From patchwork Tue Jul 12 07:03:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12914573 X-Patchwork-Delegate: song@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73F74C433EF for ; Tue, 12 Jul 2022 07:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232327AbiGLHEF (ORCPT ); Tue, 12 Jul 2022 03:04:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232284AbiGLHDy (ORCPT ); Tue, 12 Jul 2022 03:03:54 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B349C286E5; Tue, 12 Jul 2022 00:03:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=mzCSAg5B5OmRv/K/foUA71C+W0d66BglOtnfbSo+NRk=; b=eDVmxaHUCaFvOcMvpImrykZW2x feTodMSnpeNtEYvIF/I+2vPqShEmiOw9vG5AS+UAUlS/lfODYbdGT5xBKPtqn2qJi+NBkCVxTlxa/ 3nWr8ckgVCek4UClSCsyOA0MDrmQtmFurm2N6ysCdIIcgtAFS6SFaAhO80fTgTaUFq4SJdZC5JuRM NNccxR1dk9VBbLhWaXA7AGclJi4EENCvbaf5cHQeP2DJVPu5SYCYnC8AKCshJLKYR0zKbJvLPDZ0H Bkg5fPh95RHkDzk/GMVzpNbGZRXetSdlnrdPjKyn23v4c7Ce88ys/LAtXlxukC0C7MURfzsM6FKPM hyDJj5Pw==; Received: from ip4d15c27d.dynamic.kabel-deutschland.de ([77.21.194.125] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oB9vw-008DXo-75; Tue, 12 Jul 2022 07:03:48 +0000 From: Christoph Hellwig To: Song Liu Cc: Logan Gunthorpe , linux-raid@vger.kernel.org, linux-block@vger.kernel.org Subject: [PATCH 5/8] md: stop using for_each_mddev in md_notify_reboot Date: Tue, 12 Jul 2022 09:03:28 +0200 Message-Id: <20220712070331.1390700-6-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220712070331.1390700-1-hch@lst.de> References: <20220712070331.1390700-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Just do a simple list_for_each_entry_safe on all_mddevs, and only grab a reference when we drop the lock. Reviewed-by: Christoph Hellwig --- drivers/md/md.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index d22608dcb25fe..73abeaed0b6fc 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -9547,11 +9547,13 @@ EXPORT_SYMBOL_GPL(rdev_clear_badblocks); static int md_notify_reboot(struct notifier_block *this, unsigned long code, void *x) { - struct list_head *tmp; - struct mddev *mddev; + struct mddev *mddev, *n; int need_delay = 0; - for_each_mddev(mddev, tmp) { + spin_lock(&all_mddevs_lock); + list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) { + mddev_get(mddev); + spin_unlock(&all_mddevs_lock); if (mddev_trylock(mddev)) { if (mddev->pers) __md_stop_writes(mddev); @@ -9560,7 +9562,11 @@ static int md_notify_reboot(struct notifier_block *this, mddev_unlock(mddev); } need_delay = 1; + mddev_put(mddev); + spin_lock(&all_mddevs_lock); } + spin_unlock(&all_mddevs_lock); + /* * certain more exotic SCSI devices are known to be * volatile wrt too early system reboots. While the