From patchwork Thu Sep 20 19:13:31 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 185465 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 4A7772C0078 for ; Fri, 21 Sep 2012 05:55:02 +1000 (EST) Received: from localhost ([::1]:57042 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEmpw-000486-FG for incoming@patchwork.ozlabs.org; Thu, 20 Sep 2012 15:55:00 -0400 Received: from eggs.gnu.org ([208.118.235.92]:41430) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEmpn-00047i-Eu for qemu-devel@nongnu.org; Thu, 20 Sep 2012 15:54:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TEmpm-0006OI-4y for qemu-devel@nongnu.org; Thu, 20 Sep 2012 15:54:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44721) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEmpl-0006OA-Sw for qemu-devel@nongnu.org; Thu, 20 Sep 2012 15:54:50 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q8KJsVRs002994 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 20 Sep 2012 15:54:32 -0400 Received: from localhost (ovpn-112-41.phx2.redhat.com [10.3.112.41]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q8KJEaOC022241 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Thu, 20 Sep 2012 15:14:38 -0400 From: Jeff Cody To: qemu-devel@nongnu.org Date: Thu, 20 Sep 2012 15:13:31 -0400 Message-Id: <71de241ac2e46041abdddd36683b2a1f82fb1e2c.1348157913.git.jcody@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, pbonzini@redhat.com, eblake@redhat.com, supriyak@linux.vnet.ibm.com Subject: [Qemu-devel] [PATCH v4 15/19] block: raw-win32 driver reopen support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This is the support for reopen, for win32. Note that there is a key difference in the win32 reopen, namely that it is not guaranteed safe like all the other drivers. Attempts are made to reopen the file, or open the file in a new handle prior to closing the old handle. However, this is not always feasible, and there are times when we must close the existing file and then open the new file, breaking the transactional nature of the reopen. Signed-off-by: Jeff Cody --- block/raw-win32.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) diff --git a/block/raw-win32.c b/block/raw-win32.c index 78c8306..8a698d3 100644 --- a/block/raw-win32.c +++ b/block/raw-win32.c @@ -31,6 +31,7 @@ #define FTYPE_FILE 0 #define FTYPE_CD 1 #define FTYPE_HARDDISK 2 +#define WINDOWS_VISTA 6 typedef struct BDRVRawState { HANDLE hfile; @@ -38,6 +39,10 @@ typedef struct BDRVRawState { char drive_path[16]; /* format: "d:\" */ } BDRVRawState; +typedef struct BDRVRawReopenState { + HANDLE hfile; +} BDRVRawReopenState; + int qemu_ftruncate64(int fd, int64_t length) { LARGE_INTEGER li; @@ -117,6 +122,103 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags) return 0; } +static int raw_reopen_prepare(BDRVReopenState *state, + BlockReopenQueue *queue, Error **errp) +{ + BDRVRawState *s; + BDRVRawReopenState *raw_s; + int ret = 0; + int access_flags; + DWORD overlapped; + OSVERSIONINFO osvi; + + assert(state != NULL); + assert(state->bs != NULL); + + s = state->bs->opaque; + + state->opaque = g_malloc0(sizeof(BDRVRawReopenState)); + raw_s = state->opaque; + + raw_parse_flags(state->flags, &access_flags, &overlapped); + + ZeroMemory(&osvi, sizeof(OSVERSIONINFO)); + osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO); + + GetVersionEx(&osvi); + raw_s->hfile = INVALID_HANDLE_VALUE; + + if (osvi.dwMajorVersion >= WINDOWS_VISTA) { + raw_s->hfile = ReOpenFile(s->hfile, access_flags, FILE_SHARE_READ, + overlapped); + } + + /* could not reopen the file handle, so fall back to opening + * new file (CreateFile) */ + if (raw_s->hfile == INVALID_HANDLE_VALUE) { + raw_s->hfile = CreateFile(state->bs->filename, access_flags, + FILE_SHARE_READ, NULL, OPEN_EXISTING, + overlapped, NULL); + if (raw_s->hfile == INVALID_HANDLE_VALUE) { + /* this could happen because the access_flags requested are + * incompatible with the existing share mode of s->hfile, + * so our only option now is to close s->hfile, and try again. + * This could end badly */ + CloseHandle(s->hfile); + s->hfile = INVALID_HANDLE_VALUE; + raw_s->hfile = CreateFile(state->bs->filename, access_flags, + FILE_SHARE_READ, NULL, OPEN_EXISTING, + overlapped, NULL); + if (raw_s->hfile == INVALID_HANDLE_VALUE) { + /* Unrecoverable error */ + error_set(errp, ERROR_CLASS_GENERIC_ERROR, + "Fatal error reopening %s file; file closed and cannot be opened\n", + state->bs->filename); + ret = -1; + } else{ + /* since we had to close the original, go ahead and + * re-assign here */ + s->hfile = raw_s->hfile; + raw_s->hfile = INVALID_HANDLE_VALUE; + } + } + } + + return ret; +} + + +static void raw_reopen_commit(BDRVReopenState *state) +{ + BDRVRawReopenState *raw_s = state->opaque; + BDRVRawState *s = state->bs->opaque; + + if (raw_s->hfile != INVALID_HANDLE_VALUE) { + CloseHandle(s->hfile); + s->hfile = raw_s->hfile; + } + + g_free(state->opaque); + state->opaque = NULL; +} + + +static void raw_reopen_abort(BDRVReopenState *state) +{ + BDRVRawReopenState *raw_s = state->opaque; + + /* nothing to do if NULL, we didn't get far enough */ + if (raw_s == NULL) { + return; + } + + if (raw_s->hfile != INVALID_HANDLE_VALUE) { + CloseHandle(raw_s->hfile); + } + g_free(state->opaque); + state->opaque = NULL; +} + static int raw_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { @@ -287,6 +389,9 @@ static BlockDriver bdrv_file = { .protocol_name = "file", .instance_size = sizeof(BDRVRawState), .bdrv_file_open = raw_open, + .bdrv_reopen_prepare = raw_reopen_prepare, + .bdrv_reopen_commit = raw_reopen_commit, + .bdrv_reopen_abort = raw_reopen_abort, .bdrv_close = raw_close, .bdrv_create = raw_create,