Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757463AbaBUAvr (ORCPT ); Thu, 20 Feb 2014 19:51:47 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45520 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755175AbaBTXv2 (ORCPT ); Thu, 20 Feb 2014 18:51:28 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe Subject: [PATCH 3.10 52/66] block: add cond_resched() to potentially long running ioctl discard loop Date: Thu, 20 Feb 2014 15:51:51 -0800 Message-Id: <20140220234910.973971325@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140220234909.482516304@linuxfoundation.org> References: <20140220234909.482516304@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jens Axboe commit c8123f8c9cb517403b51aa41c3c46ff5e10b2c17 upstream. When mkfs issues a full device discard and the device only supports discards of a smallish size, we can loop in blkdev_issue_discard() for a long time. If preempt isn't enabled, this can turn into a softlock situation and the kernel will start complaining. Add an explicit cond_resched() at the end of the loop to avoid that. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/blk-lib.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -121,6 +121,14 @@ int blkdev_issue_discard(struct block_de atomic_inc(&bb.done); submit_bio(type, bio); + + /* + * We can loop for a long time in here, if someone does + * full device discards (like mkfs). Be nice and allow + * us to schedule out to avoid softlocking if preempt + * is disabled. + */ + cond_resched(); } blk_finish_plug(&plug); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/