[SCSI] be2iscsi: Fix returning Failure when MBX fails with Insufficient buffer error

When MBX command fails with insufficent buffer, check for the
response lenght returned. Return success if response length
is non-zero value which indicates valid data.
Signed-off-by: Minh Tran <minhduc.tran@emulex.com>
Signed-off-by: John Soni Jose <sony.john-n@emulex.com>
Signed-off-by: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/be2iscsi/be_cmds.c

@@ -155,6 +155,7 @@ int beiscsi_mccq_compl(struct beiscsi_hba *phba,
 	uint16_t status = 0, addl_status = 0, wrb_num = 0;
 	struct be_mcc_wrb *temp_wrb;
 	struct be_cmd_req_hdr *ioctl_hdr;
+	struct be_cmd_resp_hdr *ioctl_resp_hdr;
 	struct be_queue_info *mccq = &phba->ctrl.mcc_obj.q;
 
 	if (beiscsi_error(phba))
@@ -204,6 +205,12 @@ int beiscsi_mccq_compl(struct beiscsi_hba *phba,
 			    ioctl_hdr->subsystem,
 			    ioctl_hdr->opcode,
 			    status, addl_status);
+
+		if (status == MCC_STATUS_INSUFFICIENT_BUFFER) {
+			ioctl_resp_hdr = (struct be_cmd_resp_hdr *) ioctl_hdr;
+			if (ioctl_resp_hdr->response_length)
+				goto release_mcc_tag;
+		}
 		rc = -EAGAIN;
 	}
 
@@ -267,6 +274,7 @@ static int be_mcc_compl_process(struct be_ctrl_info *ctrl,
 	struct be_mcc_wrb *wrb = wrb_from_mbox(&ctrl->mbox_mem);
 	struct beiscsi_hba *phba = pci_get_drvdata(ctrl->pdev);
 	struct be_cmd_req_hdr *hdr = embedded_payload(wrb);
+	struct be_cmd_resp_hdr *resp_hdr;
 
 	be_dws_le_to_cpu(compl, 4);
 
@@ -284,6 +292,11 @@ static int be_mcc_compl_process(struct be_ctrl_info *ctrl,
 			    hdr->subsystem, hdr->opcode,
 			    compl_status, extd_status);
 
+		if (compl_status == MCC_STATUS_INSUFFICIENT_BUFFER) {
+			resp_hdr = (struct be_cmd_resp_hdr *) hdr;
+			if (resp_hdr->response_length)
+				return 0;
+		}
 		return -EBUSY;
 	}
 	return 0;

drivers/scsi/be2iscsi/be_cmds.h

@@ -52,6 +52,10 @@ struct be_mcc_wrb {
 
 /* Completion Status */
 #define MCC_STATUS_SUCCESS 0x0
+#define MCC_STATUS_FAILED 0x1
+#define MCC_STATUS_ILLEGAL_REQUEST 0x2
+#define MCC_STATUS_ILLEGAL_FIELD 0x3
+#define MCC_STATUS_INSUFFICIENT_BUFFER 0x4
 
 #define CQE_STATUS_COMPL_MASK 0xFFFF
 #define CQE_STATUS_COMPL_SHIFT 0	/* bits 0 - 15 */