On 12/3/21 1:52 AM, Manish Rangankar wrote:
> 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;
>
Reviewed-by: Lee Duncan <lduncan@xxxxxxxx>
