From f7d6790884bc9bf6089cbacaa16709f267f1fb91 Mon Sep 17 00:00:00 2001 From: Edward Tomasz Napierala Date: Wed, 18 Jun 2014 17:13:18 +0000 Subject: [PATCH] Rework session termination in iSCSI target to actually wait for any outstanding commands to be properly aborted by CTL. Without it, in some cases (such as files backing the LUNs stored on failing disk drives), terminating a busy session would result in panic. Reviewed by: mav@ (earlier version) Sponsored by: The FreeBSD Foundation --- sys/cam/ctl/ctl_frontend_iscsi.c | 38 +++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 8 deletions(-) diff --git a/sys/cam/ctl/ctl_frontend_iscsi.c b/sys/cam/ctl/ctl_frontend_iscsi.c index 2b1b9bd255a..66eb2c6043a 100644 --- a/sys/cam/ctl/ctl_frontend_iscsi.c +++ b/sys/cam/ctl/ctl_frontend_iscsi.c @@ -1045,7 +1045,7 @@ cfiscsi_session_terminate_tasks(struct cfiscsi_session *cs) { struct cfiscsi_data_wait *cdw, *tmpcdw; union ctl_io *io; - int error; + int error, last; #ifdef notyet io = ctl_alloc_io(cs->cs_target->ct_softc->fe.ctl_pool_ref); @@ -1102,12 +1102,31 @@ cfiscsi_session_terminate_tasks(struct cfiscsi_session *cs) CFISCSI_SESSION_DEBUG(cs, "removing csw for initiator task tag " "0x%x", cdw->cdw_initiator_task_tag); #endif + /* + * Set nonzero port status; this prevents backends from + * assuming that the data transfer actually succeeded + * and writing uninitialized data to disk. + */ + cdw->cdw_ctl_io->scsiio.io_hdr.port_status = 42; cdw->cdw_ctl_io->scsiio.be_move_done(cdw->cdw_ctl_io); TAILQ_REMOVE(&cs->cs_waiting_for_data_out, cdw, cdw_next); uma_zfree(cfiscsi_data_wait_zone, cdw); } CFISCSI_SESSION_UNLOCK(cs); #endif + + /* + * Wait for CTL to terminate all the tasks. + */ + for (;;) { + refcount_acquire(&cs->cs_outstanding_ctl_pdus); + last = refcount_release(&cs->cs_outstanding_ctl_pdus); + if (last != 0) + break; + CFISCSI_SESSION_WARN(cs, "waiting for CTL to terminate tasks, " + "%d remaining", cs->cs_outstanding_ctl_pdus); + pause("cfiscsi_terminate", 1); + } } static void @@ -1124,19 +1143,22 @@ cfiscsi_maintenance_thread(void *arg) CFISCSI_SESSION_UNLOCK(cs); if (cs->cs_terminating) { - cfiscsi_session_terminate_tasks(cs); - callout_drain(&cs->cs_callout); + /* + * We used to wait up to 30 seconds to deliver queued + * PDUs to the initiator. We also tried hard to deliver + * SCSI Responses for the aborted PDUs. We don't do + * that anymore. We might need to revisit that. + */ + callout_drain(&cs->cs_callout); icl_conn_shutdown(cs->cs_conn); icl_conn_close(cs->cs_conn); /* - * XXX: We used to wait up to 30 seconds to deliver queued PDUs - * to the initiator. We also tried hard to deliver SCSI Responses - * for the aborted PDUs. We don't do that anymore. We might need - * to revisit that. + * At this point ICL receive thread is no longer + * running; no new tasks can be queued. */ - + cfiscsi_session_terminate_tasks(cs); cfiscsi_session_delete(cs); kthread_exit(); return;