From patchwork Fri Sep 7 14:55:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Sterba X-Patchwork-Id: 10592251 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7E999921 for ; Fri, 7 Sep 2018 14:55:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 617262B560 for ; Fri, 7 Sep 2018 14:55:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 556EA2B587; Fri, 7 Sep 2018 14:55:31 +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=ham 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 05F502B560 for ; Fri, 7 Sep 2018 14:55:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730030AbeIGTgq (ORCPT ); Fri, 7 Sep 2018 15:36:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:50586 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727856AbeIGTgq (ORCPT ); Fri, 7 Sep 2018 15:36:46 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 58B94ACBB for ; Fri, 7 Sep 2018 14:55:28 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 71E10DAD81; Fri, 7 Sep 2018 16:55:11 +0200 (CEST) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: David Sterba Subject: [PATCH 05/11] btrfs: dev-replace: avoid useless lock on error handling path Date: Fri, 7 Sep 2018 16:55:11 +0200 Message-Id: <41a1cc8519061dde7a7cbf2139f672d433a5cfbd.1536331604.git.dsterba@suse.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The exit sequence in btrfs_dev_replace_start does not allow to simply add a label to the right place so the error handling after starting transaction failure jumps there. Currently there's a lock that pairs with the unlock in the section, which is unnecessary and only raises questions. Add a variable to track the locking status and avoid the extra locking. Signed-off-by: David Sterba Reviewed-by: Omar Sandoval --- fs/btrfs/dev-replace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 8b512dddf727..0a49843b2ee6 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -400,6 +400,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, int ret; struct btrfs_device *tgt_device = NULL; struct btrfs_device *src_device = NULL; + bool need_unlock; ret = btrfs_find_device_by_devspec(fs_info, srcdevid, srcdev_name, &src_device); @@ -424,6 +425,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, return PTR_ERR(trans); } + need_unlock = true; btrfs_dev_replace_write_lock(dev_replace); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: @@ -462,6 +464,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, atomic64_set(&dev_replace->num_write_errors, 0); atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); btrfs_dev_replace_write_unlock(dev_replace); + need_unlock = false; ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); if (ret) @@ -473,7 +476,6 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); - btrfs_dev_replace_write_lock(dev_replace); goto leave; } @@ -497,7 +499,8 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, leave: dev_replace->srcdev = NULL; dev_replace->tgtdev = NULL; - btrfs_dev_replace_write_unlock(dev_replace); + if (need_unlock) + btrfs_dev_replace_write_unlock(dev_replace); btrfs_destroy_dev_replace_tgtdev(tgt_device); return ret; }