sd: Disable support for 256 byte/sector disks

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>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Odin.com>

1 files changed, 5 insertions, 14 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 79beebf53302..7f9d65fe4fd9 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1600,6 +1600,7 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
 {
         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;
         /*
@@ -1621,16 +1622,9 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
         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.
@@ -2188,8 +2182,7 @@ 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);
                 /*
@@ -2244,8 +2237,6 @@ 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);