Commit 5cf52964 authored by Tyrel Datwyler's avatar Tyrel Datwyler Committed by Martin K. Petersen
Browse files

scsi: ibmvfc: Fix invalid sub-CRQ handles after hard reset 

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.

Link: https://lore.kernel.org/r/20210302230543.9905-3-tyreld@linux.ibm.com


Fixes: 3034ebe2 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Reviewed-by: default avatarBrian King <brking@linux.ibm.com>
Signed-off-by: default avatarTyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 443cc4b4

drivers/scsi/ibmvscsi/ibmvfc.c

+9 −12
Original line number Diff line number Diff line
@@ -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 {
@@ -947,16 +950,6 @@ 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);
@@ -966,9 +959,12 @@ 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);



	ibmvfc_init_sub_crqs(vhost);



	return rc;

}
@@ -5694,6 +5690,7 @@ 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,