From owner-freebsd-fs@freebsd.org Sat Sep 9 21:53:28 2017 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8BAAAE0CA4E for ; Sat, 9 Sep 2017 21:53:28 +0000 (UTC) (envelope-from Nikolaus@rath.org) Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 5B3437F155 for ; Sat, 9 Sep 2017 21:53:27 +0000 (UTC) (envelope-from Nikolaus@rath.org) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 2D8AD210AF for ; Sat, 9 Sep 2017 17:53:21 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute1.internal (MEProxy); Sat, 09 Sep 2017 17:53:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= fm1; bh=AWgC1uNeU/HTQFc5T/rtTrd27K5zTUpZP/0k0FoSK0o=; b=B7UmXxA/ YhvPpEoiw+rBw0EGHcC9WyN1hD3DieKXEpvL0qf1RPUarrt3MHoPrvKUeFACAWSP ITjzGSgGlsqQ7dYRHyMYWJlxmk3vh0ydiGALLkg4nGnIuOd/wnMxqToz/o8XAzm2 hJrEvwWAdYvR4VXeOk2kBrZT7dtN2eid2AntZV9+19zPg0W5RQe96UufxdhCLPy4 eXajaiyuCVCfYo0pHqHwOhIHfOkCR9YSlVc2FG9KZV8fiHagrHkkDxKEKNX48eVm AAuzLsHykbtcyWgZJQhZPkFig3FRCpjf+d6/8dR35pZ7d8AqDeoOxvDy8UQ6EQhh hHl27bvLzg1cJg== X-ME-Sender: X-Sasl-enc: DLZjO9TiCWP9xM4okN71J4+Ujkjz6bbzYl6YEtlMnBYS 1504994000 Received: from ebox.rath.org (ebox.rath.org [45.79.69.51]) by mail.messagingengine.com (Postfix) with ESMTPA id E0E1B7F9CE for ; Sat, 9 Sep 2017 17:53:20 -0400 (EDT) Received: from vostro.rath.org (vostro [192.168.12.4]) by ebox.rath.org (Postfix) with ESMTPS id 021A1EC for ; Sat, 9 Sep 2017 21:53:20 +0000 (UTC) Received: by vostro.rath.org (Postfix, from userid 1000) id 9B393102BD7; Sat, 9 Sep 2017 22:53:18 +0100 (BST) From: Nikolaus Rath To: freebsd-fs@freebsd.org Subject: Re: umount() taking minutes for FUSE filesystems References: <87bmn44ruu.fsf@vostro.rath.org> <87o9qyrbs8.fsf@vostro.rath.org> <2FAD66DE-031B-4B36-9E85-C7BC6B52B5E6@gmail.com> <29de6425-9f92-3bd8-f446-1c9dded33b15@freebsd.org> <87k21dzdrp.fsf@thinkpad.rath.org> <201709051811.v85IBmbO005440@higson.cam.lispworks.com> <87ingugw2v.fsf@thinkpad.rath.org> <201709081143.v88BhEOn001626@higson.cam.lispworks.com> <87lglp6zj8.fsf@vostro.rath.org> <201709081728.v88HSXP7010329@higson.cam.lispworks.com> Mail-Copies-To: never Mail-Followup-To: freebsd-fs@freebsd.org Date: Sat, 09 Sep 2017 22:53:18 +0100 In-Reply-To: <201709081728.v88HSXP7010329@higson.cam.lispworks.com> (Martin Simmons's message of "Fri, 8 Sep 2017 18:28:33 +0100") Message-ID: <87ingr7d4h.fsf@vostro.rath.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Sep 2017 21:53:28 -0000 On Sep 08 2017, Martin Simmons wrote: >> That said, the filesystem could also detect the unmount by the kernel >> closing the fd. So I'm not sure what is gained by the extra request >> either... Theoretically, at least under Linux the destroy handler could >> perform some notify_* operations, but I don't see how that would be >> useful when the filesystem will be unmounted anyway. > > I don't think the kernel itself ever closes the fd (except implicitly in = the > case where the filesystem program dies unexpected). Sorry, I should have been more precise. The umount is not detected by the kernel closing the fd, but by the kernel returning ENODEV when accessing the fd. Best, -Nikolaus --=20 GPG Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F =C2=BBTime flies like an arrow, fruit flies like a Banana.=C2= =AB