[SCSI] 3w-xxxx: fix oops caused by incorrect REQUEST_SENSE handling

3w-xxxx emulates a REQUEST_SENSE response by simply returning nothing.
Unfortunately, it's assuming that the REQUEST_SENSE command is
implemented with use_sg == 0, which is no longer the case.  The oops
occurs because it's clearing the scatterlist in request_buffer instead
of the memory region.

This is fixed by using tw_transfer_internal() to transfer correctly to
the scatterlist.

Acked-by: adam radford <aradford@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index bf5d63e1beee..656bdb1352d8 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -1864,10 +1864,17 @@ static int tw_scsiop_read_write(TW_Device_Extension *tw_dev, int request_id)
 /* This function will handle the request sense scsi command */
 static int tw_scsiop_request_sense(TW_Device_Extension *tw_dev, int request_id)
 {
+        char request_buffer[18];
+
         dprintk(KERN_NOTICE "3w-xxxx: tw_scsiop_request_sense()\n");
 
-        /* For now we just zero the request buffer */
-        memset(tw_dev->srb[request_id]->request_buffer, 0, tw_dev->srb[request_id]->request_bufflen);
+        memset(request_buffer, 0, sizeof(request_buffer));
+        request_buffer[0] = 0x70; /* Immediate fixed format */
+        request_buffer[7] = 10; /* minimum size per SPC: 18 bytes */
+        /* leave all other fields zero, giving effectively NO_SENSE return */
+        tw_transfer_internal(tw_dev, request_id, request_buffer,
+                             sizeof(request_buffer));
+
         tw_dev->state[request_id] = TW_S_COMPLETED;
         tw_state_request_finish(tw_dev, request_id);