;
	__u32 goal;
	uid_t owner[2];

	/*
	 * If the filesystem does not support extents, or the inode
	 * already is extent-based, error out.
	 */
	if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
				       EXT4_FEATURE_INCOMPAT_EXTENTS) ||
	    (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
		return -EINVAL;

	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
		/*
		 * don't migrate fast symlink
		 */
		return retval;

	/*
	 * Worst case we can touch the allocation bitmaps, a bgd
	 * block, and a block to link in the orphan list.  We do need
	 * need to worry about credits for modifying the quota inode.
	 */
	handle = ext4_journal_start(inode, EXT4_HT_MIGRATE,
		4 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));

	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		return retval;
	}
	goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
		EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
	owner[0] = i_uid_read(inode);
	owner[1] = i_gid_read(inode);
	tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
				   S_IFREG, NULL, goal, owner);
	if (IS_ERR(tmp_inode)) {
		retval = PTR_ERR(tmp_inode);
		ext4_journal_stop(handle);
		return retval;
	}
	i_size_write(tmp_inode, i_size_read(inode));
	/*
	 * Set the i_nlink to zero so it will be deleted later
	 * when we drop inode reference.
	 */
	clear_nlink(tmp_inode);

	ext4_ext_tree_init(handle, tmp_inode);
	ext4_orphan_add(handle, tmp_inode);
	ext4_journal_stop(handle);

	/*
	 * start with one credit accounted for
	 * superblock modification.
	 *
	 * For the tmp_inode we already have committed the
	 * trascation that created the inode. Later as and
	 * when we add extents we extent the journal
	 */
	/*
	 * Even though we take i_mutex we can still cause block
	 * allocation via mmap write to holes. If we have allocated
	 * new blocks we fail migrate.  New block allocation will
	 * clear EXT4_STATE_EXT_MIGRATE flag.  The flag is updated
	 * with i_data_sem held to prevent racing with block
	 * allocation.
	 */
	down_read((&EXT4_I(inode)->i_data_sem));
	ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
	up_read((&EXT4_I(inode)->i_data_sem));

	handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
	if (IS_ERR(handle)) {
		/*
		 * It is impossible to update on-disk structures without
		 * a handle, so just rollback in-core changes and live other
		 * work to orphan_list_cleanup()
		 */
		ext4_orphan_del(NULL, tmp_inode);
		retval = PTR_ERR(handle);
		goto out;
	}

	ei = EXT4_I(inode);
	i_data = ei->i_data;
	memset(&lb, 0, sizeof(lb));

	/* 32 bit block address 4 bytes */
	max_entries = inode->i_sb->s_blocksize >> 2;
	for (i = 0; i < EXT4_NDIR_BLOCKS; i++) {
		if (i_data[i]) {
			retval = update_extent_range(handle, tmp_inode,
						le32_to_cpu(i_data[i]), &lb);
			if (retval)
				goto err_out;
		} else
			lb.curr_block++;
	}
	if (i_data[EXT4_IND_BLOCK]) {
		retval = update_ind_extent_range(handle, tmp_inode,
				le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb);
			if (retval)
				goto err_out;
	} else
		lb.curr_block += max_entries;
	if (i_data[EXT4_DIND_BLOCK]) {
		retval = update_dind_extent_range(handle, tmp_inode,
				le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb);
			if (retval)
				goto err_out;
	} else
		lb.curr_block += max_entries * max_entries;
	if (i_data[EXT4_TIND_BLOCK]) {
		retval = update_tind_extent_range(handle, tmp_inode,
				le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb);
			if (retval)
				goto err_out;
	}
	/*
	 * Build the last extent
	 */
	retval = finish_range(handle, tmp_inode, &lb);
err_out:
	if (retval)
		/*
		 * Failure case delete the extent information with the
		 * tmp_inode
		 */
		free_ext_block(handle, tmp_inode);
	else {
		retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
		if (retval)
			/*
			 * if we fail to swap inode data free the extent
			 * details of the tmp inode
			 */
			free_ext_block(handle, tmp_inode);
	}

