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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 33F77C3F2D4 for ; Fri, 6 Mar 2020 06:53:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 07AB62072A for ; Fri, 6 Mar 2020 06:53:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cI9wU8hP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726124AbgCFGx3 (ORCPT ); Fri, 6 Mar 2020 01:53:29 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:33210 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725853AbgCFGx3 (ORCPT ); Fri, 6 Mar 2020 01:53:29 -0500 Received: by mail-pg1-f195.google.com with SMTP id m5so648937pgg.0; Thu, 05 Mar 2020 22:53:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=k8lKr+jkEueNL9fiDMUF+wF+sa4NlM0pOjvW8vJZPto=; b=cI9wU8hPNsjkX13N5xuTNuhILzY8O37rL4z49B2r3Sl2m+mTrOpiijZrJ+s1hZy9JF Ffh37HbRNWMdQSWID4UP9DwYCCUZvqlesBGTlCZUNcaLW+nAAXYat0ZZRPLh1vjWXOK2 EmOuLRn0bARfNXVKwuH5TT1eSKzAvkiDVhoOXYZMnXqsKrNnw08CGnaycDboR2/D2xNa V1KsrJmo+2XUu6C66+gD0PLVG4IR5WviMRkJc3cv5BaERJLRT5BW+bi1Bk07knJ5dZa5 94Co+hy/mTXKtWefGbrGYv1tk19yg/lYfDkKaY+7obsLDdCb22T/aG5LSxqOdB0nidwr 5OWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=k8lKr+jkEueNL9fiDMUF+wF+sa4NlM0pOjvW8vJZPto=; b=uj9DtviZooPPOqOPhOzO4oFG+wDHa3FnVeyzAuZ/db5yR8yfCrcwD3dkJfZBx4WdZ3 xIJ5JHy7pCsd15ngYdQinSFKutyXDZNHkp4gaGk+B6WLe/8hFEGqRXY89Yac0Cy3rldz cVDsPZzGgR9EUEcxVhnxnVkpoETzYDEivtg61nxCI3t7MhPlvVvQj+dHxI7r7Ipqr8wW xmZR27wG7gVmfPmw5+Wb9qgWguziDxgfQRLxGj5l6vDV/l0/jEykjsjH/JEIOsjhmHEq 6+dwUGB+NU1mHWHLAJ4OG4RzSSERa+10cUcv8LscRNk4wZx8YMaiLTDk2n0jXKOn2bI6 YXlg== X-Gm-Message-State: ANhLgQ2qLNEMn91nAdV36rfaIGmCimiNeod8twk1QlB+T7MwgXLvwo6c FXSEHc0Dybe3wfdyvIEQXA== X-Google-Smtp-Source: ADFU+vvgZDVNdDty/pVQK/EdyGZRM6m0eDOduutl9e91mTg0oLWSDt9J1tBnaAKE5BZ2ypVbyfltiQ== X-Received: by 2002:a63:4a19:: with SMTP id x25mr1943435pga.167.1583477607968; Thu, 05 Mar 2020 22:53:27 -0800 (PST) Received: from madhuparna-HP-Notebook.nitk.ac.in ([2402:3a80:1ee2:ecde:d483:e483:cccb:2577]) by smtp.gmail.com with ESMTPSA id x2sm32683411pge.2.2020.03.05.22.53.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Mar 2020 22:53:27 -0800 (PST) From: madhuparnabhowmik10@gmail.com To: clm@fb.com, josef@toxicpanda.com, dsterba@suse.com Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, joel@joelfernandes.org, linux-kernel-mentees@lists.linuxfoundation.org, paulmck@kernel.org, frextrite@gmail.com, linux@roeck-us.net, Madhuparna Bhowmik Subject: [PATCH] fs: btrfs: block-group.c: Fix suspicious RCU usage warning Date: Fri, 6 Mar 2020 12:22:43 +0530 Message-Id: <20200306065243.11699-1-madhuparnabhowmik10@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Madhuparna Bhowmik The space_info list is rcu protected. Hence, it should be traversed with rcu_read_lock held. Warning: [ 29.104591] ============================= [ 29.104756] WARNING: suspicious RCU usage [ 29.105046] 5.6.0-rc4-next-20200305 #1 Not tainted [ 29.105231] ----------------------------- [ 29.105401] fs/btrfs/block-group.c:2011 RCU-list traversed in non-reader section!! Reported-by: Guenter Roeck Signed-off-by: Madhuparna Bhowmik --- fs/btrfs/block-group.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index 404e050ce8ee..9cabeef66f5b 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1987,6 +1987,7 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info) btrfs_release_path(path); } + rcu_read_lock(); list_for_each_entry_rcu(space_info, &info->space_info, list) { if (!(btrfs_get_alloc_profile(info, space_info->flags) & (BTRFS_BLOCK_GROUP_RAID10 | @@ -2007,7 +2008,8 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info) list) inc_block_group_ro(cache, 1); } - + rcu_read_unlock(); + btrfs_init_global_block_rsv(info); ret = check_chunk_block_group_mappings(info); error: -- 2.17.1