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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEA90C433F5 for ; Mon, 6 Dec 2021 10:44:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238948AbhLFKsX (ORCPT ); Mon, 6 Dec 2021 05:48:23 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:39570 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238305AbhLFKsX (ORCPT ); Mon, 6 Dec 2021 05:48:23 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7BC1E6122C for ; Mon, 6 Dec 2021 10:44:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53132C341C2; Mon, 6 Dec 2021 10:44:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638787493; bh=8JlqtK8I7E7Ez3sVfjSwLeR2OhvR7ZnFGuHjgeRYzRc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Cv212q6gIUjJfCmzwekB8G3SOwbejjkKyLXtOu8FuPYmGZoTsMpCGZqgCrBVZ0DCP wmuGFJVMLyyZ2sFodZPyN7sIqm3rUMsLK5g62XtF5FOEVcwdrLri+x0er7Hn+QkTYQ grKhDnojHS9lkPFb6gkuzj8XdGFU+I+Vofkcbcglgb+cIsYrKneJtx+96YHxTXD0sV EF/N6q+s5mXUI0V22gUTtsOugMER8eCsdLwNh5W0/jHFAqe7PLS4gTf4Ruou61zNII cq83l+VQcvxQ6xXHOmVlLeIYRJoLQOfR0bN3sEAf5bJFqS/6Lfn/EC7TS3pXAhR5od 4FL1ljTQOKpmw== Date: Mon, 6 Dec 2021 10:44:51 +0000 From: Filipe Manana To: Josef Bacik Cc: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH v2 2/2] btrfs: reserve extra space for the free space tree Message-ID: References: <18b2ae0948a035aa809ba38641439e2d4167ca29.1638477127.git.josef@toxicpanda.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18b2ae0948a035aa809ba38641439e2d4167ca29.1638477127.git.josef@toxicpanda.com> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Dec 02, 2021 at 03:34:32PM -0500, Josef Bacik wrote: > Filipe reported a problem where sometimes he'd get an ENOSPC abort when > running delayed refs with generic/619 and the free space tree enabled. > This is partly because we do not reserve space for modifying the free > space tree, nor do we have a block rsv associated with that tree. > > The delayed_refs_rsv tracks the amount of space required to run delayed > refs. This means 1 modification means 1 change to the extent root. > With the free space tree this turns into 2 changes, because modifying 1 > extent means updating the extent tree and potentially updating the free > space tree to either remove that entry or add the free space. Thus if > we have the FST enabled, simply double the reservation size for our > modification. > > Signed-off-by: Josef Bacik > --- > fs/btrfs/block-rsv.c | 1 + > fs/btrfs/delayed-ref.c | 22 ++++++++++++++++++++++ > 2 files changed, 23 insertions(+) > > diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c > index b3086f252ad0..b3ee49b0b1e8 100644 > --- a/fs/btrfs/block-rsv.c > +++ b/fs/btrfs/block-rsv.c > @@ -426,6 +426,7 @@ void btrfs_init_root_block_rsv(struct btrfs_root *root) > switch (root->root_key.objectid) { > case BTRFS_CSUM_TREE_OBJECTID: > case BTRFS_EXTENT_TREE_OBJECTID: > + case BTRFS_FREE_SPACE_TREE_OBJECTID: > root->block_rsv = &fs_info->delayed_refs_rsv; > break; > case BTRFS_ROOT_TREE_OBJECTID: > diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c > index da9d20813147..533521be8fdf 100644 > --- a/fs/btrfs/delayed-ref.c > +++ b/fs/btrfs/delayed-ref.c > @@ -84,6 +84,17 @@ void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr) > u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr); > u64 released = 0; > > + /* > + * We have to check the mount option here because we could be enabling > + * the free space tree for the first time and don't have the compat_ro > + * option set yet. > + * > + * We need extra reservations if we have the free space tree because > + * we'll have to modify that tree as well. > + */ > + if (btrfs_test_opt(fs_info, FREE_SPACE_TREE)) > + num_bytes <<= 1; > + > released = btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL); > if (released) > trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", > @@ -108,6 +119,17 @@ void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans) > > num_bytes = btrfs_calc_insert_metadata_size(fs_info, > trans->delayed_ref_updates); > + /* > + * We have to check the mount option here because we could be enabling > + * the free space tree for the first time and don't have the compat_ro > + * option set yet. > + * > + * We need extra reservations if we have the free space tree because > + * we'll have to modify that tree as well. > + */ > + if (btrfs_test_opt(fs_info, FREE_SPACE_TREE)) > + num_bytes <<= 1; Don't we need to bump the minimum (limit variable) number of bytes at btrfs_delayed_refs_rsv_refill() as well? I don't see why not. Thanks. > + > spin_lock(&delayed_rsv->lock); > delayed_rsv->size += num_bytes; > delayed_rsv->full = 0; > -- > 2.26.3 >