Return-Path: Received: from mx2.suse.de ([195.135.220.15]:48800 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755816AbdEKNyp (ORCPT ); Thu, 11 May 2017 09:54:45 -0400 Date: Thu, 11 May 2017 15:54:43 +0200 From: Michal Hocko To: Trond Myklebust Cc: "torvalds@linux-foundation.org" , "n.borisov.lkml@gmail.com" , "linux-kernel@vger.kernel.org" , "linux-nfs@vger.kernel.org" Subject: Re: [GIT PULL] Please pull NFS client fixes for 4.12 Message-ID: <20170511135443.GN26782@dhcp22.suse.cz> References: <1494434821.4764.1.camel@primarydata.com> <1494510068.6968.0.camel@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <1494510068.6968.0.camel@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu 11-05-17 13:41:12, Trond Myklebust wrote: > On Thu, 2017-05-11 at 10:53 +0300, Nikolay Borisov wrote: > > > > On 10.05.2017 19:47, Trond Myklebust wrote: > > > Hi Linus, > > > > > > The following changes since commit > > > 4f7d029b9bf009fbee76bb10c0c4351a1870d2f3: > > > > > > ? Linux 4.11-rc7 (2017-04-16 13:00:18 -0700) > > > > > > are available in the git repository at: > > > > > > ? git://git.linux-nfs.org/projects/trondmy/linux-nfs.git tags/nfs- > > > for-4.12-1 > > > > > > for you to fetch changes up to > > > 76b2a303384e1d6299c3a0249f0f0ce2f8f96017: > > > > > > ? pNFS/flexfiles: Always attempt to call layoutstats when flexfiles > > > is enabled (2017-05-09 16:02:57 -0400) > > > > > > ---------------------------------------------------------------- > > > NFS client updates for Linux 4.12 > > > > > > Highlights include: > > > > > > Stable bugfixes: > > > - Fix use after free in write error path > > > - Use GFP_NOIO for two allocations in writeback > > > - Fix a hang in OPEN related to server reboot > > > - Check the result of nfs4_pnfs_ds_connect > > > - Fix an rcu lock leak > > > > > > Features: > > > - Removal of the unmaintained and unused OSD pNFS layout > > > - Cleanup and removal of lots of unnecessary dprintk()s > > > - Cleanup and removal of some memory failure paths now that > > > ? GFP_NOFS is guaranteed to never fail. > > > > What guarantees that? Since if this is the case then this can result > > in > > a lot of opportunities for cleanup across the whole kernel tree. > > After > > discussing with mhocko (cc'ed) it seems that in practice everything > > below COSTLY_ORDER which are not GFP_NORETRY will never fail. But > > this > > semantic is not the same as GFP_NOFAIL. E.g. nothing guarantees that > > this will stay like that in the future? > > > > Actually, going back to the code with coffee: it's the fact we have > mempools, with direct reclaim that guarantee this. Mempools are a different story, of course. They do the their own loop on top of the underlying allocator. -- Michal Hocko SUSE Labs