From patchwork Mon Feb 8 22:40:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 12076895 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 41A4DC433E0 for ; Tue, 9 Feb 2021 00:10:24 +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 E4DC064DDB for ; Tue, 9 Feb 2021 00:10:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4DC064DDB 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]:49366 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9Gbh-0005oZ-2i for qemu-devel@archiver.kernel.org; Mon, 08 Feb 2021 19:10:19 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56808) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9FD7-0005Ee-2Q for qemu-devel@nongnu.org; Mon, 08 Feb 2021 17:40:49 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:23440) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l9FD1-0006Xt-Fx for qemu-devel@nongnu.org; Mon, 08 Feb 2021 17:40:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612824041; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SivcshdWiTpCJT5ZjThs9jcwl4uv8Miq82xhjYqSxro=; b=XqfSmlPgcF8TmDw9RHaJ4jREEKrt5guuP0Axi0HLvTo1INulQXO9JhUXywQU0ydoNtG7So JcjGKMOm0fA3naOKRfMgv24P6IfOdecO8kMzlMNf6Z3gijQnmspG4QLWmmBYroYj0YDSGV t87kzV+/5FMSs4yGVmhoJkUxORxGZvk= 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-388-7_-9_EjbNXy6zT381Cx50A-1; Mon, 08 Feb 2021 17:40:39 -0500 X-MC-Unique: 7_-9_EjbNXy6zT381Cx50A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 75FB21966320; Mon, 8 Feb 2021 22:40:38 +0000 (UTC) Received: from horse.redhat.com (ovpn-115-237.rdu2.redhat.com [10.10.115.237]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D80660C5B; Mon, 8 Feb 2021 22:40:32 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id D1EF9223D98; Mon, 8 Feb 2021 17:40:31 -0500 (EST) From: Vivek Goyal To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH v3 1/2] virtiofsd: Save error code early at the failure callsite Date: Mon, 8 Feb 2021 17:40:23 -0500 Message-Id: <20210208224024.43555-2-vgoyal@redhat.com> In-Reply-To: <20210208224024.43555-1-vgoyal@redhat.com> References: <20210208224024.43555-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vgoyal@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: mszeredi@redhat.com, stefanha@redhat.com, dgilbert@redhat.com, vgoyal@redhat.com, groug@kaod.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Change error code handling slightly in lo_setattr(). Right now we seem to jump to out_err and assume that "errno" is valid and use that to send reply. But if caller has to do some other operations before jumping to out_err, then it does the dance of first saving errno to saverr and the restore errno before jumping to out_err. This makes it more confusing. I am about to make more changes where caller will have to do some work after error before jumping to out_err. I found it easier to change the convention a bit. That is caller saves error in "saverr" before jumping to out_err. And out_err uses "saverr" to send error back and does not rely on "errno" having actual error. v3: Resolved conflicts in lo_setattr() due to lo_inode_open() changes. Signed-off-by: Vivek Goyal Reviewed-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 147b59338a..5dd6a4a4a6 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -698,6 +698,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, res = fchmodat(lo->proc_self_fd, procname, attr->st_mode, 0); } if (res == -1) { + saverr = errno; goto out_err; } } @@ -707,6 +708,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, res = fchownat(ifd, "", uid, gid, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW); if (res == -1) { + saverr = errno; goto out_err; } } @@ -718,16 +720,15 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, } else { truncfd = lo_inode_open(lo, inode, O_RDWR); if (truncfd < 0) { - errno = -truncfd; + saverr = -truncfd; goto out_err; } } res = ftruncate(truncfd, attr->st_size); + saverr = res == -1 ? errno : 0; if (!fi) { - saverr = errno; close(truncfd); - errno = saverr; } if (res == -1) { goto out_err; @@ -760,6 +761,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, res = utimensat(lo->proc_self_fd, procname, tv, 0); } if (res == -1) { + saverr = errno; goto out_err; } } @@ -768,7 +770,6 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, return lo_getattr(req, ino, fi); out_err: - saverr = errno; lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); }