When issued LUN reset under heavy i/o, we hit the qedi WARN_ON because of a mismatch in firmware i/o cmd cleanup request count and i/o cmd cleanup response count received. The mismatch is because of the race caused by the postfix increment of cmd_cleanup_cmpl. [qedi_clearsq:1295]:18: fatal error, need hard reset, cid=0x0 WARNING: CPU: 48 PID: 110963 at drivers/scsi/qedi/qedi_fw.c:1296 qedi_clearsq+0xa5/0xd0 [qedi] CPU: 48 PID: 110963 Comm: kworker/u130:0 Kdump: loaded Tainted: G W Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 04/15/2020 Workqueue: iscsi_conn_cleanup iscsi_cleanup_conn_work_fn [scsi_transport_iscsi] RIP: 0010:qedi_clearsq+0xa5/0xd0 [qedi] RSP: 0018:ffffac2162c7fd98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff975213c40ab8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9761bf816858 RDI: ffff9761bf816858 RBP: ffff975247018628 R08: 000000000000522c R09: 000000000000005b R10: 0000000000000000 R11: ffffac2162c7fbd8 R12: ffff97522e1b2be8 R13: 0000000000000000 R14: ffff97522e1b2800 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff9761bf800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1a34e3e1a0 CR3: 0000000108bb2000 CR4: 0000000000350ee0 Call Trace: qedi_ep_disconnect+0x533/0x550 [qedi] ? iscsi_dbg_trace+0x63/0x80 [scsi_transport_iscsi] ? _cond_resched+0x15/0x30 ? iscsi_suspend_queue+0x19/0x40 [libiscsi] iscsi_ep_disconnect+0xb0/0x130 [scsi_transport_iscsi] iscsi_cleanup_conn_work_fn+0x82/0x130 [scsi_transport_iscsi] process_one_work+0x1a7/0x360 ? create_worker+0x1a0/0x1a0 worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 kthread+0x116/0x130 ? kthread_flush_work_fn+0x10/0x10 ret_from_fork+0x22/0x40 ---[ end trace 5f1441f59082235c ]--- Signed-off-by: Manish Rangankar <mrangankar@xxxxxxxxxxx> --- v1 -> v2: - Changing cmd_cleanup_cmpl variable to atomic - In completion path instead pre-increment use atomic inc. drivers/scsi/qedi/qedi_fw.c | 37 ++++++++++++++-------------------- drivers/scsi/qedi/qedi_iscsi.c | 2 +- drivers/scsi/qedi/qedi_iscsi.h | 2 +- 3 files changed, 17 insertions(+), 24 deletions(-) diff --git a/drivers/scsi/qedi/qedi_fw.c b/drivers/scsi/qedi/qedi_fw.c index 84a4204a2cb4..5916ed7662d5 100644 --- a/drivers/scsi/qedi/qedi_fw.c +++ b/drivers/scsi/qedi/qedi_fw.c @@ -732,7 +732,6 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi, { struct qedi_work_map *work, *work_tmp; u32 proto_itt = cqe->itid; - itt_t protoitt = 0; int found = 0; struct qedi_cmd *qedi_cmd = NULL; u32 iscsi_cid; @@ -812,16 +811,12 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi, return; check_cleanup_reqs: - if (qedi_conn->cmd_cleanup_req > 0) { - QEDI_INFO(&qedi->dbg_ctx, QEDI_LOG_TID, + if (atomic_inc_return(&qedi_conn->cmd_cleanup_cmpl) == + qedi_conn->cmd_cleanup_req) { + QEDI_INFO(&qedi->dbg_ctx, QEDI_LOG_SCSI_TM, "Freeing tid=0x%x for cid=0x%x\n", cqe->itid, qedi_conn->iscsi_conn_id); - qedi_conn->cmd_cleanup_cmpl++; wake_up(&qedi_conn->wait_queue); - } else { - QEDI_ERR(&qedi->dbg_ctx, - "Delayed or untracked cleanup response, itt=0x%x, tid=0x%x, cid=0x%x\n", - protoitt, cqe->itid, qedi_conn->iscsi_conn_id); } } @@ -1163,7 +1158,7 @@ int qedi_cleanup_all_io(struct