From patchwork Sat Jan 14 00:34:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 13101774 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 38B66C678D7 for ; Sat, 14 Jan 2023 00:35:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231252AbjANAfE (ORCPT ); Fri, 13 Jan 2023 19:35:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231319AbjANAe1 (ORCPT ); Fri, 13 Jan 2023 19:34:27 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25FA38B504; Fri, 13 Jan 2023 16:34:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=U3bpnd6547PaoT3tgQQ7x9+yqyo+lAhpNKGMVa67XeM=; b=w9EHUy7rgp86Q5B/90dfPTHVXG N9/FDKz3TfdC7yxmfYhnSr4SyeTHxd3rl68Ff2Y/H9j8Ew37kF5rL61ehtrpsWcLfR1m5IfdMK4jd CY7AQ+jZIu1vfaTurN+btG4MAA1u68WedJGPR24qqeseYZoSavZ7mOoOTH2XGYPokRsVV+0UN1sCm 4gR5StmaY1Am5TVrlXpmenGD9MfwEqNqjebnragMeFWnyW1H/U2OFsLdCNeUdwdlQTfIax8DUkeOa g0F+Ko0eeHHXTxub/ocrr1am9G9M2TGeNWPrzxCkTjcGwZWlycduv/p+Td200sgG+vnG1mhzmTP2L XkZ6xRMw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGUUt-004twX-OK; Sat, 14 Jan 2023 00:34:11 +0000 From: Luis Chamberlain To: hch@infradead.org, djwong@kernel.org, song@kernel.org, rafael@kernel.org, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk, jack@suse.cz, bvanassche@acm.org, ebiederm@xmission.com Cc: mchehab@kernel.org, keescook@chromium.org, p.raghav@samsung.com, linux-fsdevel@vger.kernel.org, kernel@tuxforce.de, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Luis Chamberlain Subject: [RFC v3 19/24] jbd2: replace kthread freezing with auto fs freezing Date: Fri, 13 Jan 2023 16:34:04 -0800 Message-Id: <20230114003409.1168311-20-mcgrof@kernel.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230114003409.1168311-1-mcgrof@kernel.org> References: <20230114003409.1168311-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The kernel power management now supports allowing the VFS to handle filesystem freezing freezes and thawing. Take advantage of that and remove the kthread freezing. This is needed so that we properly really stop IO in flight without races after userspace has been frozen. Without this we rely on kthread freezing and its semantics are loose and error prone. The filesystem therefore is in charge of properly dealing with quiescing of the filesystem through its callbacks if it thinks it knows better than how the VFS handles it. The following Coccinelle rule was used as to remove the now superflous freezer calls: spatch --sp-file fs-freeze-cleanup.cocci --in-place --timeout 120 --dir fs/jbd2 --jobs 12 --use-gitgrep @ remove_set_freezable @ expression time; statement S, S2; expression task, current; @@ ( - set_freezable(); | - if (try_to_freeze()) - continue; | - try_to_freeze(); | - freezable_schedule(); + schedule(); | - freezable_schedule_timeout(time); + schedule_timeout(time); | - if (freezing(task)) { S } | - if (freezing(task)) { S } - else { S2 } | - freezing(current) ) @ remove_wq_freezable @ expression WQ_E, WQ_ARG1, WQ_ARG2, WQ_ARG3, WQ_ARG4; identifier fs_wq_fn; @@ ( WQ_E = alloc_workqueue(WQ_ARG1, - WQ_ARG2 | WQ_FREEZABLE, + WQ_ARG2, ...); | WQ_E = alloc_workqueue(WQ_ARG1, - WQ_ARG2 | WQ_FREEZABLE | WQ_ARG3, + WQ_ARG2 | WQ_ARG3, ...); | WQ_E = alloc_workqueue(WQ_ARG1, - WQ_ARG2 | WQ_ARG3 | WQ_FREEZABLE, + WQ_ARG2 | WQ_ARG3, ...); | WQ_E = alloc_workqueue(WQ_ARG1, - WQ_ARG2 | WQ_ARG3 | WQ_FREEZABLE | WQ_ARG4, + WQ_ARG2 | WQ_ARG3 | WQ_ARG4, ...); | WQ_E = - WQ_ARG1 | WQ_FREEZABLE + WQ_ARG1 | WQ_E = - WQ_ARG1 | WQ_FREEZABLE | WQ_ARG3 + WQ_ARG1 | WQ_ARG3 | fs_wq_fn( - WQ_FREEZABLE | WQ_ARG2 | WQ_ARG3 + WQ_ARG2 | WQ_ARG3 ) | fs_wq_fn( - WQ_FREEZABLE | WQ_ARG2 + WQ_ARG2 ) | fs_wq_fn( - WQ_FREEZABLE + 0 ) ) @ add_auto_flag @ expression E1; identifier fs_type; @@ struct file_system_type fs_type = { .fs_flags = E1 + | FS_AUTOFREEZE , }; Generated-by: Coccinelle SmPL Signed-off-by: Luis Chamberlain Signed-off-by: Luis Chamberlain --- fs/jbd2/journal.c | 54 ++++++++++++++++++----------------------------- 1 file changed, 20 insertions(+), 34 deletions(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index e80c781731f8..99a4db5b40fc 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -169,6 +169,8 @@ static int kjournald2(void *arg) { journal_t *journal = arg; transaction_t *transaction; + DEFINE_WAIT(wait); + int should_sleep = 1; /* * Set up an interval timer which can be used to trigger a commit wakeup @@ -176,8 +178,6 @@ static int kjournald2(void *arg) */ timer_setup(&journal->j_commit_timer, commit_timeout, 0); - set_freezable(); - /* Record that the journal thread is running */ journal->j_task = current; wake_up(&journal->j_wait_done_commit); @@ -212,41 +212,27 @@ static int kjournald2(void *arg) } wake_up(&journal->j_wait_done_commit); - if (freezing(current)) { - /* - * The simpler the better. Flushing journal isn't a - * good idea, because that depends on threads that may - * be already stopped. - */ - jbd2_debug(1, "Now suspending kjournald2\n"); + /* + * We assume on resume that commits are already there, + * so we don't sleep + */ + + prepare_to_wait(&journal->j_wait_commit, &wait, + TASK_INTERRUPTIBLE); + if (journal->j_commit_sequence != journal->j_commit_request) + should_sleep = 0; + transaction = journal->j_running_transaction; + if (transaction && time_after_eq(jiffies, + transaction->t_expires)) + should_sleep = 0; + if (journal->j_flags & JBD2_UNMOUNT) + should_sleep = 0; + if (should_sleep) { write_unlock(&journal->j_state_lock); - try_to_freeze(); + schedule(); write_lock(&journal->j_state_lock); - } else { - /* - * We assume on resume that commits are already there, - * so we don't sleep - */ - DEFINE_WAIT(wait); - int should_sleep = 1; - - prepare_to_wait(&journal->j_wait_commit, &wait, - TASK_INTERRUPTIBLE); - if (journal->j_commit_sequence != journal->j_commit_request) - should_sleep = 0; - transaction = journal->j_running_transaction; - if (transaction && time_after_eq(jiffies, - transaction->t_expires)) - should_sleep = 0; - if (journal->j_flags & JBD2_UNMOUNT) - should_sleep = 0; - if (should_sleep) { - write_unlock(&journal->j_state_lock); - schedule(); - write_lock(&journal->j_state_lock); - } - finish_wait(&journal->j_wait_commit, &wait); } + finish_wait(&journal->j_wait_commit, &wait); jbd2_debug(1, "kjournald2 wakes\n");