[SCSI] usb: transport - convert to accessors and !use_sg code path removal

  - This patch depends on:
    usb: transport.c use scsi_eh API in REQUEST_SENSE execution

  - Use scsi data accessors and remove of !use_sg code path.
  - New usb_stor_bulk_srb() for use by drivers

[jejb: updated with corrective fix.

had a bug in residual handling in the new usb_stor_bulk_srb()
function.  Found by Gabriel C. in -mm tree.

Tested-by: Gabriel C <nix.or.die@googlemail.com>
]

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: Matthew Dharm <mdharm-scsi@one-eyed-alien.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 30 insertions, 17 deletions

diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index c646750ccc30..d9f4912f873d 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -459,6 +459,22 @@ static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
 }
 
 /*
+ * Common used function. Transfer a complete command
+ * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
+ */
+int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
+                      struct scsi_cmnd* srb)
+{
+        unsigned int partial;
+        int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
+                                      scsi_sg_count(srb), scsi_bufflen(srb),
+                                      &partial);
+
+        scsi_set_resid(srb, scsi_bufflen(srb) - partial);
+        return result;
+}
+
+/*
  * Transfer an entire SCSI command's worth of data payload over the bulk
  * pipe.
  *
@@ -508,7 +524,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
         int result;
 
         /* send the command to the transport layer */
-        srb->resid = 0;
+        scsi_set_resid(srb, 0);
         result = us->transport(srb, us);
 
         /* if the command gets aborted by the higher layers, we need to
@@ -568,7 +584,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
          * A short transfer on a command where we don't expect it
          * is unusual, but it doesn't mean we need to auto-sense.
          */
-        if ((srb->resid > 0) &&
+        if ((scsi_get_resid(srb) > 0) &&
             !((srb->cmnd[0] == REQUEST_SENSE) ||
               (srb->cmnd[0] == INQUIRY) ||
               (srb->cmnd[0] == MODE_SENSE) ||
@@ -593,7 +609,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
                         srb->cmd_len = 12;
 
                 /* issue the auto-sense command */
-                srb->resid = 0;
+                scsi_set_resid(srb, 0);
                 temp_result = us->transport(us->srb, us);
 
                 /* let's clean up right away */
@@ -649,7 +665,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 
         /* Did we transfer less than the minimum amount required? */
         if (srb->result == SAM_STAT_GOOD &&
-                        srb->request_bufflen - srb->resid < srb->underflow)
+                        scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
                 srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24);
 
         return;
@@ -708,7 +724,7 @@ void usb_stor_stop_transport(struct us_data *us)
 
 int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us)
 {
-        unsigned int transfer_length = srb->request_bufflen;
+        unsigned int transfer_length = scsi_bufflen(srb);
         unsigned int pipe = 0;
         int result;
 
@@ -737,9 +753,7 @@ int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us)
         if (transfer_length) {
                 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
                                 us->recv_bulk_pipe : us->send_bulk_pipe;
-                result = usb_stor_bulk_transfer_sg(us, pipe,
-                                        srb->request_buffer, transfer_length,
-                                        srb->use_sg, &srb->resid);
+                result = usb_stor_bulk_srb(us, pipe, srb);
                 US_DEBUGP("CBI data stage result is 0x%x\n", result);
 
                 /* if we stalled the data transfer it means command failed */
@@ -808,7 +822,7 @@ int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us)
  */
 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
 {
-        unsigned int transfer_length = srb->request_bufflen;
+        unsigned int transfer_length = scsi_bufflen(srb);
         int result;
 
         /* COMMAND STAGE */
@@ -836,9 +850,7 @@ int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
         if (transfer_length) {
                 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
                                 us->recv_bulk_pipe : us->send_bulk_pipe;
-                result = usb_stor_bulk_transfer_sg(us, pipe,
-                                        srb->request_buffer, transfer_length,
-                                        srb->use_sg, &srb->resid);
+                result = usb_stor_bulk_srb(us, pipe, srb);
                 US_DEBUGP("CB data stage result is 0x%x\n", result);
 
                 /* if we stalled the data transfer it means command failed */
@@ -904,7 +916,7 @@ int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
 {
         struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
         struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
-        unsigned int transfer_length = srb->request_bufflen;
+        unsigned int transfer_length = scsi_bufflen(srb);
         unsigned int residue;
         int result;
         int fake_sense = 0;
@@ -955,9 +967,7 @@ int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
         if (transfer_length) {
                 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
                                 us->recv_bulk_pipe : us->send_bulk_pipe;
-                result = usb_stor_bulk_transfer_sg(us, pipe,
-                                        srb->request_buffer, transfer_length,
-                                        srb->use_sg, &srb->resid);
+                result = usb_stor_bulk_srb(us, pipe, srb);
                 US_DEBUGP("Bulk data transfer result 0x%x\n", result);
                 if (result == USB_STOR_XFER_ERROR)
                         return USB_STOR_TRANSPORT_ERROR;
@@ -1036,7 +1046,8 @@ int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
         if (residue) {
                 if (!(us->flags & US_FL_IGNORE_RESIDUE)) {
                         residue = min(residue, transfer_length);
-                        srb->resid = max(srb->resid, (int) residue);
+                        scsi_set_resid(srb, max(scsi_get_resid(srb),
+                                                               (int) residue));
                 }
         }
 
diff --git a/drivers/usb/storage/transport.h b/drivers/usb/storage/transport.h
index 633a715850a4..ada7c2f43f84 100644
--- a/drivers/usb/storage/transport.h
+++ b/drivers/usb/storage/transport.h
@@ -139,6 +139,8 @@ extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
                 void *buf, unsigned int length, unsigned int *act_len);
 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
                 void *buf, unsigned int length, int use_sg, int *residual);
+extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
+                struct scsi_cmnd* srb);
 
 extern int usb_stor_port_reset(struct us_data *us);
 #endif