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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FF6CC433EF for ; Mon, 1 Nov 2021 11:53:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80F29610CA for ; Mon, 1 Nov 2021 11:53:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232113AbhKAL4D (ORCPT ); Mon, 1 Nov 2021 07:56:03 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:50954 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231749AbhKAL4B (ORCPT ); Mon, 1 Nov 2021 07:56:01 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id BCA5A21974; Mon, 1 Nov 2021 11:53:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1635767607; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qqf80UiNXnv+73qrH91edgcPX248R174aqU41BRGqJM=; b=FR2Zd3ZXZTe61NIl9ujk9AY6cxBXrYOiXeHuQbsBF9OEhoA3Tt0BogUdVajyBm7OosujSv VORL/H/IHW2SCW3u2D0rN1qBb222wOKqRoyY4FAE59QEspt3l+zeUiVxkQ/PGTLQ9EAR1y Xer1K9eUmjzMXa2kDwlgfq7gpuIE6Js= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 851CF133FE; Mon, 1 Nov 2021 11:53:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id sMKIHTfVf2HabQAAMHmgww (envelope-from ); Mon, 01 Nov 2021 11:53:27 +0000 From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH 3/3] btrfs: allow device add if balance is paused Date: Mon, 1 Nov 2021 13:53:24 +0200 Message-Id: <20211101115324.374076-4-nborisov@suse.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211101115324.374076-1-nborisov@suse.com> References: <20211101115324.374076-1-nborisov@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Currently paused balance precludes adding a device since they are both considered exclusive ops and we can have at most 1 running at a time. This is problematic in case a filesystem encounters an ENOSPC situation while balance is running, in this case the only thing the user can do is mount the fs with "skip_balance" which pauses balance and delete some data to free up space for balance. However, it should be possible to add a new device when balance is paused. Fix this by allowing device add to proceed when balance is paused. Signed-off-by: Nikolay Borisov --- fs/btrfs/ioctl.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 05969e2f4536..8e34dceee96b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3149,13 +3149,25 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg) { struct btrfs_ioctl_vol_args *vol_args; + bool restore_op = false; int ret; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) - return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) { + if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD)) + return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; + + /* + * We can do the device add because we have a paused balanced, + * change the exclusive op type and remember we should bring + * back the paused balance + */ + fs_info->exclusive_operation = BTRFS_EXCLOP_DEV_ADD; + btrfs_exclop_start_unlock(fs_info); + restore_op = true; + } vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) { @@ -3171,7 +3183,13 @@ static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg) kfree(vol_args); out: - btrfs_exclop_finish(fs_info); + if (restore_op) { + spin_lock(&fs_info->super_lock); + fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED; + spin_unlock(&fs_info->super_lock); + } else { + btrfs_exclop_finish(fs_info); + } return ret; } -- 2.25.1