From owner-freebsd-hackers@FreeBSD.ORG Sun Jun 9 01:36:27 2013 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id B22FA955 for ; Sun, 9 Jun 2013 01:36:27 +0000 (UTC) (envelope-from mdf356@gmail.com) Received: from mail-ob0-x22d.google.com (mail-ob0-x22d.google.com [IPv6:2607:f8b0:4003:c01::22d]) by mx1.freebsd.org (Postfix) with ESMTP id 818F01366 for ; Sun, 9 Jun 2013 01:36:27 +0000 (UTC) Received: by mail-ob0-f173.google.com with SMTP id wc20so8540837obb.32 for ; Sat, 08 Jun 2013 18:36:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=ZJ20lXH3E0dABAFb2pDgncSdPPH/ShKIZcRGU9VyJqs=; b=CihDuuIndCRBbQD38OA8PiIPz46YnhUUXhCifwPPFByXbYsQzMMqNMaNB+VFAnXLdk HEMEBk/fV7HzkjMTUMQvZFbJTNRS5HkabqBQXwdlbNXLikwTt5QYvyZAq1NcQluwy9lk C5759XRkwfZ+WDEQOwtFcJHAXDVqNoj5+PBkoU4AegZ35Cgk5ByohL3hnhWAY2TqrnBP I7W56cK/s9L5cytiP6hIksWWsQHDzdIkk9KP58TBTZy18xKtjXJdbK6noiiAcp4Cps+h XHuiCh45n1R/2t0W+dxXGuagRpSox0s9a4Uf3JwptZbQHAROWbx92vjX8DvoFPP0Zg+5 xgEQ== MIME-Version: 1.0 X-Received: by 10.60.174.111 with SMTP id br15mr3508491oec.130.1370741787087; Sat, 08 Jun 2013 18:36:27 -0700 (PDT) Sender: mdf356@gmail.com Received: by 10.182.237.100 with HTTP; Sat, 8 Jun 2013 18:36:27 -0700 (PDT) In-Reply-To: <51B3B59B.8050903@erdgeist.org> References: <51B3B59B.8050903@erdgeist.org> Date: Sat, 8 Jun 2013 18:36:27 -0700 X-Google-Sender-Auth: k_4I3ooPAUOOp_KcVnt3FXwnNz0 Message-ID: Subject: Re: Fix MNAMELEN or reimplement struct statfs From: mdf@FreeBSD.org To: Dirk Engling Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: FreeBSD Hackers X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 09 Jun 2013 01:36:27 -0000 On Sat, Jun 8, 2013 at 3:52 PM, Dirk Engling wrote: > The arbitrary value > > #define MNAMELEN 88 /* size of on/from name bufs */ > > struct statfs { > [...] > char f_mntfromname[MNAMELEN];/* mounted filesystem */ > char f_mntonname[MNAMELEN]; /* directory on which mounted */ > }; > > currently bites us when trying to use poudriere with errors like > > 'mount: tmpfs: File name too long' > > > /poudriere/data/build/91_RELEASE_amd64-REALLY-REALLY-LONG-JAILNAME/ref/wrkdirs > > The topic has been discussed several times since 2004 and has been > postponed each time, the last time when it hit zfs users: > > http://lists.freebsd.org/pipermail/freebsd-fs/2010-March/007974.html > > So I'd like to point to the calendar, it's 2013 already and there's > still a static arbitrary (and way too low) limit in one of the core > areas of the vfs code. > > So I'd like to bump the issue and propose either making f_mntfromname a > dynamic allocation or just increase MNAMELEN, using 10.0 as water shed. > Gleb Kurtsou did this along with the ino64 GSoC project. Unfortunately, both he and I hit ENOTIME due to the job that pays the bills and it's never made it back to the main repository. IIRC, though, the only reason for doing it with 64-bit ino_t is that he'd already finished changing the stat/dirent ABI so what was one more. I think he went with 1024 bytes, which also necessitated not allocating statfs on the stack for the kernel. Cheers, matthew