1 files changed, 104 insertions, 1 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 598ae07195b6..05af292eb8ce 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1917,6 +1917,99 @@ static inline bool ata_eh_quiet(struct ata_queued_cmd *qc)
 	return qc->flags & ATA_QCFLAG_QUIET;
 }
 
+static int ata_eh_read_sense_success_non_ncq(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_queued_cmd *qc;
+
+	qc = __ata_qc_from_tag(ap, link->active_tag);
+	if (!qc)
+		return -EIO;
+
+	if (!(qc->flags & ATA_QCFLAG_EH) ||
+	    !(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
+	    qc->err_mask)
+		return -EIO;
+
+	if (!ata_eh_request_sense(qc))
+		return -EIO;
+
+	/*
+	 * If we have sense data, call scsi_check_sense() in order to set the
+	 * correct SCSI ML byte (if any). No point in checking the return value,
+	 * since the command has already completed successfully.
+	 */
+	scsi_check_sense(qc->scsicmd);
+
+	return 0;
+}
+
+static void ata_eh_get_success_sense(struct ata_link *link)
+{
+	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_device *dev = link->device;
+	struct ata_port *ap = link->ap;
+	struct ata_queued_cmd *qc;
+	int tag, ret = 0;
+
+	if (!(ehc->i.dev_action[dev->devno] & ATA_EH_GET_SUCCESS_SENSE))
+		return;
+
+	/* if frozen, we can't do much */
+	if (ata_port_is_frozen(ap)) {
+		ata_dev_warn(dev,
+			"successful sense data available but port frozen\n");
+		goto out;
+	}
+
+	/*
+	 * If the link has sactive set, then we have outstanding NCQ commands
+	 * and have to read the Successful NCQ Commands log to get the sense
+	 * data. Otherwise, we are dealing with a non-NCQ command and use
+	 * request sense ext command to retrieve the sense data.
+	 */
+	if (link->sactive)
+		ret = ata_eh_read_sense_success_ncq_log(link);
+	else
+		ret = ata_eh_read_sense_success_non_ncq(link);
+	if (ret)
+		goto out;
+
+	ata_eh_done(link, dev, ATA_EH_GET_SUCCESS_SENSE);
+	return;
+
+out:
+	/*
+	 * If we failed to get sense data for a successful command that ought to
+	 * have sense data, we cannot simply return BLK_STS_OK to user space.
+	 * This is because we can't know if the sense data that we couldn't get
+	 * was actually "DATA CURRENTLY UNAVAILABLE". Reporting such a command
+	 * as success to user space would result in a silent data corruption.
+	 * Thus, add a bogus ABORTED_COMMAND sense data to such commands, such
+	 * that SCSI will report these commands as BLK_STS_IOERR to user space.
+	 */
+	ata_qc_for_each_raw(ap, qc, tag) {
+		if (!(qc->flags & ATA_QCFLAG_EH) ||
+		    !(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
+		    qc->err_mask ||
+		    ata_dev_phys_link(qc->dev) != link)
+			continue;
+
+		/* We managed to get sense for this success command, skip. */
+		if (qc->flags & ATA_QCFLAG_SENSE_VALID)
+			continue;
+
+		/* This success command did not have any sense data, skip. */
+		if (!(qc->result_tf.status & ATA_SENSE))
+			continue;
+
+		/* This success command had sense data, but we failed to get. */
+		ata_scsi_set_sense(dev, qc->scsicmd, ABORTED_COMMAND, 0, 0);
+		qc->flags |= ATA_QCFLAG_SENSE_VALID;
+	}
+	ata_eh_done(link, dev, ATA_EH_GET_SUCCESS_SENSE);
+}
+
 /**
  *	ata_eh_link_autopsy - analyze error and determine recovery action
  *	@link: host link to perform autopsy on
@@ -1957,6 +2050,14 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 	/* analyze NCQ failure */
 	ata_eh_analyze_ncq_error(link);
 
+	/*
+	 * Check if this was a successful command that simply needs sense data.
+	 * Since the sense data is not part of the completion, we need to fetch
+	 * it using an additional command. Since this can't be done from irq
+	 * context, the sense data for successful commands are fetched by EH.
+	 */
+	ata_eh_get_success_sense(link);
+
 	/* any real error trumps AC_ERR_OTHER */
 	if (ehc->i.err_mask & ~AC_ERR_OTHER)
 		ehc->i.err_mask &= ~AC_ERR_OTHER;
@@ -1966,6 +2067,7 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 	ata_qc_for_each_raw(ap, qc, tag) {
 		if (!(qc->flags & ATA_QCFLAG_EH) ||
 		    qc->flags & ATA_QCFLAG_RETRY ||
+		    qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD ||
 		    ata_dev_phys_link(qc->dev) != link)
 			continue;
 
@@ -3825,7 +3927,8 @@ void ata_eh_finish(struct ata_port *ap)
 			else
 				ata_eh_qc_complete(qc);
 		} else {
-			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
+			if (qc->flags & ATA_QCFLAG_SENSE_VALID ||
+			    qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) {
 				ata_eh_qc_complete(qc);
 			} else {
 				/* feed zero TF to sense generation */