Return-Path: Received: from mx2.suse.de ([195.135.220.15]:57083 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754710AbcCRGF1 (ORCPT ); Fri, 18 Mar 2016 02:05:27 -0400 From: NeilBrown To: William Dauchy , "J. Bruce Fields" Date: Fri, 18 Mar 2016 17:05:18 +1100 Cc: Linux NFS mailing list Subject: Re: [PATCH] sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race In-Reply-To: References: <87y49ylq76.fsf@notabene.neil.brown.name> <20160314203846.GA22276@fieldses.org> <20160315131959.GA419@fieldses.org> <87vb4nh406.fsf@notabene.neil.brown.name> <20160316150510.GE11520@fieldses.org> Message-ID: <87wpp0e2xt.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-nfs-owner@vger.kernel.org List-ID: --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, Mar 17 2016, William Dauchy wrote: > Hi Bruce, > > Thank your for your reply. > > On Wed, Mar 16, 2016 at 4:05 PM, J. Bruce Fields w= rote: >> Why is that? > > It's indeed not really based on actual proof but based on the experience = we had. > Faced several bugs, and it appears we had less issues by backporting a > few commits; e.g related to races, leaks, performances regressions. We > did not spent enough time on it to actually show this commit was > actually fixing an issue hit. > >> Do you have a list? > > I am currently trying to switch from v3.14 to v4.1 (nfs client). So > even know it is off topic, those I have in mind: > 0d2a970 SUNRPC: Fix a backchannel race > 6851447 SUNRPC: Fix a backchannel deadlock > 0993920 SUNRPC: Prevent SYN+SYNACK+RST storms > 03c78827 SUNRPC: Fix races between socket connection and destroy code > a41cbe8 Failing to send a CLOSE if file is opened WRONLY and server > reboots on a 4.x mount > 39d0d3b NFS: Fix a tracepoint NULL-pointer dereference > 5e99b53 nfs4: reset states to use open_stateid when returning > delegation voluntarily > e92c1e0 NFSv4: Fix a nograce recovery hang > 6b55970 nfs: Fix a memory leak when meeting an unsupported state protect Commit: 7632e465feb1 ("dcache: use IS_ROOT to decide where dentry is hashed= ") is my most recent complaint - it really should have been tagged for =2Dstable. It is now in 3.12-stable, over 2 years later :-( NeilBrown > > I am probably wrong on most of them but we had better stability after > applying them and I probably forgot some. > >> I don't expect *proof*, necessarily, but some sort of argument would be >> helpful. > > In my environment, if I hit this race, it is not acceptable to not > being able to unmount the filesystem. > > Thanks, > --=20 > William --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJW65qeAAoJEDnsnt1WYoG5rfoQAMQMj1uspYRZYbfUpV4kpRnK eji9ne8jTvooNBk2pnEuBuLYr57qHHXm1WrB9wwCVVfuEM0vnJ2YzvbWBwbk2gT2 r+6z4nItkNpk9meLy4kfWYeaoaBDvgzrVpipYBXLaIolzwGAEzSOfyZy8/til/Dw YnfiUoYTEazNz9vx98XMGb+0MLu7IHyAI2ZlVPj21wsZfn4VFl8UQzRzx57xKdLQ 0tRLi8R2qHKjD82Wq7zLgywnzvG7vFVnBmPMxa+1FTTFPLWu8uYIwY/ktQ4Z1QIl 75V4fy0FGeDB2IQpdXCi7v11tImnIKiqEac7VGdQcJLvqR5OqnMi31yHDHP3/ydB L7+4eZjq5Lba5iLnixwzrSBOzpJ29qzE3NLmkm/T2D83s+6r/kM5L/hbxGm3aucg 2ls/0UBX0ylxpA2ZejncoEM2XXChI8bEgdDkFRaBZ9U8TWiC3d05YyEiiu5zkeUT kUJzv6402YHq/rHpwWzdfVqVQkIJSv/agIV7MqY7TLBaanWtS8b+IZpFL/fwIxPa mSgZgnFWgnn+A4gRKrqJHGkJVb7MkUM75P/qoxg0QMPBYkuQ9NJbDbGFOynb4jgV PqwebZBj6Zo6kOKrEJeN82rmxJjrDmzS4B4emmG/T2e/8C9FE3uI3MRxPb7d/djJ YoGbymO7I3Dl1U6SBiri =c4IC -----END PGP SIGNATURE----- --=-=-=--