From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2B9FC433DF for ; Mon, 17 Aug 2020 14:33:51 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B990F20729 for ; Mon, 17 Aug 2020 14:33:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EKK6PoaG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B990F20729 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40142 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k7gCs-0000Zd-Uh for qemu-devel@archiver.kernel.org; Mon, 17 Aug 2020 10:33:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39108) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k7gBU-0007l8-9u for qemu-devel@nongnu.org; Mon, 17 Aug 2020 10:32:24 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:33479 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k7gBS-0005Pk-My for qemu-devel@nongnu.org; Mon, 17 Aug 2020 10:32:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597674742; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=YBnsjl6ze2iohKw6BGYh6iqg7LSmlOG8JJnZsS7BVY8=; b=EKK6PoaGv1QbmCYSe14wC86qU26TtRaWIqfV9rcWK0tECqYfUtc80VFhlWvwi5pQfyI7R8 3684REEwVhMsbGHP5Tf0mU06/APxVtN9aCy1HBcQT33s99XdoLBQ5RKgOoK2Mr8CKH4eEx wEJUic0H9jKBchMhe7dCXIwu2lTk4Cg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-85-PUeaNLpsNDu8Egi0pMR3gQ-1; Mon, 17 Aug 2020 10:32:17 -0400 X-MC-Unique: PUeaNLpsNDu8Egi0pMR3gQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DE1A9425D2; Mon, 17 Aug 2020 14:32:16 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-113-146.ams2.redhat.com [10.36.113.146]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5D28A5C652; Mon, 17 Aug 2020 14:32:14 +0000 (UTC) Subject: Re: [RFC PATCH 12/22] nbd/server: Simplify export shutdown To: Kevin Wolf , qemu-block@nongnu.org References: <20200813162935.210070-1-kwolf@redhat.com> <20200813162935.210070-13-kwolf@redhat.com> From: Max Reitz Autocrypt: addr=mreitz@redhat.com; prefer-encrypt=mutual; keydata= mQENBFXOJlcBCADEyyhOTsoa/2ujoTRAJj4MKA21dkxxELVj3cuILpLTmtachWj7QW+TVG8U /PsMCFbpwsQR7oEy8eHHZwuGQsNpEtNC2G/L8Yka0BIBzv7dEgrPzIu+W3anZXQW4702+uES U29G8TP/NGfXRRHGlbBIH9KNUnOSUD2vRtpOLXkWsV5CN6vQFYgQfFvmp5ZpPeUe6xNplu8V mcTw8OSEDW/ZnxJc8TekCKZSpdzYoxfzjm7xGmZqB18VFwgJZlIibt1HE0EB4w5GsD7x5ekh awIe3RwoZgZDLQMdOitJ1tUc8aqaxvgA4tz6J6st8D8pS//m1gAoYJWGwwIVj1DjTYLtABEB AAG0HU1heCBSZWl0eiA8bXJlaXR6QHJlZGhhdC5jb20+iQFTBBMBCAA9AhsDBQkSzAMABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheABQJVzie5FRhoa3A6Ly9rZXlzLmdudXBnLm5ldAAKCRD0 B9sAYdXPQDcIB/9uNkbYEex1rHKz3mr12uxYMwLOOFY9fstP5aoVJQ1nWQVB6m2cfKGdcRe1 2/nFaHSNAzT0NnKz2MjhZVmcrpyd2Gp2QyISCfb1FbT82GMtXFj1wiHmPb3CixYmWGQUUh+I AvUqsevLA+WihgBUyaJq/vuDVM1/K9Un+w+Tz5vpeMidlIsTYhcsMhn0L9wlCjoucljvbDy/ 8C9L2DUdgi3XTa0ORKeflUhdL4gucWoAMrKX2nmPjBMKLgU7WLBc8AtV+84b9OWFML6NEyo4 4cP7cM/07VlJK53pqNg5cHtnWwjHcbpGkQvx6RUx6F1My3y52vM24rNUA3+ligVEgPYBuQEN BFXOJlcBCADAmcVUNTWT6yLWQHvxZ0o47KCP8OcLqD+67T0RCe6d0LP8GsWtrJdeDIQk+T+F xO7DolQPS6iQ6Ak2/lJaPX8L0BkEAiMuLCKFU6Bn3lFOkrQeKp3u05wCSV1iKnhg0UPji9V2 W5eNfy8F4ZQHpeGUGy+liGXlxqkeRVhLyevUqfU0WgNqAJpfhHSGpBgihUupmyUg7lfUPeRM