[PATCH 1/2] Introduce scsi_get_vpd_buf()

[Bart Van Assche <bart.vanassche@wdc.com>]

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Shane M Seymour <shane.seymour@hpe.com>
---
 drivers/scsi/scsi.c | 96 +++++++++++++++++++++++++----------------------------
 1 file changed, 45 insertions(+), 51 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 3d38c6d463b8..775f609f89e2 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -411,6 +411,41 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
 }
 EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
 
+/**
+ * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device
+ * @sdev: The device to ask
+ * @page: Which Vital Product Data to return
+ * @len: Upon success, the VPD length will be stored in *@len.
+ *
+ * Returns %NULL upon failure.
+ */
+static unsigned char *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page,
+				       int *len)
+{
+	unsigned char *vpd_buf;
+	int vpd_len = SCSI_VPD_PG_LEN, result;
+
+retry_pg:
+	vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+	if (!vpd_buf)
+		return NULL;
+
+	result = scsi_vpd_inquiry(sdev, vpd_buf, page, vpd_len);
+	if (result < 0) {
+		kfree(vpd_buf);
+		return NULL;
+	}
+	if (result > vpd_len) {
+		vpd_len = result;
+		kfree(vpd_buf);
+		goto retry_pg;
+	}
+
+	*len = result;
+
+	return vpd_buf;
+}
+
 /**
  * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
  * @sdev: The device to ask
@@ -422,8 +457,8 @@ EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
  */
 void scsi_attach_vpd(struct scsi_device *sdev)
 {
-	int result, i;
-	int vpd_len = SCSI_VPD_PG_LEN;
+	int i;
+	int vpd_len;
 	int pg80_supported = 0;
 	int pg83_supported = 0;
 	unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL;
@@ -431,51 +466,25 @@ void scsi_attach_vpd(struct scsi_device *sdev)
 	if (!scsi_device_supports_vpd(sdev))
 		return;
 
-retry_pg0:
-	vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+	/* Ask for all the pages supported by this device */
+	vpd_buf = scsi_get_vpd_buf(sdev, 0, &vpd_len);
 	if (!vpd_buf)
 		return;
 
-	/* Ask for all the pages supported by this device */
-	result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
-	if (result < 0) {
-		kfree(vpd_buf);
-		return;
-	}
-	if (result > vpd_len) {
-		vpd_len = result;
-		kfree(vpd_buf);
-		goto retry_pg0;
-	}
-
-	for (i = 4; i < result; i++) {
+	for (i = 4; i < vpd_len; i++) {
 		if (vpd_buf[i] == 0x80)
 			pg80_supported = 1;
 		if (vpd_buf[i] == 0x83)
 			pg83_supported = 1;
 	}
 	kfree(vpd_buf);
-	vpd_len = SCSI_VPD_PG_LEN;
 
 	if (pg80_supported) {
-retry_pg80:
-		vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
-		if (!vpd_buf)
-			return;
-
-		result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
-		if (result < 0) {
-			kfree(vpd_buf);
-			return;
-		}
-		if (result > vpd_len) {
-			vpd_len = result;
-			kfree(vpd_buf);
-			goto retry_pg80;
-		}
+		vpd_buf = scsi_get_vpd_buf(sdev, 0x80, &vpd_len);
+
 		mutex_lock(&sdev->inquiry_mutex);
 		orig_vpd_buf = sdev->vpd_pg80;
-		sdev->vpd_pg80_len = result;
+		sdev->vpd_pg80_len = vpd_len;
 		rcu_assign_pointer(sdev->vpd_pg80, vpd_buf);
 		mutex_unlock(&sdev->inquiry_mutex);
 		synchronize_rcu();
@@ -483,28 +492,13 @@ void scsi_attach_vpd(struct scsi_device *sdev)
 			kfree(orig_vpd_buf);
 			orig_vpd_buf = NULL;
 		}
-		vpd_len = SCSI_VPD_PG_LEN;
 	}
 
 	if (pg83_supported) {
-retry_pg83:
-		vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
-		if (!vpd_buf)
-			return;
-
-		result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
-		if (result < 0) {
-			kfree(vpd_buf);
-			return;
-		}
-		if (result > vpd_len) {
-			vpd_len = result;
-			kfree(vpd_buf);
-			goto retry_pg83;
-		}
+		vpd_buf = scsi_get_vpd_buf(sdev, 0x83, &vpd_len);
 		mutex_lock(&sdev->inquiry_mutex);
 		orig_vpd_buf = sdev->vpd_pg83;
-		sdev->vpd_pg83_len = result;
+		sdev->vpd_pg83_len = vpd_len;
 		rcu_assign_pointer(sdev->vpd_pg83, vpd_buf);
 		mutex_unlock(&sdev->inquiry_mutex);
 		synchronize_rcu();
-- 
2.14.1