From patchwork Mon Jan 27 20:24:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13952209 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 57C7EC0218D for ; Tue, 28 Jan 2025 08:19:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tcgY3-0004fU-E6; Tue, 28 Jan 2025 03:02:15 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tcgX9-0000wA-2G; Tue, 28 Jan 2025 03:01:19 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tcgX7-0001qT-DI; Tue, 28 Jan 2025 03:01:18 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 98D2AE1B4E; Tue, 28 Jan 2025 10:57:08 +0300 (MSK) Received: from localhost.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id 149B81A6301; Tue, 28 Jan 2025 10:57:34 +0300 (MSK) Received: by localhost.tls.msk.ru (Postfix, from userid 1000) id E85C552093; Tue, 28 Jan 2025 10:57:33 +0300 (MSK) To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Jakub Jelen , "Richard W . M . Jones" , Kevin Wolf , Michael Tokarev Subject: [Stable-9.1.3 07/58] ssh: Do not switch session to non-blocking mode Date: Mon, 27 Jan 2025 23:24:53 +0300 Message-Id: <20250127202547.3723716-7-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 From: Michael Tokarev Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -53 X-Spam_score: -5.4 X-Spam_bar: ----- X-Spam_report: (-5.4 / 5.0 requ) BAYES_00=-1.9, DATE_IN_PAST_06_12=1.543, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The libssh does not handle non-blocking mode in SFTP correctly. The driver code already changes the mode to blocking for the SFTP initialization, but for some reason changes to non-blocking mode. This used to work accidentally until libssh in 0.11 branch merged the patch to avoid infinite looping in case of network errors: https://gitlab.com/libssh/libssh-mirror/-/merge_requests/498 Since then, the ssh driver in qemu fails to read files over SFTP as the first SFTP messages exchanged after switching the session to non-blocking mode return SSH_AGAIN, but that message is lost int the SFTP internals and interpretted as SSH_ERROR, which is returned to the caller: https://gitlab.com/libssh/libssh-mirror/-/issues/280 This is indeed an issue in libssh that we should address in the long term, but it will require more work on the internals. For now, the SFTP is not supported in non-blocking mode. Fixes: https://gitlab.com/libssh/libssh-mirror/-/issues/280 Signed-off-by: Jakub Jelen Signed-off-by: Richard W.M. Jones Message-ID: <20241113125526.2495731-1-rjones@redhat.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf (cherry picked from commit fbdea3d6c13d5a75895c287a004c6f1a6bf6c164) Signed-off-by: Michael Tokarev diff --git a/block/ssh.c b/block/ssh.c index 27d582e0e3..5c16ff4fb6 100644 --- a/block/ssh.c +++ b/block/ssh.c @@ -865,9 +865,6 @@ static int ssh_open(BlockDriverState *bs, QDict *options, int bdrv_flags, goto err; } - /* Go non-blocking. */ - ssh_set_blocking(s->session, 0); - if (s->attrs->type == SSH_FILEXFER_TYPE_REGULAR) { bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; }