From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f182.google.com (mail-qk0-f182.google.com [209.85.220.182]) by kanga.kvack.org (Postfix) with ESMTP id 81E11280281 for ; Sat, 4 Jul 2015 11:12:05 -0400 (EDT) Received: by qkhu186 with SMTP id u186so90149221qkh.0 for ; Sat, 04 Jul 2015 08:12:05 -0700 (PDT) Received: from mail-qk0-x22b.google.com (mail-qk0-x22b.google.com. [2607:f8b0:400d:c09::22b]) by mx.google.com with ESMTPS id f207si14382874qhc.94.2015.07.04.08.12.04 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 04 Jul 2015 08:12:04 -0700 (PDT) Received: by qkei195 with SMTP id i195so90181757qke.3 for ; Sat, 04 Jul 2015 08:12:04 -0700 (PDT) Date: Sat, 4 Jul 2015 11:12:00 -0400 From: Tejun Heo Subject: [PATCH block/for-4.3] writeback: explain why @inode is allowed to be NULL for inode_congested() Message-ID: <20150704151200.GA13251@mtj.duckdns.org> References: <1432329245-5844-1-git-send-email-tj@kernel.org> <1432329245-5844-31-git-send-email-tj@kernel.org> <20150630152105.GP7252@quack.suse.cz> <20150702014634.GF26440@mtj.duckdns.org> <20150703121721.GJ23329@quack.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150703121721.GJ23329@quack.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com, khlebnikov@yandex-team.ru Signed-off-by: Tejun Heo Suggested-by: Jan Kara --- Hello, So, something like this. I'll resend this patch as part of a patch series once -rc1 drops. Thanks. fs/fs-writeback.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -700,7 +700,7 @@ void wbc_account_io(struct writeback_con /** * inode_congested - test whether an inode is congested - * @inode: inode to test for congestion + * @inode: inode to test for congestion (may be NULL) * @cong_bits: mask of WB_[a]sync_congested bits to test * * Tests whether @inode is congested. @cong_bits is the mask of congestion @@ -710,6 +710,9 @@ void wbc_account_io(struct writeback_con * determined by whether the cgwb (cgroup bdi_writeback) for the blkcg * associated with @inode is congested; otherwise, the root wb's congestion * state is used. + * + * @inode is allowed to be NULL as this function is often called on + * mapping->host which is NULL for the swapper space. */ int inode_congested(struct inode *inode, int cong_bits) { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org