From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EEABAC77B75 for ; Mon, 8 May 2023 01:19:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IwvgBJPR2aousDWZnyIIDHVaftCO6ChVHdt+b9wVzO4=; b=uk9Lv4nLlwhyoa /4W8pvQDe3utOMc+y/Fe2cqoVO/fQ6XQYt0916So1JSP260FquiSmEvvMj56H5YhtTX4PvEi0pkBT F/nKLXiITaH9QFKxZO7eV02VFAuNPRG9M+57vlPrxvofhq9aqS1pERJUGVnV0jlZ2oN431uPQbVvY ONCD9rvKSk8wDLmccLjH4nGj7qnkZ3dkh8+vCsLXaucmx8/7xOieW3+fDGX1skvFD+vNuHzMmi7d7 IT88GbedEREUj0+M81oaqJtEmyqDIbZurGGcmD752nd2oX9zp8PIzl/yoq/BBbiFECpaxIukQMdIp DGGnL75BfHGO75B9juww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pvpXG-00Gw9i-0q; Mon, 08 May 2023 01:19:30 +0000 Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pvpXE-00Gw8O-1P; Mon, 08 May 2023 01:19:28 +0000 From: Luis Chamberlain To: hch@infradead.org, djwong@kernel.org, sandeen@sandeen.net, song@kernel.org, rafael@kernel.org, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk, jack@suse.cz, jikos@kernel.org, bvanassche@acm.org, ebiederm@xmission.com Cc: mchehab@kernel.org, keescook@chromium.org, p.raghav@samsung.com, da.gomez@samsung.com, linux-fsdevel@vger.kernel.org, kernel@tuxforce.de, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Luis Chamberlain Subject: [PATCH 1/3] ext4: replace kthread freezing with auto fs freezing Date: Sun, 7 May 2023 18:19:25 -0700 Message-Id: <20230508011927.4036707-2-mcgrof@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230508011927.4036707-1-mcgrof@kernel.org> References: <20230508011927.4036707-1-mcgrof@kernel.org> MIME-Version: 1.0 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.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 superfluous freezer calls: make coccicheck MODE=patch SPFLAGS="--in-place --no-show-diff" COCCI=./fs-freeze-cleanup.cocci M=fs/ext4 virtual patch @ 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 --- fs/ext4/super.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d39f386e9baf..1f436938d8be 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -136,7 +136,7 @@ static struct file_system_type ext2_fs_type = { .init_fs_context = ext4_init_fs_context, .parameters = ext4_param_specs, .kill_sb = kill_block_super, - .fs_flags = FS_REQUIRES_DEV, + .fs_flags = FS_REQUIRES_DEV | FS_AUTOFREEZE, }; MODULE_ALIAS_FS("ext2"); MODULE_ALIAS("ext2"); @@ -152,7 +152,7 @@ static struct file_system_type ext3_fs_type = { .init_fs_context = ext4_init_fs_context, .parameters = ext4_param_specs, .kill_sb = kill_block_super, - .fs_flags = FS_REQUIRES_DEV, + .fs_flags = FS_REQUIRES_DEV | FS_AUTOFREEZE, }; MODULE_ALIAS_FS("ext3"); MODULE_ALIAS("ext3"); @@ -3790,7 +3790,6 @@ static int ext4_lazyinit_thread(void *arg) unsigned long next_wakeup, cur; BUG_ON(NULL == eli); - set_freezable(); cont_thread: while (true) { @@ -3842,8 +3841,6 @@ static int ext4_lazyinit_thread(void *arg) } mutex_unlock(&eli->li_list_mtx); - try_to_freeze(); - cur = jiffies; if ((time_after_eq(cur, next_wakeup)) || (MAX_JIFFY_OFFSET == next_wakeup)) { @@ -7245,7 +7242,7 @@ static struct file_system_type ext4_fs_type = { .init_fs_context = ext4_init_fs_context, .parameters = ext4_param_specs, .kill_sb = kill_block_super, - .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, + .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_AUTOFREEZE, }; MODULE_ALIAS_FS("ext4"); -- 2.39.2 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec