From owner-svn-src-head@FreeBSD.ORG Wed Sep 15 14:57:17 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 079CE106564A; Wed, 15 Sep 2010 14:57:17 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-qy0-f182.google.com (mail-qy0-f182.google.com [209.85.216.182]) by mx1.freebsd.org (Postfix) with ESMTP id 8314A8FC14; Wed, 15 Sep 2010 14:57:16 +0000 (UTC) Received: by qyk4 with SMTP id 4so310326qyk.13 for ; Wed, 15 Sep 2010 07:57:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=fFv90CruJv7ZmWxQa2IjiiOCxhQm29P1ACNVVm47L8c=; b=r3P6wzDuJ7Pv7ItaaId01YgMkbRINDVFTXGWfK5ZssH9yJMx+a0VlVgYWXURdUFvwI kxNqL2IJtUYXBCWjJzb3rPp1D8mQdO2VGWe3/KFqLBqiQoYqfrzOptdrt6AQVzbBVcsP lWSthqwbREh/o81RwCCwaFlAr7iV30mwBlcxw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=LzrOC56vrVzM09VAC7MFJWQM8U6sKI8Bq38UN2GLE0Tv/9pxOjKql7bxAa0rGsY8GO rbna5ew8ngolpJIxUtXJHWT+dirzj5t7ZnsCPKY+Qz8GVxdatRTTszzqCQwW3rPt9FI+ /8//6cqFIg0WmxI5OYMSUhDT1L7YWSQmEbzGo= MIME-Version: 1.0 Received: by 10.224.64.85 with SMTP id d21mr1107082qai.367.1284562635670; Wed, 15 Sep 2010 07:57:15 -0700 (PDT) Sender: asmrookie@gmail.com Received: by 10.229.49.196 with HTTP; Wed, 15 Sep 2010 07:57:15 -0700 (PDT) In-Reply-To: <20100915145209.GK2465@deviant.kiev.zoral.com.ua> References: <201009151424.o8FEOLZE039185@svn.freebsd.org> <20100915145209.GK2465@deviant.kiev.zoral.com.ua> Date: Wed, 15 Sep 2010 16:57:15 +0200 X-Google-Sender-Auth: uK85kii4m2R244vZEk_iM_RjU6g Message-ID: From: Attilio Rao To: Kostik Belousov Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r212661 - head/sys/dev/aac X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Sep 2010 14:57:17 -0000 2010/9/15 Kostik Belousov : > On Wed, Sep 15, 2010 at 02:24:21PM +0000, Attilio Rao wrote: >> Author: attilio >> Date: Wed Sep 15 14:24:21 2010 >> New Revision: 212661 >> URL: http://svn.freebsd.org/changeset/base/212661 >> >> Log: >> =C2=A0 Fix bogus busying mechanism from cdevsw callbacks: >> =C2=A0 - D_TRACKCLOSE may be used there as d_close() are expected to mat= ch up >> =C2=A0 =C2=A0 d_open() calls > VFS is not very good at properly calling VOP_CLOSE(). As example, prematu= re > vnode reclaim due to devfs unmount would cause VOP_CLOSE() to be called > only once despite the number of opens being =C2=A0> 1. Yes. That makes implementing a similar semantic in drivers very difficult and not very well fixable, in particular within the d_* callbacks. I'm seriously wondering if we might just make a shortcut just for supporting such a feature (busying the device on real devfs entry activity) as several of them may be needing and may be probabilly needing to be 100%. Luckilly, it seems that such paths are not experienced very frequently. Attilio --=20 Peace can only be achieved by understanding - A. Einstein