mptfusion: tweak null pointer checks

Fixes the following smatch warnings:

  drivers/message/fusion/mptbase.c:652 mptbase_reply() warn: variable
    dereferenced before check 'reply' (see line 639)

      [JL: No-brainer, the enclosing switch statement dereferences
       reply, so we can't get here unless reply is valid.]

  drivers/message/fusion/mptsas.c:1255 mptsas_taskmgmt_complete() error:
    we previously assumed 'pScsiTmReply' could be null (see line 1227)

      [HCH: Reading the code in mptsas_taskmgmt_complete it's pretty
       obvious that it can't do anything useful if mr/pScsiTmReply are
       NULL, so I suspect it would be best to just return at the
       beginning of the function.

       I'd love to understand if it actually could ever be zero, which I
       doubt.  Maybe the LSI people can shed some light on that?]

  drivers/message/fusion/mptsas.c:3888 mptsas_not_responding_devices()
    error: we previously assumed 'port_info->phy_info' could be null
    (see line 3875)

      [HCH: It's pretty obvious from reading mptsas_sas_io_unit_pg0 that
       we never register a port_info with a NULL phy_info in the lists,
       so all NULL checks on it could be deleted.]

  drivers/message/fusion/mptscsih.c:1284 mptscsih_info() error:
    we previously assumed 'h' could be null (see line 1274)

      [HCH: shost_priv can't return NULL, so the if (h) should be
       removed.]

  drivers/message/fusion/mptscsih.c:1388 mptscsih_qcmd() error: we
    previously assumed 'vdevice' could be null (see line 1373)

      [HCH: vdevice can't ever be NULL here, it's allocated in
       ->slave_alloc and thus guaranteed to be around when
       ->queuecommand is called.]

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

3 files changed, 37 insertions, 44 deletions

diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
index 9d4c7825a5f..a896d948b79 100644
--- a/drivers/message/fusion/mptbase.c
+++ b/drivers/message/fusion/mptbase.c
@@ -649,12 +649,10 @@ mptbase_reply(MPT_ADAPTER *ioc, MPT_FRAME_HDR *req, MPT_FRAME_HDR *reply)
 	case MPI_FUNCTION_CONFIG:
 	case MPI_FUNCTION_SAS_IO_UNIT_CONTROL:
 		ioc->mptbase_cmds.status |= MPT_MGMT_STATUS_COMMAND_GOOD;
-		if (reply) {
-			ioc->mptbase_cmds.status |= MPT_MGMT_STATUS_RF_VALID;
-			memcpy(ioc->mptbase_cmds.reply, reply,
-			    min(MPT_DEFAULT_FRAME_SIZE,
-				4 * reply->u.reply.MsgLength));
-		}
+		ioc->mptbase_cmds.status |= MPT_MGMT_STATUS_RF_VALID;
+		memcpy(ioc->mptbase_cmds.reply, reply,
+		    min(MPT_DEFAULT_FRAME_SIZE,
+			4 * reply->u.reply.MsgLength));
 		if (ioc->mptbase_cmds.status & MPT_MGMT_STATUS_PENDING) {
 			ioc->mptbase_cmds.status &= ~MPT_MGMT_STATUS_PENDING;
 			complete(&ioc->mptbase_cmds.done);
diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index b0b74c4d264..0707fa2c701 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -1203,27 +1203,28 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *ioc, MPT_FRAME_HDR *mf, MPT_FRAME_HDR *mr)
 	    "(mf = %p, mr = %p)\n", ioc->name, mf, mr));
 
