Return-Path: Received: from mx2.suse.de ([195.135.220.15]:48687 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751975AbdLSUaP (ORCPT ); Tue, 19 Dec 2017 15:30:15 -0500 From: NeilBrown To: "Michael Kerrisk \(man-pages\)" Date: Wed, 20 Dec 2017 07:30:06 +1100 Cc: mtk.manpages@gmail.com, linux-man@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] fcntl.2, read.2, write.2: document "Lost locks" as cause for EIO. In-Reply-To: <130530e8-83bc-35d3-b84c-9bee85ddee12@gmail.com> References: <87lgi7nttp.fsf@notabene.neil.brown.name> <87shc7lnfs.fsf@notabene.neil.brown.name> <130530e8-83bc-35d3-b84c-9bee85ddee12@gmail.com> Message-ID: <87h8smlaup.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 Tue, Dec 19 2017, Michael Kerrisk (man-pages) wrote: > On 12/18/2017 10:45 PM, NeilBrown wrote: >> On Mon, Dec 18 2017, Michael Kerrisk (man-pages) wrote: >>=20 >>> Hello Neil >>> >>> There's a piece of your patch I don't understand. Please see below. >>> >>> On 12/13/2017 05:19 AM, NeilBrown wrote: >>>> >>>> If an advisory lock is lost, then read/write requests on any >>>> affected file descriptor can return EIO - for NFSv4 at least. >>>> >>>> Signed-off-by: NeilBrown >>>> --- >>>> man2/fcntl.2 | 24 ++++++++++++++++++++++++ >>>> man2/read.2 | 9 +++++++++ >>>> man2/write.2 | 9 +++++++++ >>>> 3 files changed, 42 insertions(+) >>>> >>>> diff --git a/man2/fcntl.2 b/man2/fcntl.2 >>>> index 67642384154c..6e6e26f66aa0 100644 >>>> --- a/man2/fcntl.2 >>>> +++ b/man2/fcntl.2 >>>> @@ -669,6 +669,30 @@ and >>>> Mandatory locking is not specified by POSIX. >>>> Some other systems also support mandatory locking, >>>> although the details of how to enable it vary across systems. >>>> +.SS Lost locks >>>> +When an advisory lock is obtained on a networked filesystem such as >>>> +NFS it is possible that the lock might get lost. >>>> +This may happen due to administrative action on the server, or due to= a >>>> +network partition which lasts long enough for the server to assume >>> >>> What does "network partition which lasts long enough" mean? >>> I think this perhaps needs to be clarified a little. At least, >>> I don't understand it. >>=20 >> "network partition" is a term using the NFS RFCs for any situation that >> that results in the server and client not being able to communicate >> (that are partitioned, one from the other? There is partition (wall) >> between them? They are in separate partitions?). >> I can see how the meaning might not be obvious if you hadn't come across >> it before. >>=20 >> If we change "network partition" to "loss of connectivity", would that >> make it clear. Is "loss of network connectivity with the server" too >> verbose? > > Thanks, Neil. I've applied your patch and added the words "loss of network > connectivity with the server". Looks good. Thanks! NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAlo5ds8ACgkQOeye3VZi gblXmg//bcDS7DOWR4rCid9hd+F6z28fL5I5FqOCglnEgUINPwTPfI08GHVpikw5 3gV8s7+L95apaGCe9HB5m1YJ27hFAAPs1j65L2Fn53GklJPUyQKZkv1ttqytVkG3 hxrONOc/S499y4fyu14qaFTu53OV1I2j0w5kM6N9l36pKNnO+yuO7NJ3t80mi/j3 0zRu6n3GHRoTTgwU29cNXEVEE6kcDm6Fm6/zsmBvISc4SLAPawVi4jCKDe/6yxaO oaFHM2SKyT7REtiyLBLuclohnlyTmqhIWy4+T1zw4nXZo/af5wPs5c5rQ4VmRVWa 9DvcZ4Au+fR8NRnCzm2RVdlo+77NhTINcr1ZqjRG9tmxkhxUL/TmDSwlnUQFN7J5 Amu7UYAamVjQmSapuoz3eC418hiQ1WruOHKR/j16BKy8Nxv5bBSxgW1I/1FY5o8Y htsZWdxSRgOg0QeIJ2WnNj+b02ap3UZpiwSbFGYfCt3CiHm4Rddg4G5Zd+6Qjx3A dObEBa0z+d7FGeOABIcZ4PKDGxWkEbYJR9ixIZtarq4/ONX8feXgK3eyLeCOb5HC LVrL3DLE5Jz4G7NXpt6mSoLMoubLMX+t6bGWFsv4sovHi4FHCm7gXou6Y0qxk5MX cC6E1wa3LMNLC6LeTV8IcaVf1FI6IPKvB8gl+1s773Z8VMHn9/k= =ij3v -----END PGP SIGNATURE----- --=-=-=--