From patchwork Mon May 11 16:09:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 11541261 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 49A6392A for ; Mon, 11 May 2020 16:11:14 +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 214152070B for ; Mon, 11 May 2020 16:11:13 +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="MCkO2T+m" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 214152070B 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:56456 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYB1N-0003sE-3v for patchwork-qemu-devel@patchwork.kernel.org; Mon, 11 May 2020 12:11:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48214) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYB0G-00028D-R7 for qemu-devel@nongnu.org; Mon, 11 May 2020 12:10:04 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:44719 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 1jYB0G-000140-0y for qemu-devel@nongnu.org; Mon, 11 May 2020 12:10:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589213402; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:content-type:content-type:in-reply-to:in-reply-to: references:references; bh=LqVzIZeE/iyxPQdzaM/w9wa3okOVbVjc1YkNbxM6+O8=; b=MCkO2T+mhC+wB4FLVCRT1xvBWOKa6p5gPZmO6iTEfbIQyiv0Wul7Epkr8sddVRcs7jbOUA Pijk3EMZ2qZapcju/SyJrGbaTqC4caKqBbhVmGQEDtQqX2M0iPGbyRVhcN/9JG+4Oe1Vgq x2Q/blkDxE97b1u7hXQOtnbYpJ3fOZk= 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-176-7IGT1_-MNsy0ZlNrZjQD6w-1; Mon, 11 May 2020 12:10:00 -0400 X-MC-Unique: 7IGT1_-MNsy0ZlNrZjQD6w-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 C38D2107ACCA; Mon, 11 May 2020 16:09:59 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id DF4F25C1B5; Mon, 11 May 2020 16:09:57 +0000 (UTC) From: Maxim Levitsky To: qemu-devel@nongnu.org Subject: [PATCH v2 1/7] scsi/scsi_bus: switch search direction in scsi_device_find Date: Mon, 11 May 2020 19:09:45 +0300 Message-Id: <20200511160951.8733-2-mlevitsk@redhat.com> In-Reply-To: <20200511160951.8733-1-mlevitsk@redhat.com> References: <20200511160951.8733-1-mlevitsk@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.120; envelope-from=mlevitsk@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/11 00:05:06 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, 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_H2=-0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN 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: Fam Zheng , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Eduardo Habkost , "Michael S. Tsirkin" , Maxim Levitsky , Paolo Bonzini Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" This change will allow us to convert the bus children list to RCU, while not changing the logic of this function Signed-off-by: Maxim Levitsky Reviewed-by: Stefan Hajnoczi --- hw/scsi/scsi-bus.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index 1c980cab38..7bbc37acec 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -1584,7 +1584,7 @@ SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun) BusChild *kid; SCSIDevice *target_dev = NULL; - QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, sibling) { + QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { DeviceState *qdev = kid->child; SCSIDevice *dev = SCSI_DEVICE(qdev); @@ -1592,7 +1592,15 @@ SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun) if (dev->lun == lun) { return dev; } - target_dev = dev; + + /* + * If we don't find exact match (channel/bus/lun), + * we will return the first device which matches channel/bus + */ + + if (!target_dev) { + target_dev = dev; + } } } return target_dev;