On 2/25/21 1:42 PM, Tyrel Datwyler wrote:
> A hard reset results in a complete transport disconnect such that the
> CRQ connection with the partner VIOS is broken. This has the side effect
> of also invalidating the associated sub-CRQs. The current code assumes
> that the sub-CRQs are perserved resulting in a protocol violation after
> trying to reconnect them with the VIOS. This introduces an infinite loop
> such that the VIOS forces a disconnect after each subsequent attempt to
> re-register with invalid handles.
>
> Avoid the aforementioned issue by releasing the sub-CRQs prior to CRQ
> disconnect, and driving a reinitialization of the sub-CRQs once a new
> CRQ is registered with the hypervisor.
>
> fixes: faacf8c5f1d5 ("ibmvfc: add alloc/dealloc routines for SCSI Sub-CRQ Channels")
> Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx>
> Reviewed-by: Brian King <brking@xxxxxxxxxxxxx>
> ---
> drivers/scsi/ibmvscsi/ibmvfc.c | 21 +++++++++------------
> 1 file changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index 384960036f8b..2cca55f2e464 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -158,6 +158,9 @@ static void ibmvfc_npiv_logout(struct ibmvfc_host *);
> static void ibmvfc_tgt_implicit_logout_and_del(struct ibmvfc_target *);
> static void ibmvfc_tgt_move_login(struct ibmvfc_target *);
>
> +static void ibmvfc_release_sub_crqs(struct ibmvfc_host *);
> +static void ibmvfc_init_sub_crqs(struct ibmvfc_host *);
> +
> static const char *unknown_error = "unknown error";
>
> static long h_reg_sub_crq(unsigned long unit_address, unsigned long ioba,
> @@ -926,8 +929,8 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
> unsigned long flags;
> struct vio_dev *vdev = to_vio_dev(vhost->dev);
> struct ibmvfc_queue *crq = &vhost->crq;
> - struct ibmvfc_queue *scrq;
> - int i;
> +
> + ibmvfc_release_sub_crqs(vhost);
>
> /* Close the CRQ */
> do {
> @@ -936,6 +939,8 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
> rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
> } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
>
> + ibmvfc_init_sub_crqs(vhost);
This has the same issue as patch 5 in that if fail to set up sub-crqs do_enquiry
will be set to zero, but the locked code region below will then flip it back to
one which we don't want.
-T
> +
> spin_lock_irqsave(vhost->host->host_lock, flags);
> spin_lock(vhost->crq.q_lock);
> vhost->state = IBMVFC_NO_CRQ;
> @@ -947,16 +952,6 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
> memset(crq->msgs.crq, 0, PAGE_SIZE);
> crq->cur = 0;
>
> - if (vhost->scsi_scrqs.scrqs) {
> - for (i = 0; i < nr_scsi_hw_queues; i++) {
> - scrq = &vhost->scsi_scrqs.scrqs[i];
> - spin_lock(scrq->q_lock);
> - memset(scrq->msgs.scrq, 0, PAGE_SIZE);
> - scrq->cur = 0;
> - spin_unlock(scrq->q_lock);
> - }
> - }
> -
> /* And re-open it again */
> rc = plpar_hcall_norets(H_REG_CRQ, vdev->unit_address,
> crq->msg_token, PAGE_SIZE);
> @@ -966,6 +961,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
> dev_warn(vhost->dev, "Partner adapter not ready\n");
> else if (rc != 0)
> dev_warn(vhost->dev, "Couldn't register crq (rc=%d)\n", rc);
> +
> spin_unlock(vhost->crq.q_lock);
> spin_unlock_irqrestore(vhost->host->host_lock, flags);
>
> @@ -5692,6 +5688,7 @@ static void ibmvfc_deregister_scsi_channel(struct ibmvfc_host *vhost, int index)
>
> free_irq(scrq->irq, scrq);
> irq_dispose_mapping(scrq->irq);
> + scrq->irq = 0;
>
> do {
> rc = plpar_hcall_norets(H_FREE_SUB_CRQ, vdev->unit_address,
>
