Commit b5f9d55b authored by Frank Pavlic's avatar Frank Pavlic Committed by Jeff Garzik
Browse files

[PATCH] s390: set online race in the lcs driver 



[patch 3/10] s390: set online race in the lcs driver.

From: Michael Holzheu <holzheu@de.ibm.com>

There is a race between lcs_stopcard() and lcs_open_device() which
can lead to the error 'lcs: Error in starting channel, rc=-16'.
lcs_open_device() is invoked when 'ifconfig up' is called due to a
hotplug event, which is caused by register_netdev(). In parallel
lcs_stopcard() is executed. Both functions are sending lcs commands.
The second invocation fails with -EBUSY (-16) as return value.
Move invocation of register_netdev() after invocation of lcs_stopcard
to avoid the race.

Signed-off-by: default avatarFrank Pavlic <pavlic@de.ibm.com>
parent 109a260b

drivers/s390/net/lcs.c

+16 −15
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
 *			  Frank Pavlic (pavlic@de.ibm.com) and

 *		 	  Martin Schwidefsky <schwidefsky@de.ibm.com>

 *

 *    $Revision: 1.97 $	 $Date: 2005/03/31 09:42:02 $

 *    $Revision: 1.98 $	 $Date: 2005/04/18 13:41:29 $

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by
@@ -59,7 +59,7 @@ 
/**

 * initialization string for output

 */

#define VERSION_LCS_C  "$Revision: 1.97 $"

#define VERSION_LCS_C  "$Revision: 1.98 $"



static char version[] __initdata = "LCS driver ("VERSION_LCS_C "/" VERSION_LCS_H ")";

static char debug_buffer[255];
@@ -1098,14 +1098,6 @@ lcs_check_multicast_support(struct lcs_card *card) 
		PRINT_ERR("Query IPAssist failed. Assuming unsupported!\n");

		return -EOPNOTSUPP;

	}

	/* Print out supported assists: IPv6 */

	PRINT_INFO("LCS device %s %s IPv6 support\n", card->dev->name,

		   (card->ip_assists_supported & LCS_IPASS_IPV6_SUPPORT) ?

		   "with" : "without");

	/* Print out supported assist: Multicast */

	PRINT_INFO("LCS device %s %s Multicast support\n", card->dev->name,

		   (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT) ?

		   "with" : "without");

	if (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT)

		return 0;

	return -EOPNOTSUPP;
@@ -2198,30 +2190,39 @@ lcs_new_device(struct ccwgroup_device *ccwgdev) 
	if (!dev)

		goto out;

	card->dev = dev;

netdev_out:

	card->dev->priv = card;

	card->dev->open = lcs_open_device;

	card->dev->stop = lcs_stop_device;

	card->dev->hard_start_xmit = lcs_start_xmit;

	card->dev->get_stats = lcs_getstats;

	SET_MODULE_OWNER(dev);

	if (lcs_register_netdev(ccwgdev) != 0)

		goto out;

	memcpy(card->dev->dev_addr, card->mac, LCS_MAC_LENGTH);

#ifdef CONFIG_IP_MULTICAST

	if (!lcs_check_multicast_support(card))

		card->dev->set_multicast_list = lcs_set_multicast_list;

#endif

	netif_stop_queue(card->dev);

netdev_out:

	lcs_set_allowed_threads(card,0xffffffff);

	if (recover_state == DEV_STATE_RECOVER) {

		lcs_set_multicast_list(card->dev);

		card->dev->flags |= IFF_UP;

		netif_wake_queue(card->dev);

		card->state = DEV_STATE_UP;

	} else

	} else {

		lcs_stopcard(card);

	}



	if (lcs_register_netdev(ccwgdev) != 0)

		goto out;



	/* Print out supported assists: IPv6 */

	PRINT_INFO("LCS device %s %s IPv6 support\n", card->dev->name,

		   (card->ip_assists_supported & LCS_IPASS_IPV6_SUPPORT) ?

		   "with" : "without");

	/* Print out supported assist: Multicast */

	PRINT_INFO("LCS device %s %s Multicast support\n", card->dev->name,

		   (card->ip_assists_supported & LCS_IPASS_MULTICAST_SUPPORT) ?

		   "with" : "without");

	return 0;

out:

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