From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756833Ab2HOTva (ORCPT ); Wed, 15 Aug 2012 15:51:30 -0400 Received: from mail.windriver.com ([147.11.1.11]:36926 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756597Ab2HOTvU (ORCPT ); Wed, 15 Aug 2012 15:51:20 -0400 From: Paul Gortmaker To: , CC: Richard Weinberger , Paul Gortmaker Subject: [v2.6.34-stable 096/165] um: fix ubd cow size Date: Wed, 15 Aug 2012 15:47:20 -0400 Message-ID: <1345060109-9187-97-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.12.rc2 In-Reply-To: <1345060109-9187-1-git-send-email-paul.gortmaker@windriver.com> References: <1345060109-9187-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Richard Weinberger ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 8535639810e578960233ad39def3ac2157b0c3ec upstream. ubd_file_size() cannot use ubd_dev->cow.file because at this time ubd_dev->cow.file is not initialized. Therefore, ubd_file_size() will always report a wrong disk size when COW files are used. Reading from /dev/ubd* would crash the kernel. We have to read the correct disk size from the COW file's backing file. Signed-off-by: Richard Weinberger Signed-off-by: Paul Gortmaker --- arch/um/drivers/ubd_kern.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 3d63b83..1cbad01 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -511,8 +511,37 @@ __uml_exitcall(kill_io_thread); static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) { char *file; + int fd; + int err; + + __u32 version; + __u32 align; + char *backing_file; + time_t mtime; + unsigned long long size; + int sector_size; + int bitmap_offset; + + if (ubd_dev->file && ubd_dev->cow.file) { + file = ubd_dev->cow.file; + + goto out; + } - file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; + fd = os_open_file(ubd_dev->file, global_openflags, 0); + if (fd < 0) + return fd; + + err = read_cow_header(file_reader, &fd, &version, &backing_file, \ + &mtime, &size, §or_size, &align, &bitmap_offset); + os_close_file(fd); + + if(err == -EINVAL) + file = ubd_dev->file; + else + file = backing_file; + +out: return os_file_size(file, size_out); } -- 1.7.12.rc2