	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
	if (ext4_journal_extend(handle, 1) != 0)
		ext4_journal_restart(handle, 1);

	/*
	 * Mark the tmp_inode as of size zero
	 */
	i_size_write(tmp_inode, 0);

	/*
	 * set the  i_blocks count to zero
	 * so that the ext4_delete_inode does the
	 * right job
	 *
	 * We don't need to take the i_lock because
	 * the inode is not visible to user space.
	 */
	tmp_inode->i_blocks = 0;

	/* Reset the extent details */
	ext4_ext_tree_init(handle, tmp_inode);
	ext4_journal_stop(handle);
out:
	unlock_new_inode(tmp_inode);
	iput(tmp_inode);

	return retval;
}
Пример #5
0
int ext4_ext_migrate(struct inode *inode)
{
	handle_t *handle;
	int retval = 0, i;
	__le32 *i_data;
	ext4_lblk_t blk_count = 0;
	struct ext4_inode_info *ei;
	struct inode *tmp_inode = NULL;
	struct list_blocks_struct lb;
	unsigned long max_entries;
	__u32 goal;

	/*
	 * If the filesystem does not support extents, or the inode
	 * already is extent-based, error out.
	 */
	if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
				       EXT4_FEATURE_INCOMPAT_EXTENTS) ||
	    (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
		return -EINVAL;

	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
		/*
		 * don't migrate fast symlink
		 */
		return retval;

	handle = ext4_journal_start(inode,
					EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
					EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
					+ 1);
	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		return retval;
	}
	goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
		EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
	tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
				   S_IFREG, 0, goal);
	if (IS_ERR(tmp_inode)) {
		retval = -ENOMEM;
		ext4_journal_stop(handle);
		return retval;
	}
	i_size_write(tmp_inode, i_size_read(inode));
	/*
	 * We don't want the inode to be reclaimed
	 * if we got interrupted in between. We have
	 * this tmp inode carrying reference to the
	 * data blocks of the original file. We set
	 * the i_nlink to zero at the last stage after
	 * switching the original file to extent format
	 */
	tmp_inode->i_nlink = 1;

	ext4_ext_tree_init(handle, tmp_inode);
	ext4_orphan_add(handle, tmp_inode);
	ext4_journal_stop(handle);

	/*
	 * start with one credit accounted for
	 * superblock modification.
	 *
	 * For the tmp_inode we already have commited the
	 * trascation that created the inode. Later as and
	 * when we add extents we extent the journal
	 */
	/*
	 * Even though we take i_mutex we can still cause block
	 * allocation via mmap write to holes. If we have allocated
	 * new blocks we fail migrate.  New block allocation will
	 * clear EXT4_STATE_EXT_MIGRATE flag.  The flag is updated
	 * with i_data_sem held to prevent racing with block
	 * allocation.
	 */
	down_read((&EXT4_I(inode)->i_data_sem));
	EXT4_I(inode)->i_state |= EXT4_STATE_EXT_MIGRATE;
	up_read((&EXT4_I(inode)->i_data_sem));

	handle = ext4_journal_start(inode, 1);

	ei = EXT4_I(inode);
	i_data = ei->i_data;
	memset(&lb, 0, sizeof(lb));

	/* 32 bit block address 4 bytes */
	max_entries = inode->i_sb->s_blocksize >> 2;
	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
		if (i_data[i]) {
			retval = update_extent_range(handle, tmp_inode,
						le32_to_cpu(i_data[i]),
						blk_count, &lb);
			if (retval)
				goto err_out;
		}
	}
	if (i_data[EXT4_IND_BLOCK]) {
		retval = update_ind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_IND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	} else
		blk_count +=  max_entries;
	if (i_data[EXT4_DIND_BLOCK]) {
		retval = update_dind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	} else
		blk_count += max_entries * max_entries;
	if (i_data[EXT4_TIND_BLOCK]) {
		retval = update_tind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	}
	/*
	 * Build the last extent
	 */
	retval = finish_range(handle, tmp_inode, &lb);
err_out:
	if (retval)
		/*
		 * Failure case delete the extent information with the
		 * tmp_inode
		 */
		free_ext_block(handle, tmp_inode);
	else {
		retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
		if (retval)
			/*
			 * if we fail to swap inode data free the extent
			 * details of the tmp inode
			 */
			free_ext_block(handle, tmp_inode);
	}

