From patchwork Sat Jan 11 09:49:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 234047 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47EFFC47409 for ; Sat, 11 Jan 2020 10:25:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1ED3D2087F for ; Sat, 11 Jan 2020 10:25:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578738349; bh=gFGpe93+udtJL3IRuqv7gvEvTZ38Dbi175XlBDXH+/A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sxF8zS+9EoS1cllOICo8fxgVopnY39/heiQZwZnMegGaKV83Wm8QYDNvKa4ZPGobm NB9d1tBanYv1mBlYHXEUzdNzOx49xdnllWJy200LT6Lp04OTp/h252jnivOeAS4kXn 2IPwW5dWshcB08e62szD80HZnvV7nKKI1DaoBWTc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731069AbgAKKZp (ORCPT ); Sat, 11 Jan 2020 05:25:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:57122 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729245AbgAKKZo (ORCPT ); Sat, 11 Jan 2020 05:25:44 -0500 Received: from localhost (unknown [62.119.166.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EDE0920848; Sat, 11 Jan 2020 10:25:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578738344; bh=gFGpe93+udtJL3IRuqv7gvEvTZ38Dbi175XlBDXH+/A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OmIpYRno8ymqITYFNeNOg3YFdLWIsaa16VzC6vE7+cflFpyx+8War1g2idhRtLwUz N/ow4tdib/8Z4CM9ldiO8Anddp6RGFiQNxEmwnxyUIyQQo1uyt9Mw40fxPYPhA5bSP N1cY1CrB1D03C1kSlf2IaamBkukRoCrjq9/Zr8AE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johannes Thumshirn , Josef Bacik , David Sterba , Sasha Levin Subject: [PATCH 5.4 077/165] btrfs: handle error in btrfs_cache_block_group Date: Sat, 11 Jan 2020 10:49:56 +0100 Message-Id: <20200111094927.634167726@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094921.347491861@linuxfoundation.org> References: <20200111094921.347491861@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Josef Bacik [ Upstream commit db8fe64f9ce61d1d89d3c3c34d111a43afb9f053 ] We have a BUG_ON(ret < 0) in find_free_extent from btrfs_cache_block_group. If we fail to allocate our ctl we'll just panic, which is not good. Instead just go on to another block group. If we fail to find a block group we don't want to return ENOSPC, because really we got a ENOMEM and that's the root of the problem. Save our return from btrfs_cache_block_group(), and then if we still fail to make our allocation return that ret so we get the right error back. Tested with inject-error.py from bcc. Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/extent-tree.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index eb95ed78a18e..dc50605ecbda 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3781,6 +3781,7 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, u64 flags, int delalloc) { int ret = 0; + int cache_block_group_error = 0; struct btrfs_free_cluster *last_ptr = NULL; struct btrfs_block_group_cache *block_group = NULL; struct find_free_extent_ctl ffe_ctl = {0}; @@ -3940,7 +3941,20 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, if (unlikely(!ffe_ctl.cached)) { ffe_ctl.have_caching_bg = true; ret = btrfs_cache_block_group(block_group, 0); - BUG_ON(ret < 0); + + /* + * If we get ENOMEM here or something else we want to + * try other block groups, because it may not be fatal. + * However if we can't find anything else we need to + * save our return here so that we return the actual + * error that caused problems, not ENOSPC. + */ + if (ret < 0) { + if (!cache_block_group_error) + cache_block_group_error = ret; + ret = 0; + goto loop; + } ret = 0; } @@ -4027,7 +4041,7 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, if (ret > 0) goto search; - if (ret == -ENOSPC) { + if (ret == -ENOSPC && !cache_block_group_error) { /* * Use ffe_ctl->total_free_space as fallback if we can't find * any contiguous hole. @@ -4038,6 +4052,8 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, space_info->max_extent_size = ffe_ctl.max_extent_size; spin_unlock(&space_info->lock); ins->offset = ffe_ctl.max_extent_size; + } else if (ret == -ENOSPC) { + ret = cache_block_group_error; } return ret; }