From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: pread() over NFS (again) [1.5.5.4] Date: Thu, 26 Jun 2008 22:54:13 -0400 Message-ID: <20080627025413.GA19568@fieldses.org> References: <6F25C1B4-85DE-4559-9471-BCD453FEB174@gmail.com> <20080626204606.GX11793@spearce.org> <7vskuzq5ix.fsf@gitster.siamese.dyndns.org> <65688C06-BB6A-4E95-A4B9-A1A7C206BE2E@sent.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Junio C Hamano , "Shawn O. Pearce" , Christian Holtje , git@vger.kernel.org To: logank@sent.com X-From: git-owner@vger.kernel.org Fri Jun 27 04:55:21 2008 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1KC47L-0004eI-83 for gcvg-git-2@gmane.org; Fri, 27 Jun 2008 04:55:19 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753293AbYF0CyX (ORCPT ); Thu, 26 Jun 2008 22:54:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753116AbYF0CyW (ORCPT ); Thu, 26 Jun 2008 22:54:22 -0400 Received: from mail.fieldses.org ([66.93.2.214]:43399 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752434AbYF0CyW (ORCPT ); Thu, 26 Jun 2008 22:54:22 -0400 Received: from bfields by fieldses.org with local (Exim 4.69) (envelope-from ) id 1KC46H-00059l-IH; Thu, 26 Jun 2008 22:54:13 -0400 Content-Disposition: inline In-Reply-To: <65688C06-BB6A-4E95-A4B9-A1A7C206BE2E@sent.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Thu, Jun 26, 2008 at 04:36:27PM -0700, logank@sent.com wrote: > On Jun 26, 2008, at 1:56 PM, Junio C Hamano wrote: > >>> "The file shouldn't be short unless someone truncated it, or there >>> is a bug in index-pack. Neither is very likely, but I don't think >>> we would want to retry pread'ing the same block forever. >> >> I don't think we would want to retry even once. Return value of 0 >> from >> pread is defined to be an EOF, isn't it? > > No, it seems to be a simple error-out in this case. We have 2.4.20 > systems That version's for the client or the server? --b. > with nfs-utils 0.3.3 and used to frequently get the same error > while pushing. I made a similar change back in February and haven't had a > problem since: > > diff --git a/index-pack.c b/index-pack.c > index 5ac91ba..85c8bdb 100644 > --- a/index-pack.c > +++ b/index-pack.c > @@ -313,7 +313,14 @@ static void *get_data_from_pack(struct object_entry > *obj) > src = xmalloc(len); > data = src; > do { > + // It appears that if multiple threads read across NFS, the > + // second read will fail. I know this is awful, but we wait for > + // a little bit and try again. > ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy); > + if (n <= 0) { > + sleep(1); > + n = pread(pack_fd, data + rdy, len - rdy, from + rdy); > + } > if (n <= 0) > die("cannot pread pack file: %s", strerror(errno)); > rdy += n; > > I use a sleep request since it seems less likely that the other thread > will have an outstanding request after a second of waiting. > > -- > Logan Kennelly > ,,, > (. .) > --ooO-(_)-Ooo-- > > > > -- > To unsubscribe from this list: send the line "unsubscribe git" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html