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authorJaved Hasan <jhasan@marvell.com>2020-12-15 22:47:31 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2021-01-13 07:07:32 +0300
commitb2b0f16fa65e910a3ec8771206bb49ee87a54ac5 (patch)
tree18bb6288dcd54a1f4529959814d4bc0af3d41261 /drivers/scsi/libfc/fc_exch.c
parent72eeb7c7151302ef007f1acd018cbf6f30e50321 (diff)
downloadlinux-b2b0f16fa65e910a3ec8771206bb49ee87a54ac5.tar.xz
scsi: libfc: Avoid invoking response handler twice if ep is already completed
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>
Diffstat (limited to 'drivers/scsi/libfc/fc_exch.c')
-rw-r--r--drivers/scsi/libfc/fc_exch.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index d71afae6191c..841000445b9a 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -1623,8 +1623,13 @@ 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;
+ }
}
/*
@@ -1643,6 +1648,7 @@ 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:
@@ -1899,10 +1905,16 @@ 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);
}