From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58845) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bUS2X-0003WZ-Bv for qemu-devel@nongnu.org; Tue, 02 Aug 2016 01:14:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bUS2V-0003gu-D6 for qemu-devel@nongnu.org; Tue, 02 Aug 2016 01:14:52 -0400 Received: from qemu.weilnetz.de ([2a03:4000:2:362::1]:47380) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bUS2V-0003gn-6i for qemu-devel@nongnu.org; Tue, 02 Aug 2016 01:14:51 -0400 From: Stefan Weil Date: Tue, 2 Aug 2016 07:14:37 +0200 Message-Id: <1470114877-1466-1-git-send-email-sw@weilnetz.de> Subject: [Qemu-devel] [PATCH v2 for-2.7] wxx: Fix handling of files used for character devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: QEMU Developer Cc: Peter Maydell , Paolo Bonzini , Benjamin David Lunt , Stefan Weil On Windows, such files were not truncated like on all other hosts. Now we also test whether truncation is needed when running on Windows. The append case was also incorrect because it needs a different value for the desired access mode. Reported-by: Benjamin David Lunt Signed-off-by: Stefan Weil --- This patch supersedes my previous patch for qemu-char which only fixed the truncate case. Paolo gave the hint to the wrong access mode (see also commit 52074d0f662fc51293d4cde8077631f754784405). Regards Stefan qemu-char.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/qemu-char.c b/qemu-char.c index e4b8448..e7d3399 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -4197,14 +4197,26 @@ static CharDriverState *qmp_chardev_open_file(const char *id, ChardevFile *file = backend->u.file.data; ChardevCommon *common = qapi_ChardevFile_base(file); HANDLE out; + DWORD accessmode; + DWORD flags; if (file->has_in) { error_setg(errp, "input file not supported"); return NULL; } - out = CreateFile(file->out, GENERIC_WRITE, FILE_SHARE_READ, NULL, - OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); + if (file->has_append && file->append) { + /* Append to file if it already exists. */ + accessmode = FILE_GENERIC_WRITE & ~FILE_WRITE_DATA; + flags = OPEN_ALWAYS; + } else { + /* Truncate file if it already exists. */ + accessmode = GENERIC_WRITE; + flags = CREATE_ALWAYS; + } + + out = CreateFile(file->out, accessmode, FILE_SHARE_READ, NULL, flags, + FILE_ATTRIBUTE_NORMAL, NULL); if (out == INVALID_HANDLE_VALUE) { error_setg(errp, "open %s failed", file->out); return NULL; -- 2.1.4