1 files changed, 94 insertions, 0 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index bba2ae5df1c2..0ea97c942ced 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -110,6 +110,13 @@ static const unsigned long ata_eh_identify_timeouts[] = {
 	ULONG_MAX,
 };
 
+static const unsigned long ata_eh_flush_timeouts[] = {
+	15000,	/* be generous with flush */
+	15000,  /* ditto */
+	30000,	/* and even more generous */
+	ULONG_MAX,
+};
+
 static const unsigned long ata_eh_other_timeouts[] = {
 	 5000,	/* same rationale as identify timeout */
 	10000,	/* ditto */
@@ -147,6 +154,8 @@ ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
 	  .timeouts = ata_eh_other_timeouts, },
 	{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
 	  .timeouts = ata_eh_other_timeouts, },
+	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
+	  .timeouts = ata_eh_flush_timeouts },
 };
 #undef CMDS
 
@@ -3112,6 +3121,82 @@ static int atapi_eh_clear_ua(struct ata_device *dev)
 	return 0;
 }
 
+/**
+ *	ata_eh_maybe_retry_flush - Retry FLUSH if necessary
+ *	@dev: ATA device which may need FLUSH retry
+ *
+ *	If @dev failed FLUSH, it needs to be reported upper layer
+ *	immediately as it means that @dev failed to remap and already
+ *	lost at least a sector and further FLUSH retrials won't make
+ *	any difference to the lost sector.  However, if FLUSH failed
+ *	for other reasons, for example transmission error, FLUSH needs
+ *	to be retried.
+ *
+ *	This function determines whether FLUSH failure retry is
+ *	necessary and performs it if so.
+ *
+ *	RETURNS:
+ *	0 if EH can continue, -errno if EH needs to be repeated.
+ */
+static int ata_eh_maybe_retry_flush(struct ata_device *dev)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	struct ata_queued_cmd *qc;
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+	int rc = 0;
+
+	/* did flush fail for this device? */
+	if (!ata_tag_valid(link->active_tag))
+		return 0;
+
+	qc = __ata_qc_from_tag(ap, link->active_tag);
+	if (qc->dev != dev || (qc->tf.command != ATA_CMD_FLUSH_EXT &&
+			       qc->tf.command != ATA_CMD_FLUSH))
+		return 0;
+
+	/* if the device failed it, it should be reported to upper layers */
+	if (qc->err_mask & AC_ERR_DEV)
+		return 0;
+
+	/* flush failed for some other reason, give it another shot */
+	ata_tf_init(dev, &tf);
+
+	tf.command = qc->tf.command;
+	tf.flags |= ATA_TFLAG_DEVICE;
+	tf.protocol = ATA_PROT_NODATA;
+
+	ata_dev_printk(dev, KERN_WARNING, "retrying FLUSH 0x%x Emask 0x%x\n",
+		       tf.command, qc->err_mask);
+
+	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
+	if (!err_mask) {
+		/*
+		 * FLUSH is complete but there's no way to
+		 * successfully complete a failed command from EH.
+		 * Making sure retry is allowed at least once and
+		 * retrying it should do the trick - whatever was in
+		 * the cache is already on the platter and this won't
+		 * cause infinite loop.
+		 */
+		qc->scsicmd->allowed = max(qc->scsicmd->allowed, 1);
+	} else {
+		ata_dev_printk(dev, KERN_WARNING, "FLUSH failed Emask 0x%x\n",
+			       err_mask);
+		rc = -EIO;
+
+		/* if device failed it, report it to upper layers */
+		if (err_mask & AC_ERR_DEV) {
+			qc->err_mask |= AC_ERR_DEV;
+			qc->result_tf = tf;
+			if (!(ap->pflags & ATA_PFLAG_FROZEN))
+				rc = 0;
+		}
+	}
+	return rc;
+}
+
 static int ata_link_nr_enabled(struct ata_link *link)
 {
 	struct ata_device *dev;
@@ -3455,6 +3540,15 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 			}
 		}
 
+		/* retry flush if necessary */
+		ata_for_each_dev(dev, link, ALL) {
+			if (dev->class != ATA_DEV_ATA)
+				continue;
+			rc = ata_eh_maybe_retry_flush(dev);
+			if (rc)
+				goto dev_fail;
+		}
+
 		/* configure link power saving */
 		if (ehc->i.action & ATA_EH_LPM)
 			ata_for_each_dev(dev, link, ALL)