Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754662AbbGEKae (ORCPT ); Sun, 5 Jul 2015 06:30:34 -0400 Received: from mail-qg0-f51.google.com ([209.85.192.51]:33954 "EHLO mail-qg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752685AbbGEKaZ (ORCPT ); Sun, 5 Jul 2015 06:30:25 -0400 Date: Sat, 4 Jul 2015 11:12:00 -0400 From: Tejun Heo 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 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> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1349 Lines: 39 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/