[PATCH] libata-eh set tf flags in NCQ EH result_tf

[Mark Lord <liml@rtr.ca>]

Fix mis-reporting of NCQ errors by ensuring that result_tf->flags
is properly initialized in libata-eh.  This allows ata_gen_ata_sense()
to report the failed block number correctly to SCSI after a media error
during NCQ.

This patch may also be a candidate for backporting to earlier kernels.
Without this fix, SCSI will fail I/O on the entire request rather
than just the bad sector.  That can be bad for a request that was
merged from many independent read reads from different tasks.

Signed-off-by: Mark Lord <mlord@pobox.com> 
---

This is an alternative version of the original patch
which safely copied the outgoing tf.flags to result_tf.flags.
Both work.  Pick one.

--- upstream/drivers/ata/libata-eh.c	2008-04-18 09:31:15.000000000 -0400
+++ linux/drivers/ata/libata-eh.c	2008-04-23 16:25:38.000000000 -0400
@@ -1402,6 +1402,7 @@
 	/* we've got the perpetrator, condemn it */
 	qc = __ata_qc_from_tag(ap, tag);
 	memcpy(&qc->result_tf, &tf, sizeof(tf));
+	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
 	ehc->i.err_mask &= ~AC_ERR_DEV;
 }