qedi_ctx *qedi, struct qedi_conn *qedi_conn, } qedi_conn->cmd_cleanup_req = 0; - qedi_conn->cmd_cleanup_cmpl = 0; + atomic_set(&qedi_conn->cmd_cleanup_cmpl, 0); QEDI_INFO(&qedi->dbg_ctx, QEDI_LOG_SCSI_TM, "active_cmd_count=%d, cid=0x%x, in_recovery=%d, lun_reset=%d\n", @@ -1215,16 +1210,15 @@ int qedi_cleanup_all_io(struct qedi_ctx *qedi, struct qedi_conn *qedi_conn, qedi_conn->iscsi_conn_id); rval = wait_event_interruptible_timeout(qedi_conn->wait_queue, - ((qedi_conn->cmd_cleanup_req == - qedi_conn->cmd_cleanup_cmpl) || - test_bit(QEDI_IN_RECOVERY, - &qedi->flags)), - 5 * HZ); + (qedi_conn->cmd_cleanup_req == + atomic_read(&qedi_conn->cmd_cleanup_cmpl)) || + test_bit(QEDI_IN_RECOVERY, &qedi->flags), + 5 * HZ); if (rval) { QEDI_INFO(&qedi->dbg_ctx, QEDI_LOG_SCSI_TM, "i/o cmd_cleanup_req=%d, equal to cmd_cleanup_cmpl=%d, cid=0x%x\n", qedi_conn->cmd_cleanup_req, - qedi_conn->cmd_cleanup_cmpl, + atomic_read(&qedi_conn->cmd_cleanup_cmpl), qedi_conn->iscsi_conn_id); return 0; @@ -1233,7 +1227,7 @@ int qedi_cleanup_all_io(struct qedi_ctx *qedi, struct qedi_conn *qedi_conn, QEDI_INFO(&qedi->dbg_ctx, QEDI_LOG_SCSI_TM, "i/o cmd_cleanup_req=%d, not equal to cmd_cleanup_cmpl=%d, cid=0x%x\n", qedi_conn->cmd_cleanup_req, - qedi_conn->cmd_cleanup_cmpl, + atomic_read(&qedi_conn->cmd_cleanup_cmpl), qedi_conn->iscsi_conn_id); iscsi_host_for_each_session(qedi->shost, @@ -1242,11 +1236,10 @@ int qedi_cleanup_all_io(struct qedi_ctx *qedi, struct qedi_conn *qedi_conn, /* Enable IOs for all other sessions except current.*/ if (!wait_event_interruptible_timeout(qedi_conn->wait_queue, - (qedi_conn->cmd_cleanup_req == - qedi_conn->cmd_cleanup_cmpl) || - test_bit(QEDI_IN_RECOVERY, - &qedi->flags), - 5 * HZ)) { + (qedi_conn->cmd_cleanup_req == + atomic_read(&qedi_conn->cmd_cleanup_cmpl)) || + test_bit(QEDI_IN_RECOVERY, &qedi->flags), + 5 * HZ)) { iscsi_host_for_each_session(qedi->shost, qedi_mark_device_available); return -1; @@ -1266,7 +1259,7 @@ void qedi_clearsq(struct qedi_ctx *qedi, struct qedi_conn *qedi_conn, qedi_ep = qedi_conn->ep; qedi_conn->cmd_cleanup_req = 0; - qedi_conn->cmd_cleanup_cmpl = 0; + atomic_set(&qedi_conn->cmd_cleanup_cmpl, 0); if (!qedi_ep) { QEDI_WARN(&qedi->dbg_ctx, diff --git a/drivers/scsi/qedi/qedi_iscsi.c b/drivers/scsi/qedi/qedi_iscsi.c index 88aa7d8b11c9..282ecb4e39bb 100644 --- a/drivers/scsi/qedi/qedi_iscsi.c +++ b/drivers/scsi/qedi/qedi_iscsi.c @@ -412,7 +412,7 @@ static int qedi_conn_bind(struct iscsi_cls_session *cls_session, qedi_conn->iscsi_conn_id = qedi_ep->iscsi_cid; qedi_conn->fw_cid = qedi_ep->fw_cid; qedi_conn->cmd_cleanup_req = 0; - qedi_conn->cmd_cleanup_cmpl = 0; + atomic_set(&qedi_conn->cmd_cleanup_cmpl, 0); if (qedi_bind_conn_to_iscsi_cid(qedi, qedi_conn)) { rc = -EINVAL; diff --git a/drivers/scsi/qedi/qedi_iscsi.h b/drivers/scsi/qedi/qedi_iscsi.h index a282860da0aa..9b9f2e44fdde 100644 --- a/drivers/scsi/qedi/qedi_iscsi.h +++ b/drivers/scsi/qedi/qedi_iscsi.h @@ -155,7 +155,7 @@ struct qedi_conn { spinlock_t list_lock; /* internal conn lock */ u32 active_cmd_count; u32 cmd_cleanup_req; - u32 cmd_cleanup_cmpl; + atomic_t cmd_cleanup_cmpl; u32 iscsi_conn_id; int itt; -- 2.18.2