Re: [PATCH] ibmvfc: Avoid path failures during live migration

2022-11-07 Thread Martin K. Petersen
On Wed, 26 Oct 2022 13:13:56 -0500, Brian King wrote:

> This patch fixes an issue reported when performing a live
> migration when multipath is configured with a short fast
> fail timeout of 5 seconds and also to have no_path_retry
> set to fail. In this scenario, all paths would go into the
> devloss state while the ibmvfc driver went through discovery
> to log back in. On a loaded system, the discovery might
> take longer than 5 seconds, which was resulting in all paths
> being marked failed, which then resulted in a read only filesystem.
> 
> [...]

Applied to 6.1/scsi-fixes, thanks!

[1/1] ibmvfc: Avoid path failures during live migration
  https://git.kernel.org/mkp/scsi/c/62fa3ce05d5d

-- 
Martin K. Petersen  Oracle Linux Engineering


[PATCH] ibmvfc: Avoid path failures during live migration

2022-10-26 Thread Brian King
This patch fixes an issue reported when performing a live
migration when multipath is configured with a short fast
fail timeout of 5 seconds and also to have no_path_retry
set to fail. In this scenario, all paths would go into the
devloss state while the ibmvfc driver went through discovery
to log back in. On a loaded system, the discovery might
take longer than 5 seconds, which was resulting in all paths
being marked failed, which then resulted in a read only filesystem.

This patch changes the migration code in ibmvfc to
avoid deleting rports at all in this scenario, so we
avoid losing all paths.

Signed-off-by: Brian King 
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 14 +++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 00684e11976b..1a0c0b7289d2 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -708,8 +708,13 @@ static void ibmvfc_init_host(struct ibmvfc_host *vhost)
memset(vhost->async_crq.msgs.async, 0, PAGE_SIZE);
vhost->async_crq.cur = 0;
 
-   list_for_each_entry(tgt, &vhost->targets, queue)
-   ibmvfc_del_tgt(tgt);
+   list_for_each_entry(tgt, &vhost->targets, queue) {
+   if (vhost->client_migrated)
+   tgt->need_login = 1;
+   else
+   ibmvfc_del_tgt(tgt);
+   }
+
scsi_block_requests(vhost->host);
ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT);
vhost->job_step = ibmvfc_npiv_login;
@@ -3235,9 +3240,12 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, 
struct ibmvfc_host *vhost,
/* We need to re-setup the interpartition connection */
dev_info(vhost->dev, "Partition migrated, Re-enabling 
adapter\n");
vhost->client_migrated = 1;
+
+   scsi_block_requests(vhost->host);
ibmvfc_purge_requests(vhost, DID_REQUEUE);
-   ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN);
+   ibmvfc_set_host_state(vhost, IBMVFC_LINK_DOWN);
ibmvfc_set_host_action(vhost, 
IBMVFC_HOST_ACTION_REENABLE);
+   wake_up(&vhost->work_wait_q);
} else if (crq->format == IBMVFC_PARTNER_FAILED || crq->format 
== IBMVFC_PARTNER_DEREGISTER) {
dev_err(vhost->dev, "Host partner adapter deregistered 
or failed (rc=%d)\n", crq->format);
ibmvfc_purge_requests(vhost, DID_ERROR);
-- 
2.31.1