scsi: qla2xxx: target: Improve checks in qlt_xmit_response() / qlt_rdy_to_xfer()

Similar fixes to both functions:

qlt_xmit_response:

 - If the cmd cannot be processed, remember to call ->free_cmd() to
   prevent the target-mode midlevel from seeing a cmd lockup.

 - Do not try to send the response if the exchange has been terminated.

 - Check for chip reset once after lock instead of both before and after
   lock.

 - Give errors from qlt_pre_xmit_response() a lower priority to
   compensate for removing the first check for chip reset.

qlt_rdy_to_xfer:

 - Check for chip reset after lock instead of before lock to avoid
   races.

 - Do not try to receive data if the exchange has been terminated.

 - Give errors from qlt_pci_map_calc_cnt() a lower priority to
   compensate for moving the check for chip reset.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Link: https://patch.msgid.link/cd6ccd31-33fa-4454-be36-507bf578a546@cybernetics.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: abattersby

drivers/scsi/qla2xxx/qla_target.c

@@ -3206,46 +3206,47 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type,
 	uint32_t full_req_cnt = 0;
 	unsigned long flags = 0;
 	int res;
-
-	if (!qpair->fw_started || (cmd->reset_count != qpair->chip_reset) ||
-	    (cmd->sess && cmd->sess->deleted)) {
-		cmd->state = QLA_TGT_STATE_PROCESSED;
-		return 0;
-	}
+	int pre_xmit_res;
 
 	ql_dbg_qp(ql_dbg_tgt, qpair, 0xe018,
 	    "is_send_status=%d, cmd->bufflen=%d, cmd->sg_cnt=%d, cmd->dma_data_direction=%d se_cmd[%p] qp %d\n",
 	    (xmit_type & QLA_TGT_XMIT_STATUS) ?
 	    1 : 0, cmd->bufflen, cmd->sg_cnt, cmd->dma_data_direction,
 	    &cmd->se_cmd, qpair->id);
 
-	res = qlt_pre_xmit_response(cmd, &prm, xmit_type, scsi_status,
+	pre_xmit_res = qlt_pre_xmit_response(cmd, &prm, xmit_type, scsi_status,
 	    &full_req_cnt);
-	if (unlikely(res != 0)) {
-		return res;
-	}
+	/*
+	 * Check pre_xmit_res later because we want to check other errors
+	 * first.
+	 */
 
 	spin_lock_irqsave(qpair->qp_lock_ptr, flags);
 
+	if (unlikely(cmd->sent_term_exchg ||
+		     cmd->sess->deleted ||
+		     !qpair->fw_started ||
+		     cmd->reset_count != qpair->chip_reset)) {
+		ql_dbg(ql_dbg_tgt_mgt, vha, 0xe101,
+		    "qla_target(%d): tag %lld: skipping send response for aborted cmd\n",
+		    vha->vp_idx, cmd->se_cmd.tag);
+		qlt_unmap_sg(vha, cmd);
+		cmd->state = QLA_TGT_STATE_PROCESSED;
+		vha->hw->tgt.tgt_ops->free_cmd(cmd);
+		spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
+		return 0;
+	}
+
+	/* Check for errors from qlt_pre_xmit_response(). */
+	res = pre_xmit_res;
+	if (unlikely(res))
+		goto out_unmap_unlock;
+
 	if (xmit_type == QLA_TGT_XMIT_STATUS)
 		qpair->tgt_counters.core_qla_snd_status++;
 	else
 		qpair->tgt_counters.core_qla_que_buf++;
 
-	if (!qpair->fw_started || cmd->reset_count != qpair->chip_reset) {
-		/*
-		 * Either the port is not online or this request was from
-		 * previous life, just abort the processing.
-		 */
-		cmd->state = QLA_TGT_STATE_PROCESSED;
-		ql_dbg_qp(ql_dbg_async, qpair, 0xe101,
-			"RESET-RSP online/active/old-count/new-count = %d/%d/%d/%d.\n",
-			vha->flags.online, qla2x00_reset_active(vha),
-			cmd->reset_count, qpair->chip_reset);
-		res = 0;
-		goto out_unmap_unlock;
-	}
-
 	/* Does F/W have an IOCBs for this request */
 	res = qlt_check_reserve_free_req(qpair, full_req_cnt);
 	if (unlikely(res))
@@ -3360,6 +3361,7 @@ int qlt_rdy_to_xfer(struct qla_tgt_cmd *cmd)
 	struct qla_tgt_prm prm;
 	unsigned long flags = 0;
 	int res = 0;
+	int pci_map_res;
 	struct qla_qpair *qpair = cmd->qpair;
 
 	memset(&prm, 0, sizeof(prm));
@@ -3368,28 +3370,36 @@ int qlt_rdy_to_xfer(struct qla_tgt_cmd *cmd)
 	prm.sg = NULL;
 	prm.req_cnt = 1;
 
-	if (!qpair->fw_started || (cmd->reset_count != qpair->chip_reset) ||
-	    (cmd->sess && cmd->sess->deleted)) {
-		/*
-		 * Either the port is not online or this request was from
-		 * previous life, just abort the processing.
-		 */
+	/* Calculate number of entries and segments required */
+	pci_map_res = qlt_pci_map_calc_cnt(&prm);
+	/*
+	 * Check pci_map_res later because we want to check other errors first.
+	 */
+
+	spin_lock_irqsave(qpair->qp_lock_ptr, flags);
+
+	if (unlikely(cmd->sent_term_exchg ||
+		     cmd->sess->deleted ||
+		     !qpair->fw_started ||
+		     cmd->reset_count != qpair->chip_reset)) {
+		ql_dbg(ql_dbg_tgt_mgt, vha, 0xe102,
+		    "qla_target(%d): tag %lld: skipping data-out for aborted cmd\n",
+		    vha->vp_idx, cmd->se_cmd.tag);
+		qlt_unmap_sg(vha, cmd);
 		cmd->aborted = 1;
 		cmd->write_data_transferred = 0;
 		cmd->state = QLA_TGT_STATE_DATA_IN;
 		vha->hw->tgt.tgt_ops->handle_data(cmd);
-		ql_dbg_qp(ql_dbg_async, qpair, 0xe102,
-			"RESET-XFR online/active/old-count/new-count = %d/%d/%d/%d.\n",
-			vha->flags.online, qla2x00_reset_active(vha),
-			cmd->reset_count, qpair->chip_reset);
+		spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
 		return 0;
 	}
 
-	/* Calculate number of entries and segments required */
-	if (qlt_pci_map_calc_cnt(&prm) != 0)
-		return -EAGAIN;
+	/* Check for errors from qlt_pci_map_calc_cnt(). */
+	if (unlikely(pci_map_res != 0)) {
+		res = -EAGAIN;
+		goto out_unlock_free_unmap;
+	}
 
-	spin_lock_irqsave(qpair->qp_lock_ptr, flags);
 	/* Does F/W have an IOCBs for this request */
 	res = qlt_check_reserve_free_req(qpair, prm.req_cnt);
 	if (res != 0)