From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from akranes.kaiser.cx (akranes.kaiser.cx [152.53.16.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 23E1512F586; Mon, 26 Feb 2024 19:29:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=152.53.16.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708975783; cv=none; b=gw5rrnjeh6+picChpEVaxjWq7KSh6Hff5IrAu4JxxqLxn01+GV1iyt/+5AhumuXJHBelq7jX6OGd4jZxXMKSi/oigfvoTl6lNYq8igdvvyZu3wS4FYwlMsQ1fgWEn8EcNqyusAuGCruMfWdBgGoPebb3ed3ZOuHakPME24GUr6s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708975783; c=relaxed/simple; bh=Zs+IbvV7d0hitWb7oIpv8aJWVlfPLjA5xRa5/SeXvWc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=B7gQO/rFpdVByFFaC5eTkm4KUslstZeD1XqdpX4hba7a2EbIxbdfNKiKljbVZGDU25EMIXToXRBlhTB7eM2tPVKBgUgFuTnTKfubac5J0lDbTFmtvygEcD+DIQBzI1KamihTFLlB2U3xLQ8bQvecPk6nw4sCYKSNrTBKNP8VMpc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kaiser.cx; spf=pass smtp.mailfrom=kaiser.cx; arc=none smtp.client-ip=152.53.16.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kaiser.cx Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kaiser.cx Received: from dslb-188-097-209-155.188.097.pools.vodafone-ip.de ([188.97.209.155] helo=martin-debian-2.paytec.ch) by akranes.kaiser.cx with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1regey-001hI7-11; Mon, 26 Feb 2024 20:29:08 +0100 From: Martin Kaiser To: Trond Myklebust , Anna Schumaker , David Howells Cc: Chuck Lever , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Kaiser Subject: [PATCH v2] nfs: keep server info for remounts Date: Mon, 26 Feb 2024 20:29:08 +0100 Message-Id: <20240226192908.48789-1-martin@kaiser.cx> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit With newer kernels that use fs_context for nfs mounts, remounts fail with -EINVAL. $ mount -t nfs -o nolock 10.0.0.1:/tmp/test /mnt/test/ $ mount -t nfs -o remount /mnt/test/ mount: mounting 10.0.0.1:/tmp/test on /mnt/test failed: Invalid argument For remounts, the nfs server address and port are populated by nfs_init_fs_context and later overwritten with 0x00 bytes by nfs23_parse_monolithic. The remount then fails as the server address is invalid. Fix this by not overwriting nfs server info in nfs23_parse_monolithic if we're doing a remount. Fixes: f2aedb713c28 ("NFS: Add fs_context support.") Signed-off-by: Martin Kaiser --- v2: - rebased against today's linux-next Dear all, I'm resending this patch, it might have slipped through the cracks. The problem that I'm trying to fix is still present in linux-next. Thanks in advance for any reviews and comments. I guess that we're taking this path for remounts do_remount fs_context_for_reconfigure alloc_fs_context init_fs_context == nfs_init_fs_context fc->root is set for remounts ctx->nfs_server is populated parse_monolithic_mount_data nfs_fs_context_parse_monolithic nfs23_parse_monolithic ctx->nfs_server is overwritten with data from mount request An alternative to checking for !is_remount_fc(fc) would be to check if (ctx->nfs_server.addrlen == 0) fs/nfs/fs_context.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c index 853e8d609bb3..41126d6dcd76 100644 --- a/fs/nfs/fs_context.c +++ b/fs/nfs/fs_context.c @@ -1111,9 +1111,12 @@ static int nfs23_parse_monolithic(struct fs_context *fc, ctx->acdirmax = data->acdirmax; ctx->need_mount = false; - memcpy(sap, &data->addr, sizeof(data->addr)); - ctx->nfs_server.addrlen = sizeof(data->addr); - ctx->nfs_server.port = ntohs(data->addr.sin_port); + if (!is_remount_fc(fc)) { + memcpy(sap, &data->addr, sizeof(data->addr)); + ctx->nfs_server.addrlen = sizeof(data->addr); + ctx->nfs_server.port = ntohs(data->addr.sin_port); + } + if (sap->ss_family != AF_INET || !nfs_verify_server_address(sap)) goto out_no_address; -- 2.39.2