 	pScsiTmReply = (SCSITaskMgmtReply_t *)mr;
-	if (pScsiTmReply) {
-		dtmprintk(ioc, printk(MYIOC_s_DEBUG_FMT
-		    "\tTaskMgmt completed: fw_channel = %d, fw_id = %d,\n"
-		    "\ttask_type = 0x%02X, iocstatus = 0x%04X "
-		    "loginfo = 0x%08X,\n\tresponse_code = 0x%02X, "
-		    "term_cmnds = %d\n", ioc->name,
-		    pScsiTmReply->Bus, pScsiTmReply->TargetID,
-		    pScsiTmReply->TaskType,
-		    le16_to_cpu(pScsiTmReply->IOCStatus),
-		    le32_to_cpu(pScsiTmReply->IOCLogInfo),
-		    pScsiTmReply->ResponseCode,
-		    le32_to_cpu(pScsiTmReply->TerminationCount)));
-
-		if (pScsiTmReply->ResponseCode)
-			mptscsih_taskmgmt_response_code(ioc,
-			pScsiTmReply->ResponseCode);
-	}
-
-	if (pScsiTmReply && (pScsiTmReply->TaskType ==
+	if (!pScsiTmReply)
+		return 0;
+
+	dtmprintk(ioc, printk(MYIOC_s_DEBUG_FMT
+	    "\tTaskMgmt completed: fw_channel = %d, fw_id = %d,\n"
+	    "\ttask_type = 0x%02X, iocstatus = 0x%04X "
+	    "loginfo = 0x%08X,\n\tresponse_code = 0x%02X, "
+	    "term_cmnds = %d\n", ioc->name,
+	    pScsiTmReply->Bus, pScsiTmReply->TargetID,
+	    pScsiTmReply->TaskType,
+	    le16_to_cpu(pScsiTmReply->IOCStatus),
+	    le32_to_cpu(pScsiTmReply->IOCLogInfo),
+	    pScsiTmReply->ResponseCode,
+	    le32_to_cpu(pScsiTmReply->TerminationCount)));
+
+	if (pScsiTmReply->ResponseCode)
+		mptscsih_taskmgmt_response_code(ioc,
+		pScsiTmReply->ResponseCode);
+
+	if (pScsiTmReply->TaskType ==
 	    MPI_SCSITASKMGMT_TASKTYPE_QUERY_TASK || pScsiTmReply->TaskType ==
-	     MPI_SCSITASKMGMT_TASKTYPE_ABRT_TASK_SET)) {
+	     MPI_SCSITASKMGMT_TASKTYPE_ABRT_TASK_SET) {
 		ioc->taskmgmt_cmds.status |= MPT_MGMT_STATUS_COMMAND_GOOD;
 		ioc->taskmgmt_cmds.status |= MPT_MGMT_STATUS_RF_VALID;
 		memcpy(ioc->taskmgmt_cmds.reply, mr,
@@ -3853,10 +3854,8 @@ retry_page:
 			phy_info = mptsas_find_phyinfo_by_sas_address(ioc,
 					sas_info->sas_address);
 
-			if (phy_info) {
-				mptsas_del_end_device(ioc, phy_info);
-				goto redo_device_scan;
-			}
+			mptsas_del_end_device(ioc, phy_info);
+			goto redo_device_scan;
 		} else
 			mptsas_volume_delete(ioc, sas_info->fw.id);
 	}
@@ -3867,9 +3866,8 @@ retry_page:
  redo_expander_scan:
 	list_for_each_entry(port_info, &ioc->sas_topology, list) {
 
-		if (port_info->phy_info &&
-		    (!(port_info->phy_info[0].identify.device_info &
-		    MPI_SAS_DEVICE_INFO_SMP_TARGET)))
+		if (!(port_info->phy_info[0].identify.device_info &
+		    MPI_SAS_DEVICE_INFO_SMP_TARGET))
 			continue;
 		found_expander = 0;
 		handle = 0xFFFF;
diff --git a/drivers/message/fusion/mptscsih.c b/drivers/message/fusion/mptscsih.c
index 39e56680308..e7dcb258336 100644
--- a/drivers/message/fusion/mptscsih.c
+++ b/drivers/message/fusion/mptscsih.c
@@ -1271,15 +1271,13 @@ mptscsih_info(struct Scsi_Host *SChost)
 
 	h = shost_priv(SChost);
 
-	if (h) {
-		if (h->info_kbuf == NULL)
-			if ((h->info_kbuf = kmalloc(0x1000 /* 4Kb */, GFP_KERNEL)) == NULL)
-				return h->info_kbuf;
-		h->info_kbuf[0] = '\0';
-
-		mpt_print_ioc_summary(h->ioc, h->info_kbuf, &size, 0, 0);
-		h->info_kbuf[size-1] = '\0';
-	}
+	if (h->info_kbuf == NULL)
+		if ((h->info_kbuf = kmalloc(0x1000 /* 4Kb */, GFP_KERNEL)) == NULL)
+			return h->info_kbuf;
+	h->info_kbuf[0] = '\0';
+
+	mpt_print_ioc_summary(h->ioc, h->info_kbuf, &size, 0, 0);
+	h->info_kbuf[size-1] = '\0';
 
 	return h->info_kbuf;
 }
@@ -1368,8 +1366,7 @@ mptscsih_qcmd(struct scsi_cmnd *SCpnt)
 	/* Default to untagged. Once a target structure has been allocated,
 	 * use the Inquiry data to determine if device supports tagged.
 	 */
-	if (vdevice
-	    && (vdevice->vtarget->tflags & MPT_TARGET_FLAGS_Q_YES)
+	if ((vdevice->vtarget->tflags & MPT_TARGET_FLAGS_Q_YES)
 	    && (SCpnt->device->tagged_supported)) {
 		scsictl = scsidir | MPI_SCSIIO_CONTROL_SIMPLEQ;
 		if (SCpnt->request && SCpnt->request->ioprio) {