From mboxrd@z Thu Jan 1 00:00:00 1970 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 E6D12C48BC3 for ; Wed, 21 Feb 2024 15:26:35 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rcoTc-0006ke-JK; Wed, 21 Feb 2024 10:25:42 -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 <140110d514572af87a86ab169323528b3ca9c94d@lizzy.crudebyte.com>) id 1rcoMq-0003Rf-OZ for qemu-devel@nongnu.org; Wed, 21 Feb 2024 10:18:41 -0500 Received: from lizzy.crudebyte.com ([91.194.90.13]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <140110d514572af87a86ab169323528b3ca9c94d@lizzy.crudebyte.com>) id 1rco8C-0000Be-UU for qemu-devel@nongnu.org; Wed, 21 Feb 2024 10:03:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=lizzy; h=Message-Id:Cc:To:Subject:Date:From:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Content-ID: Content-Description; bh=y3KE/x9cBngz6SsDzZE4IUFJApU3YzKsgNydsU8Xl+c=; b=NCG+J vuSaCgzHZ0CzGAg2U9bOfyE8LfpdQvBoF0y02qRx63nFUn80FWz6xhS9k0X8QjzgCYSm39i5Ixyfj i9q4rpzTNXdCE8OUTGokwhMvR/klRa/IQF+44g++OZFkJBZyVcTvQ3fplTsPGi8Z+AvgsyCBh6f+m OoXNqdTzraVcMsG74eSM2X/CbeJHiLDu5FDd41JvDH6BBqGZy3almmMuW+MWKVGsYVV3hY33EZK3O oWaOIeh5GBri78sAOd1dUzhxC+Mw4xy56bOhg6LmSgOkVhE/J9nUWM4+/fxVBSa0UtxvDaxBGyRo4 DQcrwfJVB1uRbwsdiKnGsqZOwvhsw==; From: Christian Schoenebeck Date: Wed, 21 Feb 2024 15:13:13 +0100 Subject: [PATCH 1/1] tests/9p: add 'use-after-unlink' test To: qemu-devel@nongnu.org Cc: Greg Kurz Message-Id: Received-SPF: none client-ip=91.194.90.13; envelope-from=140110d514572af87a86ab169323528b3ca9c94d@lizzy.crudebyte.com; helo=lizzy.crudebyte.com 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, SPF_NONE=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 After removing a file from the file system, we should still be able to do I/O on the file if we already had it open before removal. Signed-off-by: Christian Schoenebeck --- OK, this was a bit surprising to me. I was expecting this test to fail, but it works! tests/qtest/virtio-9p-test.c | 41 ++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c index 65e69491e5..7638c0a183 100644 --- a/tests/qtest/virtio-9p-test.c +++ b/tests/qtest/virtio-9p-test.c @@ -693,6 +693,45 @@ static void fs_unlinkat_hardlink(void *obj, void *data, g_assert(stat(real_file, &st_real) == 0); } +static void fs_use_after_unlink(void *obj, void *data, + QGuestAllocator *t_alloc) +{ + QVirtio9P *v9p = obj; + v9fs_set_allocator(t_alloc); + static const uint32_t write_count = P9_MAX_SIZE / 2; + g_autofree char *real_file = virtio_9p_test_path("09/doa_file"); + g_autofree char *buf = g_malloc0(write_count); + struct stat st_file; + uint32_t fid_file; + uint32_t count; + + tattach({ .client = v9p }); + + /* create a file "09/doa_file" and make sure it exists and is regular */ + tmkdir({ .client = v9p, .atPath = "/", .name = "09" }); + tlcreate({ .client = v9p, .atPath = "09", .name = "doa_file" }); + g_assert(stat(real_file, &st_file) == 0); + g_assert((st_file.st_mode & S_IFMT) == S_IFREG); + + /* request a FID for that regular file that we can work with next */ + fid_file = twalk({ + .client = v9p, .fid = 0, .path = "09/doa_file" + }).newfid; + g_assert(fid_file != 0); + + /* now first open the file in write mode before ... */ + tlopen({ .client = v9p, .fid = fid_file, .flags = O_WRONLY }); + /* ... removing the file from file system */ + tunlinkat({ .client = v9p, .atPath = "09", .name = "doa_file" }); + + /* file is removed, but we still have it open, so this should succeed */ + count = twrite({ + .client = v9p, .fid = fid_file, .offset = 0, .count = write_count, + .data = buf + }).count; + g_assert_cmpint(count, ==, write_count); +} + static void *assign_9p_local_driver(GString *cmd_line, void *arg) { virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr"); @@ -756,6 +795,8 @@ static void register_virtio_9p_test(void) qos_add_test("local/hardlink_file", "virtio-9p", fs_hardlink_file, &opts); qos_add_test("local/unlinkat_hardlink", "virtio-9p", fs_unlinkat_hardlink, &opts); + qos_add_test("local/use_after_unlink", "virtio-9p", fs_use_after_unlink, + &opts); } libqos_init(register_virtio_9p_test); -- 2.30.2