	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
	if (ext4_journal_extend(handle, 1) != 0)
		ext4_journal_restart(handle, 1);

	/*
	 * Mark the tmp_inode as of size zero
	 */
	i_size_write(tmp_inode, 0);

	/*
	 * set the  i_blocks count to zero
	 * so that the ext4_delete_inode does the
	 * right job
	 *
	 * We don't need to take the i_lock because
	 * the inode is not visible to user space.
	 */
	tmp_inode->i_blocks = 0;

	/* Reset the extent details */
	ext4_ext_tree_init(handle, tmp_inode);

	/*
	 * Set the i_nlink to zero so that
	 * generic_drop_inode really deletes the
	 * inode
	 */
	tmp_inode->i_nlink = 0;

	ext4_journal_stop(handle);
	unlock_new_inode(tmp_inode);
	iput(tmp_inode);

	return retval;
}
Пример #6
0
void ext4_inline_data_truncate(struct inode *inode)
{
	handle_t *handle;
	int inline_size = ext4_get_inline_size(inode);
	size_t isize = i_size_read(inode);
	int needed_blocks, value_len;
	void *value = NULL;
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = -ENODATA, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM_DATA,
		.name = EXT4_XATTR_SYSTEM_DATA_NAME,
	};

	needed_blocks = ext4_writepage_trans_blocks(inode);
	handle = ext4_journal_start(inode, needed_blocks);
	if (IS_ERR(handle))
		return;

	if (ext4_orphan_add(handle, inode))
		goto out;

	EXT4_I(inode)->i_disksize = inode->i_size;

	if (isize < ext4_get_max_inline_size(inode)) {
		if (ext4_get_inode_loc(inode, &is.iloc))
			goto out;

		if (isize < EXT4_MIN_INLINE_DATA_SIZE)
			memset(ext4_raw_inode(&is.iloc)->i_block + isize, 0,
					EXT4_MIN_INLINE_DATA_SIZE - isize);
		if (inline_size > EXT4_MIN_INLINE_DATA_SIZE &&
				isize < inline_size) {
			if (ext4_xattr_ibody_find(inode, &i, &is))
				goto out_bh;

			BUG_ON(is.s.not_found);

			value_len = le32_to_cpu(is.s.here->e_value_size);
			value = kmalloc(value_len, GFP_NOFS);

			if (ext4_xattr_ibody_get(inode, i.name_index, i.name,
						value, value_len))
				goto out_bh;

			i.value = value;
			i.value_len = isize - EXT4_MIN_INLINE_DATA_SIZE;
			if (ext4_xattr_ibody_inline_set(handle, inode, &i, &is))
				goto out_bh;
		}
		if (isize < inline_size)
			EXT4_I(inode)->i_inline_size = isize <
				EXT4_MIN_INLINE_DATA_SIZE ?
				EXT4_MIN_INLINE_DATA_SIZE : isize;
out_bh:
		if (value)
			kfree(value);
		brelse(is.iloc.bh);
	} else
		ext4_convert_inline_data_to_extent(inode->i_mapping, inode, 0);

out:
	if (inode->i_nlink)
		ext4_orphan_del(handle, inode);

	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
	ext4_mark_inode_dirty(handle, inode);
	if (IS_SYNC(inode))
		ext4_handle_sync(handle);

	ext4_journal_stop(handle);
}
Пример #7
0
int ext4_ext_migrate(struct inode *inode, struct file *filp,
				unsigned int cmd, unsigned long arg)
{
	handle_t *handle;
	int retval = 0, i;
	__le32 *i_data;
	ext4_lblk_t blk_count = 0;
	struct ext4_inode_info *ei;
	struct inode *tmp_inode = NULL;
	struct list_blocks_struct lb;
	unsigned long max_entries;

	if (!test_opt(inode->i_sb, EXTENTS))
		/*
		 * if mounted with noextents we don't allow the migrate
		 */
		return -EINVAL;

	if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
		return -EINVAL;

