2017-06-23 07:11:04

by Johannes Thumshirn

Subject: [PATCH v2] qla2xxx: Protect access to qpair members with qpair->qp_lock

In qla2xx_start_scsi_mq() and qla2xx_dif_start_scsi_mq() we grab the
qpair->qp_lock but do access members of the qpair before having the lock.
Re-order the locking sequence to have all read and write access to qpair
members under the qpair->qp_lock.

Signed-off-by: Johannes Thumshirn <[email protected]>
---
drivers/scsi/qla2xxx/qla_iocb.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)

Changes to v1:
* Use __qla2x00_marker() instead of qla2x00_marker which is fit to be called
with the qp_lock held (John)
* Don't protect qpair->online and qpair->difdix_supported as it's not
needed (Hannes)

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index 8404f17f3c6c..c64036ddd365 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -1770,6 +1770,9 @@ qla2xxx_start_scsi_mq(srb_t *sp)
struct qla_hw_data *ha = vha->hw;
struct qla_qpair *qpair = sp->qpair;

+ /* Acquire qpair specific lock */
+ spin_lock_irqsave(&qpair->qp_lock, flags);
+
/* Setup qpair pointers */
rsp = qpair->rsp;
req = qpair->req;
@@ -1779,15 +1782,14 @@ qla2xxx_start_scsi_mq(srb_t *sp)

/* Send marker if required */
if (vha->marker_needed != 0) {
- if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
- QLA_SUCCESS)
+ if (__qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
+ QLA_SUCCESS) {
+ spin_unlock_irqrestore(&qpair->qp_lock, flags);
return QLA_FUNCTION_FAILED;
+ }
vha->marker_needed = 0;
}

- /* Acquire qpair specific lock */
- spin_lock_irqsave(&qpair->qp_lock, flags);
-
/* Check for room in outstanding command list. */
handle = req->current_outstanding_cmd;
for (index = 1; index < req->num_outstanding_cmds; index++) {
@@ -1942,6 +1944,8 @@ qla2xxx_dif_start_scsi_mq(srb_t *sp)
return qla2xxx_start_scsi_mq(sp);
}

+ spin_lock_irqsave(&qpair->qp_lock, flags);
+
/* Setup qpair pointers */
rsp = qpair->rsp;
req = qpair->req;
@@ -1951,15 +1955,14 @@ qla2xxx_dif_start_scsi_mq(srb_t *sp)

/* Send marker if required */
if (vha->marker_needed != 0) {
- if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
- QLA_SUCCESS)
+ if (__qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
+ QLA_SUCCESS) {
+ spin_unlock_irqrestore(&qpair->qp_lock, flags);
return QLA_FUNCTION_FAILED;
+ }
vha->marker_needed = 0;
}

- /* Acquire ring specific lock */
- spin_lock_irqsave(&qpair->qp_lock, flags);
-
/* Check for room in outstanding command list. */
handle = req->current_outstanding_cmd;
for (index = 1; index < req->num_outstanding_cmds; index++) {
--
2.12.3

2017-06-28 01:32:27

by Martin K. Petersen

Subject: Re: [PATCH v2] qla2xxx: Protect access to qpair members with qpair->qp_lock

> In qla2xx_start_scsi_mq() and qla2xx_dif_start_scsi_mq() we grab the
> qpair->qp_lock but do access members of the qpair before having the lock.
> Re-order the locking sequence to have all read and write access to qpair
> members under the qpair->qp_lock.

Cavium folks, please review!

--
Martin K. Petersen Oracle Linux Engineering

2017-06-28 01:44:43

by Madhani, Himanshu

Subject: Re: [PATCH v2] qla2xxx: Protect access to qpair members with qpair->qp_lock

Hi Martin,

On 6/27/17, 6:32 PM, "Martin K. Petersen" <[email protected]> wrote:


> In qla2xx_start_scsi_mq() and qla2xx_dif_start_scsi_mq() we grab the
> qpair->qp_lock but do access members of the qpair before having the lock.
> Re-order the locking sequence to have all read and write access to qpair
> members under the qpair->qp_lock.

Cavium folks, please review!

I am testing it internally, will update by tomorrow.