DzAN1pIqoFuxnN+BRHdAecpsLcbR8sQddXmDg9BpSKozO/JyBmaS1RlquI8HERQoe6EynJhd 64aICHDfj61rp+/0jTIcevxIIAzW70IadoS/y3DVIkuhncgDBvGbF3aBtjrJVP+5ABEBAAGJ ASUEGAEIAA8FAlXOJlcCGwwFCRLMAwAACgkQ9AfbAGHVz0CbFwf9F/PXxQR9i4N0iipISYjU sxVdjJOM2TMut+ZZcQ6NSMvhZ0ogQxJ+iEQ5OjnIputKvPVd5U7WRh+4lF1lB/NQGrGZQ1ic alkj6ocscQyFwfib+xIe9w8TG1CVGkII7+TbS5pXHRxZH1niaRpoi/hYtgzkuOPp35jJyqT/ /ELbqQTDAWcqtJhzxKLE/ugcOMK520dJDeb6x2xVES+S5LXby0D4juZlvUj+1fwZu+7Io5+B bkhSVPb/QdOVTpnz7zWNyNw+OONo1aBUKkhq2UIByYXgORPFnbfMY7QWHcjpBVw9MgC4tGeF R4bv+1nAMMxKmb5VvQCExr0eFhJUAHAhVg== Message-ID: <267f48dd-045b-ae4e-9b7f-46339a270eea@redhat.com> Date: Mon, 17 Aug 2020 16:32:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200813162935.210070-13-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0.0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SBMdVMtSq4fe0mar4C4VmjEve6XhteeRz" Received-SPF: pass client-ip=207.211.31.120; envelope-from=mreitz@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/17 00:24:04 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --SBMdVMtSq4fe0mar4C4VmjEve6XhteeRz Content-Type: multipart/mixed; boundary="9O6cwcvWeCM2f2n3gBDXhQRaUjAPniZnR" --9O6cwcvWeCM2f2n3gBDXhQRaUjAPniZnR Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 13.08.20 18:29, Kevin Wolf wrote: > Closing export is somewhat convoluted because nbd_export_close() and > nbd_export_put() call each other and the ways they actually end up being > nested is not necessarily obvious. >=20 > However, it is not really necessary to call nbd_export_close() from > nbd_export_put() when putting the last reference because it only does > three things: >=20 > 1. Close all clients. We're going to refcount 0 and all clients hold a > reference, so we know there is no active client any more. >=20 > 2. Close the user reference (represented by exp->name being non-NULL). > The same argument applies: If the export were still named, we would > still have a reference. >=20 > 3. Freeing exp->description. This is really cleanup work to be done when > the export is finally freed. There is no reason to already clear it > while clients are still in the process of shutting down. Convincing. > So after moving the cleanup of exp->description, the code can be > simplified so that only nbd_export_close() calls nbd_export_put(), but > never the other way around. >=20 > Signed-off-by: Kevin Wolf > --- > nbd/server.c | 17 ++++------------- > 1 file changed, 4 insertions(+), 13 deletions(-) Reviewed-by: Max Reitz --9O6cwcvWeCM2f2n3gBDXhQRaUjAPniZnR-- --SBMdVMtSq4fe0mar4C4VmjEve6XhteeRz Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl86lOwACgkQ9AfbAGHV z0CcuAf/TboMdmloElWa5hgjdNNQ5N+Mc9DkNxeqcBsJ5GIyDIjsNg4yB0Q1LmQo uSuSa2QAncYuZBWIBj0IyVk413XrYGkPyRPBVYYBZp53KuyBRMQ94fL+iuHqJX1S q3/1sKUkf3nANADjuu3nW9BRJs+nIS5VmUlgLpIqpTRJ9YAvDPUx2NC1Kqis/w0i /NxXhNR8dez9l9fUele7ljj6mfv+d68brtq87KhqFWLvnXn3u25j2YyOa8dhIfsy fVNajUkvyi2O3EmCwARkmKFgPMPmotdddxXgS6BXeFUZ6Lr8cCzTtVkd1zHR0HUz nX4UnKrnNwV1mhmpGHE1FCAhy2lTlw== =lh98 -----END PGP SIGNATURE----- --SBMdVMtSq4fe0mar4C4VmjEve6XhteeRz--