storvsc: fix a bug in storvsc limits

Commit 4cd83ecdac20d30725b4f96e5d7814a1e290bc7e changed the limits to
reflect the values on the host. It turns out that WS2008R2 cannot
correctly handle these new limits. Fix this bug by setting the limits
based on the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index ae8293a..caa9f0e 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1678,6 +1678,9 @@
 	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
 	int target = 0;
 	struct storvsc_device *stor_device;
+	int max_luns_per_target;
+	int max_targets;
+	int max_channels;
 
 	/*
 	 * Based on the windows host we are running on,
@@ -1691,12 +1694,18 @@
 		vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 		vmstor_current_major = VMSTOR_WIN7_MAJOR;
 		vmstor_current_minor = VMSTOR_WIN7_MINOR;
+		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
+		max_targets = STORVSC_IDE_MAX_TARGETS;
+		max_channels = STORVSC_IDE_MAX_CHANNELS;
 		break;
 	default:
 		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
 		vmscsi_size_delta = 0;
 		vmstor_current_major = VMSTOR_WIN8_MAJOR;
 		vmstor_current_minor = VMSTOR_WIN8_MINOR;
+		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
+		max_targets = STORVSC_MAX_TARGETS;
+		max_channels = STORVSC_MAX_CHANNELS;
 		break;
 	}
 
@@ -1744,9 +1753,9 @@
 		break;
 
 	case SCSI_GUID:
-		host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
-		host->max_id = STORVSC_MAX_TARGETS;
-		host->max_channel = STORVSC_MAX_CHANNELS - 1;
+		host->max_lun = max_luns_per_target;
+		host->max_id = max_targets;
+		host->max_channel = max_channels - 1;
 		break;
 
 	default: