commit c5ae77d37bde1e9b2db48026f6a483a7fd08c076
Author: James Bottomley <[EMAIL PROTECTED]>
Date:   Sat Feb 2 16:06:23 2008 -0600

    SCSI: sd: handle bad lba in sense information
    
    patch 366c246de9cec909c5eba4f784c92d1e75b4dc38 in mainline.
    
    Some devices report medium error locations incorrectly.  Add guards to
    make sure the reported bad lba is actually in the request that caused
    it.  Additionally remove the large case statment for sector sizes and
    replace it with the proper u64 divisions.
    
    Tested-by: Mike Snitzer <[EMAIL PROTECTED]>
    Cc: Stable Tree <[EMAIL PROTECTED]>
    Cc: Tony Battersby <[EMAIL PROTECTED]>
    Signed-off-by: James Bottomley <[EMAIL PROTECTED]>
    Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a69b155..cfd859a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -907,6 +907,7 @@ static int sd_done(struct scsi_cmnd *SCpnt)
        unsigned int xfer_size = SCpnt->request_bufflen;
        unsigned int good_bytes = result ? 0 : xfer_size;
        u64 start_lba = SCpnt->request->sector;
+       u64 end_lba = SCpnt->request->sector + (xfer_size / 512);
        u64 bad_lba;
        struct scsi_sense_hdr sshdr;
        int sense_valid = 0;
@@ -945,26 +946,23 @@ static int sd_done(struct scsi_cmnd *SCpnt)
                        goto out;
                if (xfer_size <= SCpnt->device->sector_size)
                        goto out;
-               switch (SCpnt->device->sector_size) {
-               case 256:
+               if (SCpnt->device->sector_size < 512) {
+                       /* only legitimate sector_size here is 256 */
                        start_lba <<= 1;
-                       break;
-               case 512:
-                       break;
-               case 1024:
-                       start_lba >>= 1;
-                       break;
-               case 2048:
-                       start_lba >>= 2;
-                       break;
-               case 4096:
-                       start_lba >>= 3;
-                       break;
-               default:
-                       /* Print something here with limiting frequency. */
-                       goto out;
-                       break;
+                       end_lba <<= 1;
+               } else {
+                       /* be careful ... don't want any overflows */
+                       u64 factor = SCpnt->device->sector_size / 512;
+                       do_div(start_lba, factor);
+                       do_div(end_lba, factor);
                }
+
+               if (bad_lba < start_lba  || bad_lba >= end_lba)
+                       /* the bad lba was reported incorrectly, we have
+                        * no idea where the error is
+                        */
+                       goto out;
+
                /* This computation should always be done in terms of
                 * the resolution of the device's medium.
                 */
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