static int ext4_releasepage(struct page *page, gfp_t wait)
{
	journal_t *journal = EXT4_JOURNAL(page->mapping->host);

	trace_ext4_releasepage(page);

	/* Page has dirty journalled data -> cannot release */
	if (PageChecked(page))
		return 0;
	if (journal)
		return jbd2_journal_try_to_free_buffers(journal, page);
	else
		return try_to_free_buffers(page);
}
static int ext4_releasepage(struct page *page, gfp_t wait)
{
	journal_t *journal = EXT4_JOURNAL(page->mapping->host);

	trace_ext4_releasepage(page);

	 
	if (PageChecked(page))
		return 0;
	if (journal)
		return jbd2_journal_try_to_free_buffers(journal, page);
	else
		return try_to_free_buffers(page);
}