From nobody Tue Feb 10 23:33:41 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=yandex-team.ru Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 163664554863536.95815101155608; Thu, 11 Nov 2021 07:45:48 -0800 (PST) Received: from localhost ([::1]:55870 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mlCGo-0007dP-Uh for importer@patchew.org; Thu, 11 Nov 2021 10:45:46 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40582) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mlC5g-0004Yo-9o; Thu, 11 Nov 2021 10:34:16 -0500 Received: from forwardcorp1p.mail.yandex.net ([77.88.29.217]:40774) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mlC5W-00042E-Uo; Thu, 11 Nov 2021 10:34:16 -0500 Received: from iva8-d2cd82b7433e.qloud-c.yandex.net (iva8-d2cd82b7433e.qloud-c.yandex.net [IPv6:2a02:6b8:c0c:a88e:0:640:d2cd:82b7]) by forwardcorp1p.mail.yandex.net (Yandex) with ESMTP id 4555D2E0B06; Thu, 11 Nov 2021 18:34:01 +0300 (MSK) Received: from iva8-3a65cceff156.qloud-c.yandex.net (iva8-3a65cceff156.qloud-c.yandex.net [2a02:6b8:c0c:2d80:0:640:3a65:ccef]) by iva8-d2cd82b7433e.qloud-c.yandex.net (mxbackcorp/Yandex) with ESMTP id miw3MvrZto-Y0saDCOq; Thu, 11 Nov 2021 18:34:01 +0300 Received: from rvkaganb.lan (dynamic-vpn.dhcp.yndx.net [2a02:6b8:b081:8830::1:2d]) by iva8-3a65cceff156.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPS id WgGv8YbvMJ-Y0wCBM5o; Thu, 11 Nov 2021 18:34:00 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) Precedence: bulk DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1636644841; bh=DKCjFbwJQZiORGOk94Gym4SRfIr2B0CaMzsUkKErozw=; h=In-Reply-To:Message-Id:References:Date:Subject:To:From:Cc; b=V3WNhir/pgLs8qMdlR2HaLOo0zWHUu1P3VVcWOBvxRNUkNt/V4+6sA4/z8hn9PCtd DJREBi1SNx3aO9Lvrz1HaqLwWdpnuVjjzMwTphZcxUDb9S1S/YXbIai0ypQnNYvN4T wZL3Dyg4QkK+GwmtJ6tFAu1wamV2VThclPrprjXc= Authentication-Results: iva8-d2cd82b7433e.qloud-c.yandex.net; dkim=pass header.i=@yandex-team.ru X-Yandex-Fwd: 2 From: Roman Kagan To: qemu-devel@nongnu.org Subject: [PATCH 04/10] chardev/char-fe: don't allow EAGAIN from blocking read Date: Thu, 11 Nov 2021 18:33:48 +0300 Message-Id: <20211111153354.18807-5-rvkagan@yandex-team.ru> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211111153354.18807-1-rvkagan@yandex-team.ru> References: <20211111153354.18807-1-rvkagan@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=77.88.29.217; envelope-from=rvkagan@yandex-team.ru; helo=forwardcorp1p.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, SPF_HELO_NONE=0.001, T_SPF_TEMPERROR=0.01 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: , Cc: Kevin Wolf , qemu-block@nongnu.org, "Michael S. Tsirkin" , Raphael Norwitz , Hanna Reitz , yc-core@yandex-team.ru, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1636645549874100001 Content-Type: text/plain; charset="utf-8" As its name suggests, ChardevClass.chr_sync_read is supposed to do a blocking read. The only implementation of it, tcp_chr_sync_read, does set the underlying io channel to the blocking mode indeed. Therefore a failure return with EAGAIN is not expected from this call. So do not retry it in qemu_chr_fe_read_all; instead place an assertion that it doesn't fail with EAGAIN. Signed-off-by: Roman Kagan --- chardev/char-fe.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/chardev/char-fe.c b/chardev/char-fe.c index 7789f7be9c..f94efe928e 100644 --- a/chardev/char-fe.c +++ b/chardev/char-fe.c @@ -68,13 +68,10 @@ int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf,= int len) } =20 while (offset < len) { - retry: res =3D CHARDEV_GET_CLASS(s)->chr_sync_read(s, buf + offset, len - offset); - if (res =3D=3D -1 && errno =3D=3D EAGAIN) { - g_usleep(100); - goto retry; - } + /* ->chr_sync_read should block */ + assert(!(res < 0 && errno =3D=3D EAGAIN)); =20 if (res =3D=3D 0) { break; --=20 2.33.1