[PATCH 1/5] scsi_error: code cleanup before refactoring of scsi_send_eh_cmnd()

[Boaz Harrosh <bharrosh@panasas.com>]

  - regrouped variables for easier reviewing of next patch
  - Support of cmnd==NULL in call to scsi_send_eh_cmnd()
  - In the REQUEST_SENSE case set cmnd[4] to the size of
    sense_buffer. It was previously set by caller but needed
    to be in sync with sense_buffer size.
  - Also save/restore resid of faild command.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
---
 drivers/scsi/scsi_error.c |   37 +++++++++++++++++++++++--------------
 1 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index c8e351f..0bcfbe5 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -611,17 +611,20 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 {
 	struct scsi_device *sdev = scmd->device;
 	struct Scsi_Host *shost = sdev->host;
-	int old_result = scmd->result;
 	DECLARE_COMPLETION_ONSTACK(done);
 	unsigned long timeleft;
 	unsigned long flags;
-	struct scatterlist sgl;
+
+	unsigned char old_cmd_len;
 	unsigned char old_cmnd[MAX_COMMAND_SIZE];
 	enum dma_data_direction old_data_direction;
-	unsigned short old_use_sg;
-	unsigned char old_cmd_len;
 	unsigned old_bufflen;
 	void *old_buffer;
+	unsigned short old_use_sg;
+	int old_resid;
+	int old_result;
+
+	struct scatterlist sgl;
 	int rtn;
 
 	/*
@@ -631,15 +634,20 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 	 * we will need to restore these values prior to running the actual
 	 * command.
 	 */
-	old_buffer = scmd->request_buffer;
-	old_bufflen = scmd->request_bufflen;
+	old_cmd_len = scmd->cmd_len;
 	memcpy(old_cmnd, scmd->cmnd, sizeof(scmd->cmnd));
 	old_data_direction = scmd->sc_data_direction;
-	old_cmd_len = scmd->cmd_len;
+	old_bufflen = scmd->request_bufflen;
+	old_buffer = scmd->request_buffer;
 	old_use_sg = scmd->use_sg;
+	old_resid = scmd->resid;
+	old_result = scmd->result;
 
-	memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
-	memcpy(scmd->cmnd, cmnd, cmnd_size);
+	if (cmnd) {
+		memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
+		memcpy(scmd->cmnd, cmnd, cmnd_size);
+		scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
+	}
 
 	if (copy_sense) {
 		sg_init_one(&sgl, scmd->sense_buffer,
@@ -649,6 +657,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 		scmd->request_bufflen = sgl.length;
 		scmd->request_buffer = &sgl;
 		scmd->use_sg = 1;
+		scmd->cmnd[4] = sgl.length;
 	} else {
 		scmd->request_buffer = NULL;
 		scmd->request_bufflen = 0;
@@ -657,7 +666,6 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 	}
 
 	scmd->underflow = 0;
-	scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
 
 	if (sdev->scsi_level <= SCSI_2)
 		scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
@@ -716,12 +724,13 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 	/*
 	 * Restore original data
 	 */
-	scmd->request_buffer = old_buffer;
-	scmd->request_bufflen = old_bufflen;
+	scmd->cmd_len = old_cmd_len;
 	memcpy(scmd->cmnd, old_cmnd, sizeof(scmd->cmnd));
 	scmd->sc_data_direction = old_data_direction;
-	scmd->cmd_len = old_cmd_len;
+	scmd->request_bufflen = old_bufflen;
+	scmd->request_buffer = old_buffer;
 	scmd->use_sg = old_use_sg;
+	scmd->resid = old_resid;
 	scmd->result = old_result;
 	return rtn;
 }
@@ -738,7 +747,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 static int scsi_request_sense(struct scsi_cmnd *scmd)
 {
 	static unsigned char generic_sense[6] =
-		{REQUEST_SENSE, 0, 0, 0, 252, 0};
+		{REQUEST_SENSE, 0, 0, 0, 0, 0};
 
 	return scsi_send_eh_cmnd(scmd, generic_sense, 6, SENSE_TIMEOUT, 1);
 }
-- 
1.5.3.1