From patchwork Mon Apr 8 08:19:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: frank.blaschka@de.ibm.com X-Patchwork-Id: 234594 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id C4A542C00BC for ; Mon, 8 Apr 2013 18:20:21 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934862Ab3DHIUM (ORCPT ); Mon, 8 Apr 2013 04:20:12 -0400 Received: from e06smtp15.uk.ibm.com ([195.75.94.111]:42484 "EHLO e06smtp15.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934845Ab3DHIUJ (ORCPT ); Mon, 8 Apr 2013 04:20:09 -0400 Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 8 Apr 2013 09:17:17 +0100 Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id B845A1B08074; Mon, 8 Apr 2013 09:20:05 +0100 (BST) Received: from d06av02.portsmouth.uk.ibm.com (d06av02.portsmouth.uk.ibm.com [9.149.37.228]) by b06cxnps4075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r388JuYo22872098; Mon, 8 Apr 2013 08:19:56 GMT Received: from d06av02.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av02.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r388K4Vl016888; Mon, 8 Apr 2013 02:20:05 -0600 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av02.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r388K3cG016870; Mon, 8 Apr 2013 02:20:04 -0600 Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 24631) id D52691224437; Mon, 8 Apr 2013 10:20:03 +0200 (CEST) Message-Id: <20130408082003.772850297@de.ibm.com> User-Agent: quilt/0.47-1 Date: Mon, 08 Apr 2013 10:19:27 +0200 From: frank.blaschka@de.ibm.com To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, Stefan Raspl Subject: [patch 2/2] qeth: fix qeth_wait_for_threads() deadlock for OSN devices References: <20130408081925.995757091@de.ibm.com> Content-Disposition: inline; filename=602-qeth-thread-deadlock.diff X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13040808-0342-0000-0000-000004A8CD66 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Stefan Raspl Any recovery thread will deadlock when calling qeth_wait_for_threads(), most notably when triggering a recovery on an OSN device. This patch will store the recovery thread's task pointer on recovery invocation and check in qeth_wait_for_threads() respectively to avoid deadlocks. Signed-off-by: Stefan Raspl Signed-off-by: Frank Blaschka Reviewed-by: Ursula Braun --- drivers/s390/net/qeth_core.h | 3 +++ drivers/s390/net/qeth_core_main.c | 19 +++++++++++++++++++ drivers/s390/net/qeth_l2_main.c | 2 ++ drivers/s390/net/qeth_l3_main.c | 2 ++ 4 files changed, 26 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -769,6 +769,7 @@ struct qeth_card { unsigned long thread_start_mask; unsigned long thread_allowed_mask; unsigned long thread_running_mask; + struct task_struct *recovery_task; spinlock_t ip_lock; struct list_head ip_list; struct list_head *ip_tbd_list; @@ -862,6 +863,8 @@ extern struct qeth_card_list_struct qeth extern struct kmem_cache *qeth_core_header_cache; extern struct qeth_dbf_info qeth_dbf[QETH_DBF_INFOS]; +void qeth_set_recovery_task(struct qeth_card *); +void qeth_clear_recovery_task(struct qeth_card *); void qeth_set_allowed_threads(struct qeth_card *, unsigned long , int); int qeth_threads_running(struct qeth_card *, unsigned long); int qeth_wait_for_threads(struct qeth_card *, unsigned long); --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -177,6 +177,23 @@ const char *qeth_get_cardname_short(stru return "n/a"; } +void qeth_set_recovery_task(struct qeth_card *card) +{ + card->recovery_task = current; +} +EXPORT_SYMBOL_GPL(qeth_set_recovery_task); + +void qeth_clear_recovery_task(struct qeth_card *card) +{ + card->recovery_task = NULL; +} +EXPORT_SYMBOL_GPL(qeth_clear_recovery_task); + +static bool qeth_is_recovery_task(const struct qeth_card *card) +{ + return card->recovery_task == current; +} + void qeth_set_allowed_threads(struct qeth_card *card, unsigned long threads, int clear_start_mask) { @@ -205,6 +222,8 @@ EXPORT_SYMBOL_GPL(qeth_threads_running); int qeth_wait_for_threads(struct qeth_card *card, unsigned long threads) { + if (qeth_is_recovery_task(card)) + return 0; return wait_event_interruptible(card->wait_q, qeth_threads_running(card, threads) == 0); } --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -1143,6 +1143,7 @@ static int qeth_l2_recover(void *ptr) QETH_CARD_TEXT(card, 2, "recover2"); dev_warn(&card->gdev->dev, "A recovery process has been started for the device\n"); + qeth_set_recovery_task(card); __qeth_l2_set_offline(card->gdev, 1); rc = __qeth_l2_set_online(card->gdev, 1); if (!rc) @@ -1153,6 +1154,7 @@ static int qeth_l2_recover(void *ptr) dev_warn(&card->gdev->dev, "The qeth device driver " "failed to recover an error on the device\n"); } + qeth_clear_recovery_task(card); qeth_clear_thread_start_bit(card, QETH_RECOVER_THREAD); qeth_clear_thread_running_bit(card, QETH_RECOVER_THREAD); return 0; --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -3515,6 +3515,7 @@ static int qeth_l3_recover(void *ptr) QETH_CARD_TEXT(card, 2, "recover2"); dev_warn(&card->gdev->dev, "A recovery process has been started for the device\n"); + qeth_set_recovery_task(card); __qeth_l3_set_offline(card->gdev, 1); rc = __qeth_l3_set_online(card->gdev, 1); if (!rc) @@ -3525,6 +3526,7 @@ static int qeth_l3_recover(void *ptr) dev_warn(&card->gdev->dev, "The qeth device driver " "failed to recover an error on the device\n"); } + qeth_clear_recovery_task(card); qeth_clear_thread_start_bit(card, QETH_RECOVER_THREAD); qeth_clear_thread_running_bit(card, QETH_RECOVER_THREAD); return 0;