From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mgwkm04.jp.fujitsu.com ([202.219.69.171]:16249 "EHLO mgwkm04.jp.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726143AbeHXGIe (ORCPT ); Fri, 24 Aug 2018 02:08:34 -0400 Received: from g01jpfmpwkw03.exch.g01.fujitsu.local (g01jpfmpwkw03.exch.g01.fujitsu.local [10.0.193.57]) by kw-mxoi1.gw.nic.fujitsu.com (Postfix) with ESMTP id A314CAC0110 for ; Fri, 24 Aug 2018 11:35:57 +0900 (JST) Subject: [PATCH] btrfs: ctree.h: Fix suspicious rcu usage warning in btrfs_debug_in_rcu() From: Misono Tomohiro To: David Howells CC: Qu Wenruo , David Sterba , References: <22614.1535039351@warthog.procyon.org.uk> <450873e0-2a8a-d757-4c68-f24e6a0466a1@jp.fujitsu.com> Message-ID: Date: Fri, 24 Aug 2018 11:35:28 +0900 MIME-Version: 1.0 In-Reply-To: <450873e0-2a8a-d757-4c68-f24e6a0466a1@jp.fujitsu.com> Content-Type: text/plain; charset="utf-8" Sender: linux-btrfs-owner@vger.kernel.org List-ID: commit 672d599041c8 ("btrfs: Use wrapper macro for rcu string to remove duplicate code") replaces some open coded rcu string handling with macro. It turns out that btrfs_debug_in_rcu() is used for the first time and the macro lacks lock/unlock of rcu string for non debug case (i.e. when message is not printed), leading suspicious RCU usage warning when CONFIG_PROVE_RCU is on. Fix this by adding a wrapper to call lock/unlock for non debug case too. Fixes: 672d599041c8 ("btrfs: Use wrapper macro for rcu string to remove duplicate code") Reported-by: David Howells Signed-off-by: Misono Tomohiro --- fs/btrfs/ctree.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 53af9f5253f4..cc8b4ff8dcea 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3390,9 +3390,9 @@ do { \ #define btrfs_debug(fs_info, fmt, args...) \ btrfs_no_printk(fs_info, KERN_DEBUG fmt, ##args) #define btrfs_debug_in_rcu(fs_info, fmt, args...) \ - btrfs_no_printk(fs_info, KERN_DEBUG fmt, ##args) + btrfs_no_printk_in_rcu(fs_info, KERN_DEBUG fmt, ##args) #define btrfs_debug_rl_in_rcu(fs_info, fmt, args...) \ - btrfs_no_printk(fs_info, KERN_DEBUG fmt, ##args) + btrfs_no_printk_in_rcu(fs_info, KERN_DEBUG fmt, ##args) #define btrfs_debug_rl(fs_info, fmt, args...) \ btrfs_no_printk(fs_info, KERN_DEBUG fmt, ##args) #endif @@ -3404,6 +3404,13 @@ do { \ rcu_read_unlock(); \ } while (0) +#define btrfs_no_printk_in_rcu(fs_info, fmt, args...) \ +do { \ + rcu_read_lock(); \ + btrfs_no_printk(fs_info, fmt, ##args); \ + rcu_read_unlock(); \ +} while (0) + #define btrfs_printk_ratelimited(fs_info, fmt, args...) \ do { \ static DEFINE_RATELIMIT_STATE(_rs, \ -- 2.14.4