Patch "sd: Disable support for 256 byte/sector disks" has been added to the 4.0-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    sd: Disable support for 256 byte/sector disks

to the 4.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     sd-disable-support-for-256-byte-sector-disks.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 74856fbf441929918c49ff262ace9835048e4e6a Mon Sep 17 00:00:00 2001
From: Mark Hounschell <dmarkh@cfl.rr.com>
Date: Wed, 13 May 2015 10:49:09 +0200
Subject: sd: Disable support for 256 byte/sector disks

From: Mark Hounschell <dmarkh@cfl.rr.com>

commit 74856fbf441929918c49ff262ace9835048e4e6a upstream.

256 bytes per sector support has been broken since 2.6.X,
and no-one stepped up to fix this.
So disable support for it.

Signed-off-by: Mark Hounschell <dmarkh@cfl.rr.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/sd.c |   19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1624,6 +1624,7 @@ static unsigned int sd_completed_bytes(s
 {
 	u64 start_lba = blk_rq_pos(scmd->request);
 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
+	u64 factor = scmd->device->sector_size / 512;
 	u64 bad_lba;
 	int info_valid;
 	/*
@@ -1645,16 +1646,9 @@ static unsigned int sd_completed_bytes(s
 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
 		return 0;
 
-	if (scmd->device->sector_size < 512) {
-		/* only legitimate sector_size here is 256 */
-		start_lba <<= 1;
-		end_lba <<= 1;
-	} else {
-		/* be careful ... don't want any overflows */
-		unsigned int factor = scmd->device->sector_size / 512;
-		do_div(start_lba, factor);
-		do_div(end_lba, factor);
-	}
+	/* be careful ... don't want any overflows */
+	do_div(start_lba, factor);
+	do_div(end_lba, factor);
 
 	/* The bad lba was reported incorrectly, we have no idea where
 	 * the error is.
@@ -2212,8 +2206,7 @@ got_data:
 	if (sector_size != 512 &&
 	    sector_size != 1024 &&
 	    sector_size != 2048 &&
-	    sector_size != 4096 &&
-	    sector_size != 256) {
+	    sector_size != 4096) {
 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
 			  sector_size);
 		/*
@@ -2268,8 +2261,6 @@ got_data:
 		sdkp->capacity <<= 2;
 	else if (sector_size == 1024)
 		sdkp->capacity <<= 1;
-	else if (sector_size == 256)
-		sdkp->capacity >>= 1;
 
 	blk_queue_physical_block_size(sdp->request_queue,
 				      sdkp->physical_block_size);


Patches currently in stable-queue which might be from dmarkh@cfl.rr.com are

queue-4.0/sd-disable-support-for-256-byte-sector-disks.patch