From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: [PATCH 3/3] kvmtool/run: do not overwrite /virt/init Date: Thu, 22 Oct 2015 17:59:45 +0200 Message-ID: <20151022155945.GA15555@redhat.com> References: <20151022155921.GA15527@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Andre Przywara , Aneesh Kumar , Sasha Levin , Pekka Enberg , Will Deacon Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36822 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250AbbJVQDT (ORCPT ); Thu, 22 Oct 2015 12:03:19 -0400 Content-Disposition: inline In-Reply-To: <20151022155921.GA15527@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: To me kvm_setup_guest_init() behaviour looks "obviously wrong" and unfriendly because it always overwrites /virt/init. kvm_setup_guest_init() is also called when we are going to use this tree as a rootfs, and without another patch ("kvmtool/run: append cfg.kernel_cmdline at the end of real_cmdline") the user can't use "lkvm run -p init=my_init_path". This simply means that you can not use a customized init unless you patch kvmtool. Change extract_file() to do nothing if the file already exists. This should not affect do_setup() which calls kvm_setup_guest_init() only if make_dir(guestfs_name) creates the new/empty dir. Signed-off-by: Oleg Nesterov --- builtin-setup.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/builtin-setup.c b/builtin-setup.c index 1e5b1e4..8be8d62 100644 --- a/builtin-setup.c +++ b/builtin-setup.c @@ -130,10 +130,14 @@ static int extract_file(const char *guestfs_name, const char *filename, snprintf(path, PATH_MAX, "%s%s/%s", kvm__get_dir(), guestfs_name, filename); - remove(path); - fd = open(path, O_CREAT | O_WRONLY, 0755); - if (fd < 0) + + fd = open(path, O_EXCL | O_CREAT | O_WRONLY, 0755); + if (fd < 0) { + if (errno == EEXIST) + return 0; die("Fail to setup %s", path); + } + ret = xwrite(fd, data, (size_t)_size); if (ret < 0) die("Fail to setup %s", path); -- 2.4.3