From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752386AbdK1Jf7 (ORCPT ); Tue, 28 Nov 2017 04:35:59 -0500 Received: from mx2.suse.de ([195.135.220.15]:40830 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752202AbdK1Jfx (ORCPT ); Tue, 28 Nov 2017 04:35:53 -0500 Date: Tue, 28 Nov 2017 10:35:51 +0100 From: Michal Hocko To: "Darrick J. Wong" Cc: Dave Chinner , Tetsuo Handa , hch@infradead.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] xfs: handle register_shrinker error Message-ID: <20171128093551.mjwao7afv75me6ht@dhcp22.suse.cz> References: <20171123120828.31881-1-mhocko@kernel.org> <20171123132633.GB21798@infradead.org> <20171123134128.mzxv6234hypokg4k@dhcp22.suse.cz> <201711240101.CJF18223.FJtHOLOSQFOMVF@I-love.SAKURA.ne.jp> <20171123161137.ncjqskbvdm6dgb3z@dhcp22.suse.cz> <20171123220045.GV5858@dastard> <20171124073957.3z4hjwg5exqw277h@dhcp22.suse.cz> <20171127174453.GC19379@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171127174453.GC19379@magnolia> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 27-11-17 09:44:53, Darrick J. Wong wrote: [...] > > From 1009db61988c48c9a9e327a9d076945b29b02eee Mon Sep 17 00:00:00 2001 > > From: Michal Hocko > > Date: Thu, 23 Nov 2017 17:13:40 +0100 > > Subject: [PATCH] xfs: fortify xfs_alloc_buftarg error handling > > > > percpu_counter_init failure path doesn't clean up &btp->bt_lru list. > > Call list_lru_destroy in that error path. Similarly register_shrinker > > error path is not handled. > > > > While it is unlikely to trigger these error path, it is not impossible > > especially the later might fail with large NUMAs. Let's handle the > > failure to make the code more robust. > > > > Acked-by: Dave Chinner > > Noticed-by: Tetsuo Handa > > Signed-off-by: Michal Hocko > > --- > > fs/xfs/xfs_buf.c | 15 ++++++++++----- > > 1 file changed, 10 insertions(+), 5 deletions(-) > > > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > > index 4db6e8d780f6..4c6e86d861fd 100644 > > --- a/fs/xfs/xfs_buf.c > > +++ b/fs/xfs/xfs_buf.c > > @@ -1815,22 +1815,27 @@ xfs_alloc_buftarg( > > btp->bt_daxdev = dax_dev; > > > > if (xfs_setsize_buftarg_early(btp, bdev)) > > - goto error; > > + goto error_free; > > > > if (list_lru_init(&btp->bt_lru)) > > - goto error; > > + goto error_free; > > > > if (percpu_counter_init(&btp->bt_io_count, 0, GFP_KERNEL)) > > - goto error; > > + goto error_lru; > > > > btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count; > > btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan; > > btp->bt_shrinker.seeks = DEFAULT_SEEKS; > > btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE; > > - register_shrinker(&btp->bt_shrinker); > > + if (register_shrinker(&btp->bt_shrinker)) > > + goto error_pcpu; > > return btp; > > > > -error: > > +error_pcpu: > > + percpu_counter_destroy(&btp->bt_io_count); > > +error_lru: > > + list_lru_destroy(&btp->bt_lru); > > +error_free: > > kmem_free(btp); > > return NULL; > > This part looks ok, > Reviewed-by: Darrick J. Wong Are you going to apply the patch or should I re-send it with acks/reviewed-by? -- Michal Hocko SUSE Labs