From patchwork Thu Apr 15 12:43:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 1466620 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=H7y52BUT; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4FLfD34xQqz9sRR for ; Thu, 15 Apr 2021 22:44:03 +1000 (AEST) Received: from localhost ([::1]:58596 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lX1Ll-0008MC-Ae for incoming@patchwork.ozlabs.org; Thu, 15 Apr 2021 08:44:01 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50204) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lX1L1-0008Jk-2A; Thu, 15 Apr 2021 08:43:15 -0400 Received: from mail-ej1-x630.google.com ([2a00:1450:4864:20::630]:34353) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lX1Kz-0006Tp-J1; Thu, 15 Apr 2021 08:43:14 -0400 Received: by mail-ej1-x630.google.com with SMTP id x12so15871066ejc.1; Thu, 15 Apr 2021 05:43:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=WD7MCmHJ/D46aRVbFpWL4Rq/RVjBhO+w4A8zwh3SmEg=; b=H7y52BUTZKL/zlY4ydQLe+mtwv09pdJ9RzcvjSeog2KMSCcMonbmCQHcLPwajP/okO eqs+aQIaztamMNbzFAnpsOhn0+QCe0FUgnC0C5W6J93Iaka8Gk5FWa4EH4Xm81ai0zJ0 UbL/arf0dL/ZVqifl2Vgw/+JwnMpwU0HpJySWeqvFkZ3D+Wb8+SWJvLvNuIIwjDPJfEP 0zjVz/v0QnciXP1dhAl9M77tn7UEQ2GM2tMB8eRkIHx/pa0ngSxtLgqhjGVjdLfbjcno LxO87e/4LRC72DWwUuaQZMtpJEOpkN4bczPxZiEYSrJ4U7D73CZDmsUHyZpYMUaFqrGF /KVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=WD7MCmHJ/D46aRVbFpWL4Rq/RVjBhO+w4A8zwh3SmEg=; b=NKuhxOPAtGrY7/XlAjiwxQh1Z16ERrgaDSfeexTppSekfY2AirqJ+WRBAHHyt0lqlb 4Jo/W6OFcD18afa9PsNNoaDdYzYsJ5xBBIMpd4H1rAIvt0r5W1Br0ApCank7YTcPnxcV lAdelZRGynpnNVNG3kGtyVYX55L/8FWTMAZ0qsHSuykvPrli3iZG1KK86KSfEwlpRkJi bi1siQnBI7OAhX1BcatwQdNsSiAgy6CLtr9KtwkSRqwiIenXY8jTv6Spg4HL74h3VOdS d8H/iaeJgNB258cgbnBZrPbU7d328lXdlMqFpe3wh6dCPcTYnKyXpA8/zxEeUdhtk+sz p7kw== X-Gm-Message-State: AOAM533TBYvmxyW6O6NUee++IXybZJkrBDYzRGj67tfeT4cxsjYZtwZC vmGFf6AsNMeqDgq3Ydv1tH06bcwVZKY= X-Google-Smtp-Source: ABdhPJyC9R3+JmR9ukPRLN1IMXrvulEkKEZYc2I0Fwlaw3f4OZBQ1S1rMiP/9aZtjeR6Dg7ST0PSbQ== X-Received: by 2002:a17:906:814d:: with SMTP id z13mr3145652ejw.479.1618490591778; Thu, 15 Apr 2021 05:43:11 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:5e2c:eb9a:a8b6:fd3e]) by smtp.gmail.com with ESMTPSA id r10sm1862585ejd.112.2021.04.15.05.43.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Apr 2021 05:43:11 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PATCH 3/3] file-posix: fix max_iov for /dev/sg devices Date: Thu, 15 Apr 2021 14:43:07 +0200 Message-Id: <20210415124307.428203-4-pbonzini@redhat.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210415124307.428203-1-pbonzini@redhat.com> References: <20210415124307.428203-1-pbonzini@redhat.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::630; envelope-from=paolo.bonzini@gmail.com; helo=mail-ej1-x630.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: fam@euphon.net, qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Even though it was only called for devices that have bs->sg set (which must be character devices), sg_get_max_segments looked at /sys/dev/block which only works for block devices. On Linux the sg driver has its own way to provide the maximum number of iovecs in a scatter/gather list. --- block/file-posix.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block/file-posix.c b/block/file-posix.c index e37a6bb8de..b348b37ccb 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1198,6 +1198,17 @@ static int sg_get_max_segments(int fd, struct stat *st) int sysfd = -1; long max_segments; + if (S_ISCHR(st->st_mode)) { + if (ioctl(fd, SG_GET_SG_TABLESIZE, &ret) == 0) { + return ret; + } + return -EIO; + } + + if (!S_ISBLK(st->st_mode)) { + return -ENOTSUP; + } + sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/max_segments", major(st->st_rdev), minor(st->st_rdev)); sysfd = open(sysfspath, O_RDONLY);