Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-bk0-f46.google.com ([209.85.214.46]:42470 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752286Ab2FKOEg (ORCPT ); Mon, 11 Jun 2012 10:04:36 -0400 Received: by bkcji2 with SMTP id ji2so3556949bkc.19 for ; Mon, 11 Jun 2012 07:04:35 -0700 (PDT) Message-ID: <4FD5FAEF.5040004@tonian.com> Date: Mon, 11 Jun 2012 17:04:31 +0300 From: Benny Halevy MIME-Version: 1.0 To: Boaz Harrosh CC: "Welch, Brent" , "Bhamare, Sachin" , "Adamson, Andy" , Andy Adamson , "Myklebust, Trond" , "" , "Huang, James" Subject: Re: [PATCH 2/3] NFSv4.1 mark layout when already returned References: <1338571178-2096-1-git-send-email-andros@netapp.com> <1338571178-2096-2-git-send-email-andros@netapp.com> <4FCA98E7.2030006@panasas.com> <1C92D18B-1977-4A12-A4DA-84DAC4B3E81E@netapp.com> <4FCE1DC1.6050100@panasas.com> <4FD5C0EA.806@tonian.com> <4FD5CBF6.6030800@panasas.com> In-Reply-To: <4FD5CBF6.6030800@panasas.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 2012-06-11 13:44, Boaz Harrosh wrote: > On 06/11/2012 12:56 PM, Benny Halevy wrote: > >> >> It will for recovering files striped with RAID as the LAYOUTRETURN >> provides the server with a reliable "commit point" where it knows >> exactly what was written successfully to each stripe and can make >> the most efficient decision about recovering it (if needed). >> >> Allowing I/O to the stripe post LAYOUTRETURN may result in data >> corruption due to parity inconsistency. >> > > > The fact of the matter is that we - object guys - Which care about > LAYOUTRETURN the most, have neglected to notice and fix the current > situation which is even worse than After Andy's patch. Which will > send multiple LAYOUTRETURNs on the same layout, and might still > continue IO on returned layouts. > > Thanks Andy for testing and highlighting the current problem, > I will prioritized this development internally at Panasas and > will work on a solution ASAP. I hope one that will satisfy > all. > > Basically my plan is to postpone the LAYOUTRETURN send to > when the segment is last referenced, if a flag was set to > do so, and make sure reference counting is done proper, so > after flag set the last IO_done will send the LAYOUTRETURN. > > If that is OK with all I hope? Sounds OK to me. Thanks! Benny > >> Benny >> > > > Thanks > Boaz >