--
Martin K. Petersen Oracle Linux Engineering

Thanks,
Himanshu

2017-06-28 16:33:38

by Madhani, Himanshu

Subject: Re: [PATCH v2] qla2xxx: Protect access to qpair members with qpair->qp_lock

> On Jun 23, 2017, at 12:10 AM, Johannes Thumshirn <[email protected]> wrote:
>
> In qla2xx_start_scsi_mq() and qla2xx_dif_start_scsi_mq() we grab the
> qpair->qp_lock but do access members of the qpair before having the lock.
> Re-order the locking sequence to have all read and write access to qpair
> members under the qpair->qp_lock.
>
> Signed-off-by: Johannes Thumshirn <[email protected]>
> ---
> drivers/scsi/qla2xxx/qla_iocb.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> Changes to v1:
> * Use __qla2x00_marker() instead of qla2x00_marker which is fit to be called
> with the qp_lock held (John)
> * Don't protect qpair->online and qpair->difdix_supported as it's not
> needed (Hannes)
>
> diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
> index 8404f17f3c6c..c64036ddd365 100644
> --- a/drivers/scsi/qla2xxx/qla_iocb.c
> +++ b/drivers/scsi/qla2xxx/qla_iocb.c
> @@ -1770,6 +1770,9 @@ qla2xxx_start_scsi_mq(srb_t *sp)
> struct qla_hw_data *ha = vha->hw;
> struct qla_qpair *qpair = sp->qpair;
>
> + /* Acquire qpair specific lock */
> + spin_lock_irqsave(&qpair->qp_lock, flags);
> +
> /* Setup qpair pointers */
> rsp = qpair->rsp;
> req = qpair->req;
> @@ -1779,15 +1782,14 @@ qla2xxx_start_scsi_mq(srb_t *sp)
>
> /* Send marker if required */
> if (vha->marker_needed != 0) {
> - if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> - QLA_SUCCESS)
> + if (__qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> + QLA_SUCCESS) {
> + spin_unlock_irqrestore(&qpair->qp_lock, flags);
> return QLA_FUNCTION_FAILED;
> + }
> vha->marker_needed = 0;
> }
>
> - /* Acquire qpair specific lock */
> - spin_lock_irqsave(&qpair->qp_lock, flags);
> -
> /* Check for room in outstanding command list. */
> handle = req->current_outstanding_cmd;
> for (index = 1; index < req->num_outstanding_cmds; index++) {
> @@ -1942,6 +1944,8 @@ qla2xxx_dif_start_scsi_mq(srb_t *sp)
> return qla2xxx_start_scsi_mq(sp);
> }
>
> + spin_lock_irqsave(&qpair->qp_lock, flags);
> +
> /* Setup qpair pointers */
> rsp = qpair->rsp;
> req = qpair->req;
> @@ -1951,15 +1955,14 @@ qla2xxx_dif_start_scsi_mq(srb_t *sp)
>
> /* Send marker if required */
> if (vha->marker_needed != 0) {
> - if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> - QLA_SUCCESS)
> + if (__qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> + QLA_SUCCESS) {
> + spin_unlock_irqrestore(&qpair->qp_lock, flags);
> return QLA_FUNCTION_FAILED;
> + }
> vha->marker_needed = 0;
> }
>
> - /* Acquire ring specific lock */
> - spin_lock_irqsave(&qpair->qp_lock, flags);
> -
> /* Check for room in outstanding command list. */
> handle = req->current_outstanding_cmd;
> for (index = 1; index < req->num_outstanding_cmds; index++) {
> --
> 2.12.3
>

Looks Good.

Acked-By: Himanshu Madhani <[email protected]>

2017-07-01 20:50:43

by Martin K. Petersen

Subject: Re: [PATCH v2] qla2xxx: Protect access to qpair members with qpair->qp_lock

Johannes,

> In qla2xx_start_scsi_mq() and qla2xx_dif_start_scsi_mq() we grab the
> qpair->qp_lock but do access members of the qpair before having the lock.
> Re-order the locking sequence to have all read and write access to qpair
> members under the qpair->qp_lock.

Applied to 4.13/scsi-queue.

--
Martin K. Petersen Oracle Linux Engineering