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Commit bcacfcbc authored by Julian Wiedmann's avatar Julian Wiedmann Committed by David S. Miller
Browse files

s390/qeth: fix MAC address update sequence 



When changing the MAC address on a L2 qeth device, current code first
unregisters the old address, then registers the new one.
If HW rejects the new address (or the IO fails), the device ends up with
no operable address at all.

Re-order the code flow so that the old address only gets dropped if the
new address was registered successfully. While at it, add logic to catch
some corner-cases.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a936b1ef

drivers/s390/net/qeth_l2_main.c

+31 −24
Original line number Diff line number Diff line
@@ -121,13 +121,10 @@ static int qeth_l2_send_setmac(struct qeth_card *card, __u8 *mac) 
	QETH_CARD_TEXT(card, 2, "L2Setmac");

	rc = qeth_l2_send_setdelmac(card, mac, IPA_CMD_SETVMAC);

	if (rc == 0) {

		card->info.mac_bits |= QETH_LAYER2_MAC_REGISTERED;

		ether_addr_copy(card->dev->dev_addr, mac);

		dev_info(&card->gdev->dev,

			 "MAC address %pM successfully registered on device %s\n",

			card->dev->dev_addr, card->dev->name);

			 mac, card->dev->name);

	} else {

		card->info.mac_bits &= ~QETH_LAYER2_MAC_REGISTERED;

		switch (rc) {

		case -EEXIST:

			dev_warn(&card->gdev->dev,
@@ -142,19 +139,6 @@ static int qeth_l2_send_setmac(struct qeth_card *card, __u8 *mac) 
	return rc;

}



static int qeth_l2_send_delmac(struct qeth_card *card, __u8 *mac)

{

	int rc;



	QETH_CARD_TEXT(card, 2, "L2Delmac");

	if (!(card->info.mac_bits & QETH_LAYER2_MAC_REGISTERED))

		return 0;

	rc = qeth_l2_send_setdelmac(card, mac, IPA_CMD_DELVMAC);

	if (rc == 0)

		card->info.mac_bits &= ~QETH_LAYER2_MAC_REGISTERED;

	return rc;

}



static int qeth_l2_write_mac(struct qeth_card *card, u8 *mac)

{

	enum qeth_ipa_cmds cmd = is_multicast_ether_addr_64bits(mac) ?
@@ -519,6 +503,7 @@ static int qeth_l2_set_mac_address(struct net_device *dev, void *p) 
{

	struct sockaddr *addr = p;

	struct qeth_card *card = dev->ml_priv;

	u8 old_addr[ETH_ALEN];

	int rc = 0;



	QETH_CARD_TEXT(card, 3, "setmac");
@@ -530,14 +515,35 @@ static int qeth_l2_set_mac_address(struct net_device *dev, void *p) 
		return -EOPNOTSUPP;

	}

	QETH_CARD_HEX(card, 3, addr->sa_data, ETH_ALEN);

	if (!is_valid_ether_addr(addr->sa_data))

		return -EADDRNOTAVAIL;



	if (qeth_wait_for_threads(card, QETH_RECOVER_THREAD)) {

		QETH_CARD_TEXT(card, 3, "setmcREC");

		return -ERESTARTSYS;

	}

	rc = qeth_l2_send_delmac(card, &card->dev->dev_addr[0]);

	if (!rc || (rc == -ENOENT))



	if (!qeth_card_hw_is_reachable(card)) {

		ether_addr_copy(dev->dev_addr, addr->sa_data);

		return 0;

	}



	/* don't register the same address twice */

	if (ether_addr_equal_64bits(dev->dev_addr, addr->sa_data) &&

	    (card->info.mac_bits & QETH_LAYER2_MAC_REGISTERED))

		return 0;



	/* add the new address, switch over, drop the old */

	rc = qeth_l2_send_setmac(card, addr->sa_data);

	return rc ? -EINVAL : 0;

	if (rc)

		return rc;

	ether_addr_copy(old_addr, dev->dev_addr);

	ether_addr_copy(dev->dev_addr, addr->sa_data);



	if (card->info.mac_bits & QETH_LAYER2_MAC_REGISTERED)

		qeth_l2_remove_mac(card, old_addr);

	card->info.mac_bits |= QETH_LAYER2_MAC_REGISTERED;

	return 0;

}



static void qeth_promisc_to_bridge(struct qeth_card *card)
@@ -1067,8 +1073,9 @@ static int __qeth_l2_set_online(struct ccwgroup_device *gdev, int recovery_mode) 
		goto out_remove;

	}



	if (card->info.type != QETH_CARD_TYPE_OSN)

		qeth_l2_send_setmac(card, &card->dev->dev_addr[0]);

	if (card->info.type != QETH_CARD_TYPE_OSN &&

	    !qeth_l2_send_setmac(card, card->dev->dev_addr))

		card->info.mac_bits |= QETH_LAYER2_MAC_REGISTERED;



	if (qeth_is_diagass_supported(card, QETH_DIAGS_CMD_TRAP)) {

		if (card->info.hwtrap &&