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Subject: Re: [PATCH] qla2xxx: Do not consume srb greedily
From:   Himanshu Madhani <himanshu.madhani@oracle.com>
In-Reply-To: <20200929073802.18770-1-dwagner@suse.de>
Date:   Wed, 7 Oct 2020 08:54:36 -0500
Cc:     Nilesh Javali <njavali@marvell.com>, Arun Easi <aeasi@marvell.com>,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
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Message-Id: <B442BF5B-8082-46E3-81F4-C78B0AC6B363@oracle.com>
References: <20200929073802.18770-1-dwagner@suse.de>
To:     Daniel Wagner <dwagner@suse.de>
Precedence: bulk


> On Sep 29, 2020, at 2:38 AM, Daniel Wagner <dwagner@suse.de> wrote:
>=20
> qla2xx_process_get_sp_from_handle() will clear the slot which the
> current srb is stored. So this function has a side effect. Therefore,
> we can't use it in qla24xx_process_mbx_iocb_response() to check
> for consistency and later again in qla24xx_mbx_iocb_entry().
>=20
> Let's move the consistency check directly into
> qla24xx_mbx_iocb_entry() and avoid the double call or any open coding
> of the qla2xx_process_get_sp_from_handle() functionality.
>=20
> Fixes: 31a3271ff11b ("scsi: qla2xxx: Handle incorrect entry_type =
entries")
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
> Hi,
>=20
> Brown bag for me please. My test patch had an open coded version of
> qla2xx_process_get_sp_from_handle() which didn't consume the srb. When
> I prepared it for sending it out, I 'cleaned' it up by using
> qla2xx_process_get_sp_from_handle() twice.
>=20
> Sorry,
> Daniel
>=20
> drivers/scsi/qla2xxx/qla_isr.c | 42 =
+++++++++++++++---------------------------
> 1 file changed, 15 insertions(+), 27 deletions(-)
>=20
> diff --git a/drivers/scsi/qla2xxx/qla_isr.c =
b/drivers/scsi/qla2xxx/qla_isr.c
> index 96811354f78a..2baba87c4e0c 100644
> --- a/drivers/scsi/qla2xxx/qla_isr.c
> +++ b/drivers/scsi/qla2xxx/qla_isr.c
> @@ -1839,6 +1839,7 @@ qla24xx_mbx_iocb_entry(scsi_qla_host_t *vha, =
struct req_que *req,
>     struct mbx_24xx_entry *pkt)
> {
> 	const char func[] =3D "MBX-IOCB2";
> +	struct qla_hw_data *ha =3D vha->hw;
> 	srb_t *sp;
> 	struct srb_iocb *si;
> 	u16 sz, i;
> @@ -1848,6 +1849,18 @@ qla24xx_mbx_iocb_entry(scsi_qla_host_t *vha, =
struct req_que *req,
> 	if (!sp)
> 		return;
>=20
> +	if (sp->type =3D=3D SRB_SCSI_CMD ||
> +	    sp->type =3D=3D SRB_NVME_CMD ||
> +	    sp->type =3D=3D SRB_TM_CMD) {
> +		ql_log(ql_log_warn, vha, 0x509d,
> +			"Inconsistent event entry type %d\n", sp->type);
> +		if (IS_P3P_TYPE(ha))
> +			set_bit(FCOE_CTX_RESET_NEEDED, &vha->dpc_flags);
> +		else
> +			set_bit(ISP_ABORT_NEEDED, &vha->dpc_flags);
> +		return;
> +	}
> +
> 	si =3D &sp->u.iocb_cmd;
> 	sz =3D min(ARRAY_SIZE(pkt->mb), =
ARRAY_SIZE(sp->u.iocb_cmd.u.mbx.in_mb));
>=20
> @@ -3406,32 +3419,6 @@ void qla24xx_nvme_ls4_iocb(struct scsi_qla_host =
*vha,
> 	sp->done(sp, comp_status);
> }
>=20
> -static void qla24xx_process_mbx_iocb_response(struct scsi_qla_host =
*vha,
> -	struct rsp_que *rsp, struct sts_entry_24xx *pkt)
> -{
> -	struct qla_hw_data *ha =3D vha->hw;
> -	srb_t *sp;
> -	static const char func[] =3D "MBX-IOCB2";
> -
> -	sp =3D qla2x00_get_sp_from_handle(vha, func, rsp->req, pkt);
> -	if (!sp)
> -		return;
> -
> -	if (sp->type =3D=3D SRB_SCSI_CMD ||
> -	    sp->type =3D=3D SRB_NVME_CMD ||
> -	    sp->type =3D=3D SRB_TM_CMD) {
> -		ql_log(ql_log_warn, vha, 0x509d,
> -			"Inconsistent event entry type %d\n", sp->type);
> -		if (IS_P3P_TYPE(ha))
> -			set_bit(FCOE_CTX_RESET_NEEDED, &vha->dpc_flags);
> -		else
> -			set_bit(ISP_ABORT_NEEDED, &vha->dpc_flags);
> -		return;
> -	}
> -
> -	qla24xx_mbx_iocb_entry(vha, rsp->req, (struct mbx_24xx_entry =
*)pkt);
> -}
> -
> /**
>  * qla24xx_process_response_queue() - Process response queue entries.
>  * @vha: SCSI driver HA context
> @@ -3539,7 +3526,8 @@ void qla24xx_process_response_queue(struct =
scsi_qla_host *vha,
> 			    (struct abort_entry_24xx *)pkt);
> 			break;
> 		case MBX_IOCB_TYPE:
> -			qla24xx_process_mbx_iocb_response(vha, rsp, =
pkt);
> +			qla24xx_mbx_iocb_entry(vha, rsp->req,
> +			    (struct mbx_24xx_entry *)pkt);
> 			break;
> 		case VP_CTRL_IOCB_TYPE:
> 			qla_ctrlvp_completed(vha, rsp->req,
> --=20
> 2.16.4
>=20

Makes sense :) =20

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
--
Himanshu Madhani	 Oracle Linux Engineering