On Sep 29, 2021, at 4:17 AM, Damien Le Moal [off-list ref] wrote:

Remove unnecessary gotos in scsi_get_vpd_page() to improve the code
readability and use memchr() instead of an open coded search loop.
Also update the outdated kernel doc comment for this function.

Signed-off-by: Damien Le Moal <redacted>
---
drivers/scsi/scsi.c | 31 ++++++++++++++-----------------
1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index b241f9e3885c..6be68b3427a0 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c

@@ -339,47 +339,44 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
 *
 * SCSI devices may optionally supply Vital Product Data.  Each 'page'
 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
- * If the device supports this VPD page, this routine returns a pointer
- * to a buffer containing the data from that page.  The caller is
- * responsible for calling kfree() on this pointer when it is no longer
- * needed.  If we cannot retrieve the VPD page this routine returns %NULL.
+ * If the device supports this VPD page, this routine fills @buf
+ * with the data from that page and return 0. If the VPD page is not
+ * supported or its content cannot be retrieved, -EINVAL is returned.
 */

int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
		      int buf_len)
{
-	int i, result;
+	int result, len;

	if (sdev->skip_vpd_pages)
-		goto fail;
+		return -EINVAL;

	/* Ask for all the pages supported by this device */
	result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
	if (result < 4)
-		goto fail;
+		return -EINVAL;

	/* If the user actually wanted this page, we can skip the rest */
	if (page == 0)
		return 0;

-	for (i = 4; i < min(result, buf_len); i++)
-		if (buf[i] == page)
-			goto found;
+	len = min(result, buf_len);
+	if (len > 4 && memchr(&buf[4], page, len - 4))
+		goto found;

-	if (i < result && i >= buf_len)
-		/* ran off the end of the buffer, give us benefit of doubt */
+	/* If we ran off the end of the buffer, give us benefit of doubt */
+	if (result > buf_len)
		goto found;
+
	/* The device claims it doesn't support the requested page */
-	goto fail;
+	return -EINVAL;

 found:
	result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
	if (result < 0)
-		goto fail;
+		return -EINVAL;

	return 0;
-
- fail:
-	return -EINVAL;
}
EXPORT_SYMBOL_GPL(scsi_get_vpd_page);

-- 
2.31.1