xfs: also truncate holes covered by COW blocks

	wpc->fork = XFS_DATA_FORK;

	/* landed in a hole or beyond EOF? */

	if (imap.br_startoff > offset_fsb) {

		/* landed in a hole or beyond EOF */

		imap.br_blockcount = imap.br_startoff - offset_fsb;

		imap.br_startoff = offset_fsb;

		imap.br_startblock = HOLESTARTBLOCK;

		imap.br_state = XFS_EXT_NORM;

	} else {

	}

	/*

		 * Truncate to the next COW extent if there is one.  This is the

		 * only opportunity to do this because we can skip COW fork

		 * lookups for the subsequent blocks in the mapping; however,

		 * the requirement to treat the COW range separately remains.

	 * Truncate to the next COW extent if there is one.  This is the only

	 * opportunity to do this because we can skip COW fork lookups for the

	 * subsequent blocks in the mapping; however, the requirement to treat

	 * the COW range separately remains.

	 */

	if (cow_fsb != NULLFILEOFF &&

	    cow_fsb < imap.br_startoff + imap.br_blockcount)

		imap.br_blockcount = cow_fsb - imap.br_startoff;

	/* got a delalloc extent? */

		if (isnullstartblock(imap.br_startblock))

	if (imap.br_startblock != HOLESTARTBLOCK &&

	    isnullstartblock(imap.br_startblock))

		goto allocate_blocks;

	}

	wpc->imap = imap;

	trace_xfs_map_blocks_found(ip, offset, count, wpc->fork, &imap);