| Message ID | 20230506232930.195451-12-cleech@redhat.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Make iscsid-kernel communications namespace-aware | expand |
On 5/6/23 4:29 PM, Chris Leech wrote: > The namespace is gone, so there is no userspace to clean up. > Force close all the sessions. > > This should be enough for software transports, there's no implementation > of migrating physical iSCSI hosts between network namespaces currently. > > Reviewed-by: Hannes Reinecke <hare@suse.de> > Signed-off-by: Chris Leech <cleech@redhat.com> > --- > drivers/scsi/scsi_transport_iscsi.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c > index 15d28186996d..10e9414844d8 100644 > --- a/drivers/scsi/scsi_transport_iscsi.c > +++ b/drivers/scsi/scsi_transport_iscsi.c > @@ -5235,9 +5235,25 @@ static int __net_init iscsi_net_init(struct net *net) > > static void __net_exit iscsi_net_exit(struct net *net) > { > + struct iscsi_cls_session *session, *tmp; > struct iscsi_net *isn; > + unsigned long flags; > + LIST_HEAD(sessions); > > isn = net_generic(net, iscsi_net_id); > + > + spin_lock_irqsave(&isn->sesslock, flags); > + list_replace_init(&isn->sesslist, &sessions); > + spin_unlock_irqrestore(&isn->sesslock, flags); > + > + /* force session destruction, there is no userspace anymore */ > + list_for_each_entry_safe(session, tmp, &sessions, sess_list) { > + device_for_each_child(&session->dev, NULL, > + iscsi_iter_force_destroy_conn_fn); > + flush_work(&session->destroy_work); I think if this flush_work actually flushed, then we would be doing a use after free because the running work would free the session from under us. We should never have a running destroy_work and be ale to see it on the sesslist right? Maybe a WARN_ON or something else so it doesn't look like a possible bug. > + __iscsi_destroy_session(&session->destroy_work); > + } > + > netlink_kernel_release(isn->nls); > isn->nls = NULL; > }
On 5/10/23 1:09 PM, michael.christie@oracle.com wrote: > On 5/6/23 4:29 PM, Chris Leech wrote: >> The namespace is gone, so there is no userspace to clean up. >> Force close all the sessions. >> >> This should be enough for software transports, there's no implementation >> of migrating physical iSCSI hosts between network namespaces currently. >> >> Reviewed-by: Hannes Reinecke <hare@suse.de> >> Signed-off-by: Chris Leech <cleech@redhat.com> >> --- >> drivers/scsi/scsi_transport_iscsi.c | 16 ++++++++++++++++ >> 1 file changed, 16 insertions(+) >> >> diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c >> index 15d28186996d..10e9414844d8 100644 >> --- a/drivers/scsi/scsi_transport_iscsi.c >> +++ b/drivers/scsi/scsi_transport_iscsi.c >> @@ -5235,9 +5235,25 @@ static int __net_init iscsi_net_init(struct net *net) >> >> static void __net_exit iscsi_net_exit(struct net *net) >> { >> + struct iscsi_cls_session *session, *tmp; >> struct iscsi_net *isn; >> + unsigned long flags; >> + LIST_HEAD(sessions); >> >> isn = net_generic(net, iscsi_net_id); >> + >> + spin_lock_irqsave(&isn->sesslock, flags); >> + list_replace_init(&isn->sesslist, &sessions); >> + spin_unlock_irqrestore(&isn->sesslock, flags); >> + >> + /* force session destruction, there is no userspace anymore */ >> + list_for_each_entry_safe(session, tmp, &sessions, sess_list) { >> + device_for_each_child(&session->dev, NULL, >> + iscsi_iter_force_destroy_conn_fn); >> + flush_work(&session->destroy_work); > > I think if this flush_work actually flushed, then we would be doing a use > after free because the running work would free the session from under us. > > We should never have a running destroy_work and be ale to see it on the sesslist > right? Maybe a WARN_ON or something else so it doesn't look like a possible > bug. Maybe not a WARN_ON. What happens if there is running destroy_works for this namespace and we return from this function? > > >> + __iscsi_destroy_session(&session->destroy_work); >> + } >> + >> netlink_kernel_release(isn->nls); >> isn->nls = NULL; >> } >
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 15d28186996d..10e9414844d8 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -5235,9 +5235,25 @@ static int __net_init iscsi_net_init(struct net *net) static void __net_exit iscsi_net_exit(struct net *net) { + struct iscsi_cls_session *session, *tmp; struct iscsi_net *isn; + unsigned long flags; + LIST_HEAD(sessions); isn = net_generic(net, iscsi_net_id); + + spin_lock_irqsave(&isn->sesslock, flags); + list_replace_init(&isn->sesslist, &sessions); + spin_unlock_irqrestore(&isn->sesslock, flags); + + /* force session destruction, there is no userspace anymore */ + list_for_each_entry_safe(session, tmp, &sessions, sess_list) { + device_for_each_child(&session->dev, NULL, + iscsi_iter_force_destroy_conn_fn); + flush_work(&session->destroy_work); + __iscsi_destroy_session(&session->destroy_work); + } + netlink_kernel_release(isn->nls); isn->nls = NULL; }