FAILED: patch "[PATCH] sd: Fix rw_max for devices that report an optimal xfer size" failed to apply to 4.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 6b7e9cde49691e04314342b7dce90c67ad567fcc Mon Sep 17 00:00:00 2001
From: "Martin K. Petersen" <martin.petersen@oracle.com>
Date: Thu, 12 May 2016 22:17:34 -0400
Subject: [PATCH] sd: Fix rw_max for devices that report an optimal xfer size

For historic reasons, io_opt is in bytes and max_sectors in block layer
sectors. This interface inconsistency is error prone and should be
fixed. But for 4.4--4.7 let's make the unit difference explicit via a
wrapper function.

Fixes: d0eb20a863ba ("sd: Optimal I/O size is in bytes, not sectors")
Cc: stable@vger.kernel.org # 4.4+
Reported-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Andrew Patterson <andrew.patterson@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index f459dff30512..60bff78e9ead 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2867,10 +2867,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
 	if (sdkp->opt_xfer_blocks &&
 	    sdkp->opt_xfer_blocks <= dev_max &&
 	    sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
-	    sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_SIZE)
-		rw_max = q->limits.io_opt =
-			sdkp->opt_xfer_blocks * sdp->sector_size;
-	else
+	    logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_SIZE) {
+		q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
+		rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
+	} else
 		rw_max = BLK_DEF_MAX_SECTORS;
 
 	/* Combine with controller limits */
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 654630bb7d0e..765a6f1ac1b7 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -151,6 +151,11 @@ static inline sector_t logical_to_sectors(struct scsi_device *sdev, sector_t blo
 	return blocks << (ilog2(sdev->sector_size) - 9);
 }
 
+static inline unsigned int logical_to_bytes(struct scsi_device *sdev, sector_t blocks)
+{
+	return blocks * sdev->sector_size;
+}
+
 /*
  * A DIF-capable target device can be formatted with different
  * protection schemes.  Currently 0 through 3 are defined: