scsi: qedf: Fix race between ELS completion and flushing ELS request

Fix race between ELS completion and flushing ELS request.

Link: https://lore.kernel.org/r/20200807110656.19965-8-jhasan@marvell.comSigned-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Javed Hasan <jhasan@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qedf/qedf_els.c

@@ -143,6 +143,7 @@ void qedf_process_els_compl(struct qedf_ctx *qedf, struct fcoe_cqe *cqe,
 	struct qedf_ioreq *els_req)
 {
 	struct fcoe_cqe_midpath_info *mp_info;
+	struct qedf_rport *fcport;
 
 	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered with xid = 0x%x"
 		   " cmd_type = %d.\n", els_req->xid, els_req->cmd_type);
@@ -156,6 +157,19 @@ void qedf_process_els_compl(struct qedf_ctx *qedf, struct fcoe_cqe *cqe,
 		return;
 	}
 
+	fcport = els_req->fcport;
+
+	/* When flush is active,
+	 * let the cmds be completed from the cleanup context
+	 */
+	if (test_bit(QEDF_RPORT_IN_TARGET_RESET, &fcport->flags) ||
+		test_bit(QEDF_RPORT_IN_LUN_RESET, &fcport->flags)) {
+		QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_IO,
+			"Dropping ELS completion xid=0x%x as fcport is flushing",
+			els_req->xid);
+		return;
+	}
+
 	clear_bit(QEDF_CMD_OUTSTANDING, &els_req->flags);
 
 	/* Kill the ELS timer */

drivers/scsi/qedf/qedf_io.c

@@ -1562,6 +1562,8 @@ static void qedf_flush_els_req(struct qedf_ctx *qedf,
 	 */
 	els_req->event = QEDF_IOREQ_EV_ELS_FLUSH;
 
+	clear_bit(QEDF_CMD_OUTSTANDING, &els_req->flags);
+
 	/* Cancel the timer */
 	cancel_delayed_work_sync(&els_req->timeout_work);