Currently all port deletion is routed though the FCoE
workqueue (fcoe_wq). When fc_remove_host is called on
an N_Port (for example, from fcoe_destroy) the vports
are queued into a FC Transport workqueue. fc_remove_host
flushes that queue and each vport is passed to fcoe's
fcoe_vport_destroy, which simply queues the associated
fcoe_ports for later deletion. This queue cannot be
flushed within the N_Ports destroy path because of
circular locking issues. The result is that the NPIV
ports are destroyed after the N_Port, which is reverse
of how they are created.
This quirk causes fcoe to keep references on the
fcoe_interface shared by each of these ports (N_Port
and NPIV). This in itself is goofy, but isn't a problem
until new APIs are added to allow LLDs to create a
FC Port device. fcoe wants to allocate the fcoe_interface
as driver data of the FC Transport's FC Port. The odd
ordering creates locking problems between the Scsi_Host
mutex and the fcoe_config_mutex when destroying the
FC Port and freeing this LLD shared object.
This patch simply allows fcoe_vport_destory to destroy
NPIV ports without deferring them to a workqueue context.
This ensures that when fc_remove_host is called the
NPIV ports will be destroyed first before the N_Port and
allows reference counting on the fcoe's fcoe_interface
to be remove in a later patch.
Signed-off-by: Robert Love <robert.w.love@xxxxxxxxx>
---
drivers/scsi/fcoe/fcoe.c | 15 ++++++---------
1 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 781fbaa..0f621d3 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -1943,20 +1943,14 @@ static void fcoe_destroy_work(struct work_struct *work)
{
struct fcoe_port *port;
struct fcoe_interface *fcoe;
- int npiv = 0;
port = container_of(work, struct fcoe_port, destroy_work);
mutex_lock(&fcoe_config_mutex);
- /* set if this is an NPIV port */
- npiv = port->lport->vport ? 1 : 0;
-
fcoe = port->priv;
fcoe_if_destroy(port->lport);
- /* Do not tear down the fcoe interface for NPIV port */
- if (!npiv)
- fcoe_interface_cleanup(fcoe);
+ fcoe_interface_cleanup(fcoe);
mutex_unlock(&fcoe_config_mutex);
}
@@ -2485,12 +2479,15 @@ static int fcoe_vport_destroy(struct fc_vport *vport)
struct Scsi_Host *shost = vport_to_shost(vport);
struct fc_lport *n_port = shost_priv(shost);
struct fc_lport *vn_port = vport->dd_data;
- struct fcoe_port *port = lport_priv(vn_port);
mutex_lock(&n_port->lp_mutex);
list_del(&vn_port->list);
mutex_unlock(&n_port->lp_mutex);
- queue_work(fcoe_wq, &port->destroy_work);
+
+ mutex_lock(&fcoe_config_mutex);
+ fcoe_if_destroy(vn_port);
+ mutex_unlock(&fcoe_config_mutex);
+
return 0;
}
--
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