[PATCH 09/22] libfc: in fc_lport_destroy, flush rports after turning off link

Robert Love
2009-07-30T00:04:33Z

From: Joe Eykholt <jeykholt@cisco.com>

During an fcoe module unload, we saw a problem where fc_rport_work()
finds the lport has been freed. The rdata points to an area
containing 0x6b6b6b6b... the pool poison value from kmem_free().

In fcoe_if_destroy() we call fc_fabric_logoff() then fc_lport_destroy().
fc_fabric_logoff() flushes the remote port work, but we're still receiving
requests, and an RSCN or PLOGI arrives which creates more rports.

Note that although the LLD also checks link_up, it doesn't do it
under the lport mutex, so it can deliver frames to
fc_lport_recv_req() even after link_up is cleared.
So, re-check link_up there.

We need to flush the rports by calling disc_stop_final()
after we clear link_up.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
---

drivers/scsi/libfc/fc_lport.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index 7bb451a..a430335 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -643,6 +643,7 @@ int fc_lport_destroy(struct fc_lport *lport)
mutex_unlock(&lport->lp_mutex);

lport->tt.fcp_abort_io(lport);
+ lport->tt.disc_stop_final(lport);
lport->tt.exch_mgr_reset(lport, 0, 0);
return 0;
}
@@ -844,7 +845,10 @@ static void fc_lport_recv_req(struct fc_lport *lport, struct fc_seq *sp,
* RSCN here. These don't require a session.
* Even if we had a session, it might not be ready.
*/
- if (fh->fh_type == FC_TYPE_ELS && fh->fh_r_ctl == FC_RCTL_ELS_REQ) {
+ if (!lport->link_up)
+ fc_frame_free(fp);
+ else if (fh->fh_type == FC_TYPE_ELS &&
+ fh->fh_r_ctl == FC_RCTL_ELS_REQ) {
/*
* Check opcode.
*/