From 65080c51fde468465e3547d72e4a593b1361c0f4 Mon Sep 17 00:00:00 2001 From: Dmitry Bogdanov Date: Tue, 7 Jun 2022 16:19:53 +0300 Subject: [PATCH] scsi: iscsi: Prefer xmit of DataOut over new commands iscsi_data_xmit() (TX worker) is iterating over the queue of new SCSI commands concurrently with the queue being replenished. Only after the queue is emptied will we start sending pending DataOut PDUs. That leads to DataOut timeout on the target side and to connection reinstatement. Give priority to pending DataOut commands over new commands. Link: https://lore.kernel.org/r/20220607131953.11584-1-d.bogdanov@yadro.com Reviewed-by: Konstantin Shelekhin Reviewed-by: Mike Christie Signed-off-by: Dmitry Bogdanov Signed-off-by: Martin K. Petersen --- drivers/scsi/libiscsi.c | 44 ++++++++++++++++++++++------------------- 1 file changed, 24 insertions(+), 20 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 797abf4f53995..8d78559ae94a2 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -1567,6 +1567,28 @@ check_mgmt: goto done; } +check_requeue: + while (!list_empty(&conn->requeue)) { + /* + * we always do fastlogout - conn stop code will clean up. + */ + if (conn->session->state == ISCSI_STATE_LOGGING_OUT) + break; + + task = list_entry(conn->requeue.next, struct iscsi_task, + running); + + if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT)) + break; + + list_del_init(&task->running); + rc = iscsi_xmit_task(conn, task, true); + if (rc) + goto done; + if (!list_empty(&conn->mgmtqueue)) + goto check_mgmt; + } + /* process pending command queue */ while (!list_empty(&conn->cmdqueue)) { task = list_entry(conn->cmdqueue.next, struct iscsi_task, @@ -1594,28 +1616,10 @@ check_mgmt: */ if (!list_empty(&conn->mgmtqueue)) goto check_mgmt; + if (!list_empty(&conn->requeue)) + goto check_requeue; } - while (!list_empty(&conn->requeue)) { - /* - * we always do fastlogout - conn stop code will clean up. - */ - if (conn->session->state == ISCSI_STATE_LOGGING_OUT) - break; - - task = list_entry(conn->requeue.next, struct iscsi_task, - running); - - if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT)) - break; - - list_del_init(&task->running); - rc = iscsi_xmit_task(conn, task, true); - if (rc) - goto done; - if (!list_empty(&conn->mgmtqueue)) - goto check_mgmt; - } spin_unlock_bh(&conn->session->frwd_lock); return -ENODATA; -- 2.30.2