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(unknown [2a02:6bf:8080:b8f::1:11]) by mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id anf8gZ3GnW20-aGP1hrIK; Wed, 03 Sep 2025 15:49:37 +0300 Precedence: bulk X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1756903777; bh=JBEuKPIFGUuJUV939QSbdXyh7RXiG0DMIQMNx76sU+Q=; h=Message-ID:Date:In-Reply-To:Cc:Subject:References:To:From; b=vJXpCEkWpMZd8OP5rSWSE6sc5cvRY7P50aO7mEUY8MOesNgwZ6lxihdPNurkV+YOy LHUVtSGgRXnqOUCphj3regLabdlDc/HZMeIZcoAdhNT0a5nwKXN+b0tRJesSts0BtU jB3JFgYIG8PFvl4ttgYshKThD2E0Ac7xNVDThF1w= Authentication-Results: mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net; dkim=pass header.i=@yandex-team.ru From: Vladimir Sementsov-Ogievskiy To: jasowang@redhat.com Cc: qemu-devel@nongnu.org, vsementsov@yandex-team.ru, leiyang@redhat.com, steven.sistare@oracle.com, yc-core@yandex-team.ru Subject: [PATCH v3 01/19] net/tap: net_init_tap_one(): add return value Date: Wed, 3 Sep 2025 15:49:15 +0300 Message-ID: <20250903124934.1169899-2-vsementsov@yandex-team.ru> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250903124934.1169899-1-vsementsov@yandex-team.ru> References: <20250903124934.1169899-1-vsementsov@yandex-team.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=178.154.239.72; envelope-from=vsementsov@yandex-team.ru; helo=forwardcorp1a.mail.yandex.net 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @yandex-team.ru) X-ZM-MESSAGEID: 1756903872029116600 Content-Type: text/plain; charset="utf-8" To avoid error propagation, let's follow common recommendation to use return value together with errp. Probably, it would also be good to use bool as a return type (switching to true/false as success/failure instead of 0/-1). But seems almost all functions (including a lot of them with errp argument) have 0/-1 semantics in net/, so making exclusions doesn't seem good. If we want such a switch, we should update the whole net/ directory. Why do we prefer errp-based functions with return value? In short with additional return value we get: - less code to handle error - don't create and set Error object when it's not required (when passed errp=3DNULL) More details in commit message of e3fe3988d7851cac3 "error: Document Error API usage rules" Signed-off-by: Vladimir Sementsov-Ogievskiy Tested-by: Lei Yang --- net/tap.c | 55 +++++++++++++++++++++++++------------------------------ 1 file changed, 25 insertions(+), 30 deletions(-) diff --git a/net/tap.c b/net/tap.c index f37133e301..89feb01756 100644 --- a/net/tap.c +++ b/net/tap.c @@ -679,11 +679,11 @@ static int net_tap_init(const NetdevTapOptions *tap, = int *vnet_hdr, =20 #define MAX_TAP_QUEUES 1024 =20 -static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *= peer, - const char *model, const char *name, - const char *ifname, const char *script, - const char *downscript, const char *vhostfdna= me, - int vnet_hdr, int fd, Error **errp) +static int net_init_tap_one(const NetdevTapOptions *tap, NetClientState *p= eer, + const char *model, const char *name, + const char *ifname, const char *script, + const char *downscript, const char *vhostfdnam= e, + int vnet_hdr, int fd, Error **errp) { Error *err =3D NULL; TAPState *s =3D net_tap_fd_init(peer, model, name, fd, vnet_hdr); @@ -761,10 +761,11 @@ static void net_init_tap_one(const NetdevTapOptions *= tap, NetClientState *peer, goto failed; } =20 - return; + return 0; =20 failed: qemu_del_net_client(&s->nc); + return -1; } =20 static int get_fds(char *str, char *fds[], int max) @@ -801,7 +802,6 @@ int net_init_tap(const Netdev *netdev, const char *name, /* for the no-fd, no-helper case */ const char *script; const char *downscript; - Error *err =3D NULL; const char *vhostfdname; char ifname[128]; int ret =3D 0; @@ -846,12 +846,10 @@ int net_init_tap(const Netdev *netdev, const char *na= me, return -1; } =20 - net_init_tap_one(tap, peer, "tap", name, NULL, - script, downscript, - vhostfdname, vnet_hdr, fd, &err); - if (err) { - error_propagate(errp, err); - close(fd); + ret =3D net_init_tap_one(tap, peer, "tap", name, NULL, + script, downscript, + vhostfdname, vnet_hdr, fd, errp); + if (ret < 0) { return -1; } } else if (tap->fds) { @@ -907,12 +905,11 @@ int net_init_tap(const Netdev *netdev, const char *na= me, goto free_fail; } =20 - net_init_tap_one(tap, peer, "tap", name, ifname, - script, downscript, - tap->vhostfds ? vhost_fds[i] : NULL, - vnet_hdr, fd, &err); - if (err) { - error_propagate(errp, err); + ret =3D net_init_tap_one(tap, peer, "tap", name, ifname, + script, downscript, + tap->vhostfds ? vhost_fds[i] : NULL, + vnet_hdr, fd, errp); + if (ret < 0) { ret =3D -1; goto free_fail; } @@ -952,11 +949,10 @@ free_fail: return -1; } =20 - net_init_tap_one(tap, peer, "bridge", name, ifname, - script, downscript, vhostfdname, - vnet_hdr, fd, &err); - if (err) { - error_propagate(errp, err); + ret =3D net_init_tap_one(tap, peer, "bridge", name, ifname, + script, downscript, vhostfdname, + vnet_hdr, fd, errp); + if (ret < 0) { close(fd); return -1; } @@ -997,12 +993,11 @@ free_fail: } } =20 - net_init_tap_one(tap, peer, "tap", name, ifname, - i >=3D 1 ? "no" : script, - i >=3D 1 ? "no" : downscript, - vhostfdname, vnet_hdr, fd, &err); - if (err) { - error_propagate(errp, err); + ret =3D net_init_tap_one(tap, peer, "tap", name, ifname, + i >=3D 1 ? "no" : script, + i >=3D 1 ? "no" : downscript, + vhostfdname, vnet_hdr, fd, errp); + if (ret < 0) { close(fd); return -1; } --=20 2.48.1