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 A642BC433EF for ; Tue, 16 Nov 2021 02:17:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9372B61B48 for ; Tue, 16 Nov 2021 02:17:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244275AbhKPCUT (ORCPT ); Mon, 15 Nov 2021 21:20:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:55530 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238295AbhKORmX (ORCPT ); Mon, 15 Nov 2021 12:42:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A42E36326A; Mon, 15 Nov 2021 17:27:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636997263; bh=DNoS8K/28ovLKH4tRWrtf27zKj3QB/9JE/uTxbgLdLU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Okmb8PfmJfeaeAxG12xokXgvt8xigQ5kJm1zfmSmN3O75DFa0sqY1vJRJ7Ta76v9J bzBX4u4aUL1CuAk732UsFSlIoRca14T7azIn4rzvuFH17jo2r1pM8xErQU7h9bGz6w oWyCiLT4I6a517mYC9ZxgvmLYCkcZWHzLwdpmRoY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josef Bacik , Anand Jain , David Sterba Subject: [PATCH 5.10 085/575] btrfs: call btrfs_check_rw_degradable only if there is a missing device Date: Mon, 15 Nov 2021 17:56:50 +0100 Message-Id: <20211115165346.587738360@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165343.579890274@linuxfoundation.org> References: <20211115165343.579890274@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anand Jain commit 5c78a5e7aa835c4f08a7c90fe02d19f95a776f29 upstream. In open_ctree() in btrfs_check_rw_degradable() [1], we check each block group individually if at least the minimum number of devices is available for that profile. If all the devices are available, then we don't have to check degradable. [1] open_ctree() :: 3559 if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) { Also before calling btrfs_check_rw_degradable() in open_ctee() at the line number shown below [2] we call btrfs_read_chunk_tree() and down to add_missing_dev() to record number of missing devices. [2] open_ctree() :: 3454 ret = btrfs_read_chunk_tree(fs_info); btrfs_read_chunk_tree() read_one_chunk() / read_one_dev() add_missing_dev() So, check if there is any missing device before btrfs_check_rw_degradable() in open_ctree(). Also, with this the mount command could save ~16ms.[3] in the most common case, that is no device is missing. [3] 1) * 16934.96 us | btrfs_check_rw_degradable [btrfs](); CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Josef Bacik Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/disk-io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3223,7 +3223,8 @@ int __cold open_ctree(struct super_block goto fail_sysfs; } - if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) { + if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices && + !btrfs_check_rw_degradable(fs_info, NULL)) { btrfs_warn(fs_info, "writable mount is not allowed due to too many missing devices"); goto fail_sysfs;