From patchwork Fri Apr 20 23:59:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 10353875 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A45AF6019C for ; Sat, 21 Apr 2018 00:00:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9585228897 for ; Sat, 21 Apr 2018 00:00:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 89E36288D3; Sat, 21 Apr 2018 00:00:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3E20E28897 for ; Sat, 21 Apr 2018 00:00:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753150AbeDTX7q (ORCPT ); Fri, 20 Apr 2018 19:59:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:47232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752775AbeDTX7L (ORCPT ); Fri, 20 Apr 2018 19:59:11 -0400 Received: from garbanzo.do-not-panic.com (c-73-15-241-2.hsd1.ca.comcast.net [73.15.241.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A3DB2217D9; Fri, 20 Apr 2018 23:59:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A3DB2217D9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mcgrof@kernel.org From: "Luis R. Rodriguez" To: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org Cc: jack@suse.cz, bart.vanassche@wdc.com, ming.lei@redhat.com, rjw@rjwysocki.net, mguzik@redhat.com, linux-pm@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" Subject: [PATCH 2/3] fs: make thaw_super_locked() really just a helper Date: Fri, 20 Apr 2018 16:59:03 -0700 Message-Id: <20180420235904.27496-3-mcgrof@kernel.org> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20180420235904.27496-1-mcgrof@kernel.org> References: <20180420235904.27496-1-mcgrof@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP thaw_super_locked() was added via commit 08fdc8a0138a ("buffer.c: call thaw_super during emergency thaw") merged on v4.17 to help with the ability so that the caller can take charge of handling the s_umount lock, however, it has left all* of the failure handling including unlocking lock of s_umount inside thaw_super_locked(). This does not make thaw_super_locked() flexible. For instance we may later want to use it with the abilty to handle unfolding of the locks ourselves. Change thaw_super_locked() to really just be a helper, and let the callers deal with all the error handling. This commit introeuces no functional changes. Signed-off-by: Luis R. Rodriguez --- fs/super.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/fs/super.c b/fs/super.c index 9d0eb5e20a1f..82bc74a16f06 100644 --- a/fs/super.c +++ b/fs/super.c @@ -937,10 +937,15 @@ void emergency_remount(void) static void do_thaw_all_callback(struct super_block *sb) { + int error; + down_write(&sb->s_umount); if (sb->s_root && sb->s_flags & MS_BORN) { emergency_thaw_bdev(sb); - thaw_super_locked(sb); + error = thaw_super_locked(sb); + if (error) + up_write(&sb->s_umount); + deactivate_locked_super(sb); } else { up_write(&sb->s_umount); } @@ -1532,14 +1537,13 @@ int freeze_super(struct super_block *sb) } EXPORT_SYMBOL(freeze_super); +/* Caller takes the sb->s_umount rw_semaphore lock and handles active count */ static int thaw_super_locked(struct super_block *sb) { int error; - if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) { - up_write(&sb->s_umount); + if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) return -EINVAL; - } if (sb_rdonly(sb)) { sb->s_writers.frozen = SB_UNFROZEN; @@ -1554,7 +1558,6 @@ static int thaw_super_locked(struct super_block *sb) printk(KERN_ERR "VFS:Filesystem thaw failed\n"); lockdep_sb_freeze_release(sb); - up_write(&sb->s_umount); return error; } } @@ -1563,7 +1566,6 @@ static int thaw_super_locked(struct super_block *sb) sb_freeze_unlock(sb); out: wake_up(&sb->s_writers.wait_unfrozen); - deactivate_locked_super(sb); return 0; } @@ -1575,7 +1577,18 @@ static int thaw_super_locked(struct super_block *sb) */ int thaw_super(struct super_block *sb) { + int error; + down_write(&sb->s_umount); - return thaw_super_locked(sb); + error = thaw_super_locked(sb); + if (error) { + up_write(&sb->s_umount); + goto out; + } + + deactivate_locked_super(sb); + +out: + return error; } EXPORT_SYMBOL(thaw_super);