	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
		/*
		 * don't migrate fast symlink
		 */
		return retval;

	handle = ext4_journal_start(inode,
					EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
					2 * EXT4_QUOTA_INIT_BLOCKS(inode->i_sb)
					+ 1);
	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		goto err_out;
	}
	tmp_inode = ext4_new_inode(handle,
				inode->i_sb->s_root->d_inode,
				S_IFREG);
	if (IS_ERR(tmp_inode)) {
		retval = -ENOMEM;
		ext4_journal_stop(handle);
		tmp_inode = NULL;
		goto err_out;
	}
	i_size_write(tmp_inode, i_size_read(inode));
	/*
	 * We don't want the inode to be reclaimed
	 * if we got interrupted in between. We have
	 * this tmp inode carrying reference to the
	 * data blocks of the original file. We set
	 * the i_nlink to zero at the last stage after
	 * switching the original file to extent format
	 */
	tmp_inode->i_nlink = 1;

	ext4_ext_tree_init(handle, tmp_inode);
	ext4_orphan_add(handle, tmp_inode);
	ext4_journal_stop(handle);

	/*
	 * start with one credit accounted for
	 * superblock modification.
	 *
	 * For the tmp_inode we already have commited the
	 * trascation that created the inode. Later as and
	 * when we add extents we extent the journal
	 */
	/*
	 * 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.
	 */
	mutex_lock(&(inode->i_mutex));
	handle = ext4_journal_start(inode, 1);

	ei = EXT4_I(inode);
	i_data = ei->i_data;
	memset(&lb, 0, sizeof(lb));

	/* 32 bit block address 4 bytes */
	max_entries = inode->i_sb->s_blocksize >> 2;
	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
		if (i_data[i]) {
			retval = update_extent_range(handle, tmp_inode,
						le32_to_cpu(i_data[i]),
						blk_count, &lb);
			if (retval)
				goto err_out;
		}
	}
	if (i_data[EXT4_IND_BLOCK]) {
		retval = update_ind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_IND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	} else
		blk_count +=  max_entries;
	if (i_data[EXT4_DIND_BLOCK]) {
		retval = update_dind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	} else
		blk_count += max_entries * max_entries;
	if (i_data[EXT4_TIND_BLOCK]) {
		retval = update_tind_extent_range(handle, tmp_inode,
					le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
					&blk_count, &lb);
			if (retval)
				goto err_out;
	}
	/*
	 * Build the last extent
	 */
	retval = finish_range(handle, tmp_inode, &lb);
err_out:
	if (retval)
		/*
		 * Failure case delete the extent information with the
		 * tmp_inode
		 */
		free_ext_block(handle, tmp_inode);
	else
		retval = ext4_ext_swap_inode_data(handle, inode,
							tmp_inode);

	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
	if (ext4_journal_extend(handle, 1) != 0)
		ext4_journal_restart(handle, 1);

	/*
	 * Mark the tmp_inode as of size zero
	 */
	i_size_write(tmp_inode, 0);

	/*
	 * set the  i_blocks count to zero
	 * so that the ext4_delete_inode does the
	 * right job
	 *
	 * We don't need to take the i_lock because
	 * the inode is not visible to user space.
	 */
	tmp_inode->i_blocks = 0;

	/* Reset the extent details */
	ext4_ext_tree_init(handle, tmp_inode);

	/*
	 * Set the i_nlink to zero so that
	 * generic_drop_inode really deletes the
	 * inode
	 */
	tmp_inode->i_nlink = 0;

	ext4_journal_stop(handle);
	mutex_unlock(&(inode->i_mutex));

	if (tmp_inode)
		iput(tmp_inode);

	return retval;
}