From: Javed Hasan jhasan@marvell.com
[ Upstream commit b2b0f16fa65e910a3ec8771206bb49ee87a54ac5 ]
A race condition exists between the response handler getting called because of exchange_mgr_reset() (which clears out all the active XIDs) and the response we get via an interrupt.
Sequence of events:
rport ba0200: Port timeout, state PLOGI rport ba0200: Port entered PLOGI state from PLOGI state xid 1052: Exchange timer armed : 20000 msecs xid timer armed here rport ba0200: Received LOGO request while in state PLOGI rport ba0200: Delete port rport ba0200: work event 3 rport ba0200: lld callback ev 3 bnx2fc: rport_event_hdlr: event = 3, port_id = 0xba0200 bnx2fc: ba0200 - rport not created Yet!! /* Here we reset any outstanding exchanges before freeing rport using the exch_mgr_reset() */ xid 1052: Exchange timer canceled /* Here we got two responses for one xid */ xid 1052: invoking resp(), esb 20000000 state 3 xid 1052: invoking resp(), esb 20000000 state 3 xid 1052: fc_rport_plogi_resp() : ep->resp_active 2 xid 1052: fc_rport_plogi_resp() : ep->resp_active 2
Skip the response if the exchange is already completed.
Link: https://lore.kernel.org/r/20201215194731.2326-1-jhasan@marvell.com Signed-off-by: Javed Hasan jhasan@marvell.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/libfc/fc_exch.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c index 52e8666598531..e5b18e5d46dac 100644 --- a/drivers/scsi/libfc/fc_exch.c +++ b/drivers/scsi/libfc/fc_exch.c @@ -1619,8 +1619,13 @@ static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp) rc = fc_exch_done_locked(ep); WARN_ON(fc_seq_exch(sp) != ep); spin_unlock_bh(&ep->ex_lock); - if (!rc) + if (!rc) { fc_exch_delete(ep); + } else { + FC_EXCH_DBG(ep, "ep is completed already," + "hence skip calling the resp\n"); + goto skip_resp; + } }
/* @@ -1639,6 +1644,7 @@ static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp) if (!fc_invoke_resp(ep, sp, fp)) fc_frame_free(fp);
+skip_resp: fc_exch_release(ep); return; rel: @@ -1895,10 +1901,16 @@ static void fc_exch_reset(struct fc_exch *ep)
fc_exch_hold(ep);
- if (!rc) + if (!rc) { fc_exch_delete(ep); + } else { + FC_EXCH_DBG(ep, "ep is completed already," + "hence skip calling the resp\n"); + goto skip_resp; + }
fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED)); +skip_resp: fc_seq_set_resp(sp, NULL, ep->arg); fc_exch_release(ep); }