We dropped rtnl_lock to in fcoe_update_src_mac() to avoid the deadlock of rtnl
mutex with fip controller lock in commit 949e71f. However, calling
dev_uc_add/del() must hold rtnl_lock otherwise it could hit rtnl lock assertion
failure. Since we have to follow the order of grabbing fip lock after rtnl lock
since netdev event callback comes in w/ rtnl lock held, when update_mac() is
called in libfcoe, we should drop fip lock first otherwise it will again get
back to the deadlock situation. This issue is observed in VN2VN setup.
I don't like unlock/lock there, but we need the newly mac to be added before
sending the claim otherwise there is a race that the response frame may come
back before the mac is added to the underlying device's filter table so the
frame may get dropped.
Signed-off-by: Yi Zou <yi....@intel.com>
---
drivers/scsi/fcoe/fcoe.c | 2 ++
drivers/scsi/fcoe/fcoe_ctlr.c | 2 ++
2 files changed, 4 insertions(+)
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 666b7ac..02de3c9 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -563,11 +563,13 @@ static void fcoe_update_src_mac(struct fc_lport *lport,
u8 *addr)
struct fcoe_port *port = lport_priv(lport);
struct fcoe_interface *fcoe = port->priv;
+ rtnl_lock();
if (!is_zero_ether_addr(port->data_src_addr))
dev_uc_del(fcoe->netdev, port->data_src_addr);
if (!is_zero_ether_addr(addr))
dev_uc_add(fcoe->netdev, addr);
memcpy(port->data_src_addr, addr, ETH_ALEN);
+ rtnl_unlock();
}
/**
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index 2ebe03a..485a1e7 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -2760,7 +2760,9 @@ static void fcoe_ctlr_vn_timeout(struct fcoe_ctlr *fip)
hton24(mac, FIP_VN_FC_MAP);
hton24(mac + 3, new_port_id);
fcoe_ctlr_map_dest(fip);
+ mutex_unlock(&fip->ctlr_mutex);
fip->update_mac(fip->lp, mac);
+ mutex_lock(&fip->ctlr_mutex);
fcoe_ctlr_vn_send_claim(fip);
next_time = jiffies + msecs_to_jiffies(FIP_VN_ANN_WAIT);
break;
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