1 files changed, 57 insertions, 23 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 4df73e52a4f..12f6fdfc114 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -262,6 +262,28 @@ sd_show_protection_type(struct device *dev, struct device_attribute *attr,
 }
 
 static ssize_t
+sd_store_protection_type(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+	unsigned int val;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	err = kstrtouint(buf, 10, &val);
+
+	if (err)
+		return err;
+
+	if (val >= 0 && val <= SD_DIF_TYPE3_PROTECTION)
+		sdkp->protection_type = val;
+
+	return count;
+}
+
+static ssize_t
 sd_show_protection_mode(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
@@ -381,7 +403,8 @@ static struct device_attribute sd_disk_attrs[] = {
 	       sd_store_allow_restart),
 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
 	       sd_store_manage_start_stop),
-	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
+	__ATTR(protection_type, S_IRUGO|S_IWUSR, sd_show_protection_type,
+	       sd_store_protection_type),
 	__ATTR(protection_mode, S_IRUGO, sd_show_protection_mode, NULL),
 	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
 	__ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL),
@@ -804,9 +827,8 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 		SCpnt->cmnd[0] = WRITE_6;
 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
 
-		if (blk_integrity_rq(rq) &&
-		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
-			goto out;
+		if (blk_integrity_rq(rq))
+			sd_dif_prepare(rq, block, sdp->sector_size);
 
 	} else if (rq_data_dir(rq) == READ) {
 		SCpnt->cmnd[0] = READ_6;
@@ -1671,34 +1693,42 @@ sd_spinup_disk(struct scsi_disk *sdkp)
 /*
  * Determine whether disk supports Data Integrity Field.
  */
-static void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
+static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
 {
 	struct scsi_device *sdp = sdkp->device;
 	u8 type;
+	int ret = 0;
 
 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
-		return;
+		return ret;
 
 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
 
-	if (type == sdkp->protection_type || !sdkp->first_scan)
-		return;
+	if (type > SD_DIF_TYPE3_PROTECTION)
+		ret = -ENODEV;
+	else if (scsi_host_dif_capable(sdp->host, type))
+		ret = 1;
+
+	if (sdkp->first_scan || type != sdkp->protection_type)
+		switch (ret) {
+		case -ENODEV:
+			sd_printk(KERN_ERR, sdkp, "formatted with unsupported" \
+				  " protection type %u. Disabling disk!\n",
+				  type);
+			break;
+		case 1:
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Enabling DIF Type %u protection\n", type);
+			break;
+		case 0:
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Disabling DIF Type %u protection\n", type);
+			break;
+		}
 
 	sdkp->protection_type = type;
 
-	if (type > SD_DIF_TYPE3_PROTECTION) {
-		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
-			  "protection type %u. Disabling disk!\n", type);
-		sdkp->capacity = 0;
-		return;
-	}
-
-	if (scsi_host_dif_capable(sdp->host, type))
-		sd_printk(KERN_NOTICE, sdkp,
-			  "Enabling DIF Type %u protection\n", type);
-	else
-		sd_printk(KERN_NOTICE, sdkp,
-			  "Disabling DIF Type %u protection\n", type);
+	return ret;
 }
 
 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
@@ -1794,7 +1824,10 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
 	sector_size = get_unaligned_be32(&buffer[8]);
 	lba = get_unaligned_be64(&buffer[0]);
 
-	sd_read_protection_type(sdkp, buffer);
+	if (sd_read_protection_type(sdkp, buffer) < 0) {
+		sdkp->capacity = 0;
+		return -ENODEV;
+	}
 
 	if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
@@ -2632,7 +2665,8 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
 	}
 
 	add_disk(gd);
-	sd_dif_config_host(sdkp);
+	if (sdkp->capacity)
+		sd_dif_config_host(sdkp);
 
 	sd_revalidate_disk(gd);