scsi: qedi: Fix race during abort timeouts

If the SCSI cmd completes after qedi_tmf_work calls iscsi_itt_to_task then
the qedi qedi_cmd->task_id could be freed and used for another cmd. If we
then call qedi_iscsi_cleanup_task with that task_id we will be cleaning up
the wrong cmd.

Wait to release the task_id until the last put has been done on the
iscsi_task. Because libiscsi grabs a ref to the task when sending the
abort, we know that for the non-abort timeout case that the task_id we are
referencing is for the cmd that was supposed to be aborted.

A latter commit will fix the case where the abort times out while we are
running qedi_tmf_work.

Link: https://lore.kernel.org/r/20210525181821.7617-21-michael.christie@oracle.com
Reviewed-by: Manish Rangankar <mrangankar@marvell.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 0 insertions, 15 deletions

diff --git a/drivers/scsi/qedi/qedi_fw.c b/drivers/scsi/qedi/qedi_fw.c
index cf57b4e49700..c12bb2dd5ff9 100644
--- a/drivers/scsi/qedi/qedi_fw.c
+++ b/drivers/scsi/qedi/qedi_fw.c
@@ -73,7 +73,6 @@ static void qedi_process_logout_resp(struct qedi_ctx *qedi,
 	spin_unlock(&qedi_conn->list_lock);
 
 	cmd->state = RESPONSE_RECEIVED;
-	qedi_clear_task_idx(qedi, cmd->task_id);
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)resp_hdr, NULL, 0);
 
 	spin_unlock(&session->back_lock);
@@ -138,7 +137,6 @@ static void qedi_process_text_resp(struct qedi_ctx *qedi,
 	spin_unlock(&qedi_conn->list_lock);
 
 	cmd->state = RESPONSE_RECEIVED;
-	qedi_clear_task_idx(qedi, cmd->task_id);
 
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)resp_hdr_ptr,
 			     qedi_conn->gen_pdu.resp_buf,
@@ -164,13 +162,11 @@ static void qedi_tmf_resp_work(struct work_struct *work)
 	iscsi_block_session(session->cls_session);
 	rval = qedi_cleanup_all_io(qedi, qedi_conn, qedi_cmd->task, true);
 	if (rval) {
-		qedi_clear_task_idx(qedi, qedi_cmd->task_id);
 		iscsi_unblock_session(session->cls_session);
 		goto exit_tmf_resp;
 	}
 
 	iscsi_unblock_session(session->cls_session);
-	qedi_clear_task_idx(qedi, qedi_cmd->task_id);
 
 	spin_lock(&session->back_lock);
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)resp_hdr_ptr, NULL, 0);
@@ -245,8 +241,6 @@ static void qedi_process_tmf_resp(struct qedi_ctx *qedi,
 		goto unblock_sess;
 	}
 
-	qedi_clear_task_idx(qedi, qedi_cmd->task_id);
-
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)resp_hdr_ptr, NULL, 0);
 	kfree(resp_hdr_ptr);
 
@@ -314,7 +308,6 @@ static void qedi_process_login_resp(struct qedi_ctx *qedi,
 		  "Freeing tid=0x%x for cid=0x%x\n",
 		  cmd->task_id, qedi_conn->iscsi_conn_id);
 	cmd->state = RESPONSE_RECEIVED;
-	qedi_clear_task_idx(qedi, cmd->task_id);
 }
 
 static void qedi_get_rq_bdq_buf(struct qedi_ctx *qedi,
@@ -468,7 +461,6 @@ static int qedi_process_nopin_mesg(struct qedi_ctx *qedi,
 		}
 
 		spin_unlock(&qedi_conn->list_lock);
-		qedi_clear_task_idx(qedi, cmd->task_id);
 	}
 
 done:
@@ -673,7 +665,6 @@ static void qedi_scsi_completion(struct qedi_ctx *qedi,
 	if (qedi_io_tracing)
 		qedi_trace_io(qedi, task, cmd->task_id, QEDI_IO_TRACE_RSP);
 
-	qedi_clear_task_idx(qedi, cmd->task_id);
 	__iscsi_complete_pdu(conn, (struct iscsi_hdr *)hdr,
 			     conn->data, datalen);
 error:
@@ -730,7 +721,6 @@ static void qedi_process_nopin_local_cmpl(struct qedi_ctx *qedi,
 		  cqe->itid, cmd->task_id);
 
 	cmd->state = RESPONSE_RECEIVED;
-	qedi_clear_task_idx(qedi, cmd->task_id);
 
 	spin_lock_bh(&session->back_lock);
 	__iscsi_put_task(task);
@@ -748,7 +738,6 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi,
 	itt_t protoitt = 0;
 	int found = 0;
 	struct qedi_cmd *qedi_cmd = NULL;
-	u32 rtid = 0;
 	u32 iscsi_cid;
 	struct qedi_conn *qedi_conn;
 	struct qedi_cmd *dbg_cmd;
@@ -779,7 +768,6 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi,
 			found = 1;
 			mtask = qedi_cmd->task;
 			tmf_hdr = (struct iscsi_tm *)mtask->hdr;
-			rtid = work->rtid;
 
 			list_del_init(&work->list);
 			kfree(work);
@@ -821,8 +809,6 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi,
 			if (qedi_cmd->state == CLEANUP_WAIT_FAILED)
 				qedi_cmd->state = CLEANUP_RECV;
 
-			qedi_clear_task_idx(qedi_conn->qedi, rtid);
-
 			spin_lock(&qedi_conn->list_lock);
 			if (likely(dbg_cmd->io_cmd_in_list)) {
 				dbg_cmd->io_cmd_in_list = false;
@@ -856,7 +842,6 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi,
 		QEDI_INFO(&qedi->dbg_ctx, QEDI_LOG_TID,
 			  "Freeing tid=0x%x for cid=0x%x\n",
 			  cqe->itid, qedi_conn->iscsi_conn_id);
-		qedi_clear_task_idx(qedi_conn->qedi, cqe->itid);
 
 	} else {
 		qedi_get_proto_itt(qedi, cqe->itid, &ptmp_itt);