[SCSI] zfcp: fix deadlock caused by shared work queue tasks

Each adapter reopen trigger automatically a scan_port task which
is waiting for the ERP to be finished before further processing.
Since the initial device setup enqueues adapter, port and LUN which
are individual ERP actions, this process would start after
everything is done. Unfortunately the port_reopen requires another
scheduled work to be finished which is queued after the automatic
scan_port -> deadlock !

This fix creates an own work queue for ERP based nameserver requests.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index b9984648aca6..05f3de64f6a3 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -168,6 +168,8 @@ static int __init zfcp_module_init(void)
         if (!zfcp_data.gid_pn_cache)
                 goto out_gid_cache;
 
+        zfcp_data.work_queue = create_singlethread_workqueue("zfcp_wq");
+
         INIT_LIST_HEAD(&zfcp_data.adapter_list_head);
         sema_init(&zfcp_data.config_sema, 1);
         rwlock_init(&zfcp_data.config_lock);