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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C36E9C433EF for ; Thu, 21 Apr 2022 17:05:34 +0000 (UTC) Received: from localhost ([::1]:54302 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nhaFJ-0001fN-LS for qemu-devel@archiver.kernel.org; Thu, 21 Apr 2022 13:05:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34888) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nhZqZ-00077u-TR for qemu-devel@nongnu.org; Thu, 21 Apr 2022 12:40:00 -0400 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:44827) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nhZqO-0002gZ-4D for qemu-devel@nongnu.org; Thu, 21 Apr 2022 12:39:49 -0400 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-669-BYCwZ-a1M0On5axwtwNxJg-1; Thu, 21 Apr 2022 12:39:40 -0400 X-MC-Unique: BYCwZ-a1M0On5axwtwNxJg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A4251833960; Thu, 21 Apr 2022 16:39:39 +0000 (UTC) Received: from bahia (unknown [10.39.192.169]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8126154FB82; Thu, 21 Apr 2022 16:39:38 +0000 (UTC) Date: Thu, 21 Apr 2022 18:39:37 +0200 From: Greg Kurz To: Christian Schoenebeck Subject: Re: [PATCH v2 4/5] 9pfs: fix wrong errno being sent to Linux client on macOS host Message-ID: <20220421183937.21531b9a@bahia> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Received-SPF: softfail client-ip=207.211.30.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org, qemu-stable@nongnu.org, Keno Fischer , Michael Roitzsch , Will Cohen , Akihiko Odaki Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 21 Apr 2022 17:07:49 +0200 Christian Schoenebeck wrote: > Linux and macOS only share some errno definitions with equal macro > name and value. In fact most mappings for errno are completely > different on the two systems. > > This patch converts some important errno values from macOS host to > corresponding Linux errno values before eventually sending such error > codes along with 'Rlerror' replies (if 9p2000.L is used that is). Not > having translated errnos before violated the 9p2000.L protocol spec, > which says: > > " > size[4] Rlerror tag[2] ecode[4] > > ... ecode is a numerical Linux errno. > " > > https://github.com/chaos/diod/wiki/protocol#lerror----return-error-code > > This patch fixes a bunch of misbehaviours when running a Linux client > on macOS host. For instance this patch fixes: > > mount -t 9p -o posixacl ... > > on Linux guest if security_mode=mapped was used for 9p server, which > refused to mount successfully, because macOS returned ENOATTR==93 > when client tried to retrieve POSIX ACL xattrs, because errno 93 > is defined as EPROTONOSUPPORT==93 on Linux, so Linux client believed > that xattrs were not supported by filesystem on host in general. > > Signed-off-by: Christian Schoenebeck > Link: https://lore.kernel.org/qemu-devel/20220421124835.3e664669@bahia/ > --- Reviewed-by: Greg Kurz > hw/9pfs/9p-util.h | 30 ++++++++++++++++++++++++++++++ > hw/9pfs/9p.c | 2 ++ > 2 files changed, 32 insertions(+) > > diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h > index 2cc9a5dbfb..c3526144c9 100644 > --- a/hw/9pfs/9p-util.h > +++ b/hw/9pfs/9p-util.h > @@ -58,6 +58,36 @@ static inline uint64_t host_dev_to_dotl_dev(dev_t dev) > #endif > } > > +/* Translates errno from host -> Linux if needed */ > +static inline int errno_to_dotl(int err) { > +#if defined(CONFIG_LINUX) > + /* nothing to translate (Linux -> Linux) */ > +#elif defined(CONFIG_DARWIN) > + /* > + * translation mandatory for macOS hosts > + * > + * FIXME: Only most important errnos translated here yet, this should be > + * extended to as many errnos being translated as possible in future. > + */ > + if (err == ENAMETOOLONG) { > + err = 36; /* ==ENAMETOOLONG on Linux */ > + } else if (err == ENOTEMPTY) { > + err = 39; /* ==ENOTEMPTY on Linux */ > + } else if (err == ELOOP) { > + err = 40; /* ==ELOOP on Linux */ > + } else if (err == ENOATTR) { > + err = 61; /* ==ENODATA on Linux */ > + } else if (err == ENOTSUP) { > + err = 95; /* ==EOPNOTSUPP on Linux */ > + } else if (err == EOPNOTSUPP) { > + err = 95; /* ==EOPNOTSUPP on Linux */ > + } > +#else > +#error Missing errno translation to Linux for this host system > +#endif > + return err; > +} > + > #ifdef CONFIG_DARWIN > #define qemu_fgetxattr(...) fgetxattr(__VA_ARGS__, 0, 0) > #define qemu_lgetxattr(...) getxattr(__VA_ARGS__, 0, XATTR_NOFOLLOW) > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > index 4a296a0b94..0cd0c14c2a 100644 > --- a/hw/9pfs/9p.c > +++ b/hw/9pfs/9p.c > @@ -1054,6 +1054,8 @@ static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t len) > } > len += ret; > id = P9_RERROR; > + } else { > + err = errno_to_dotl(err); > } > > ret = pdu_marshal(pdu, len, "d", err);