From patchwork Tue Oct 21 14:03:03 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Roger_Pau_Monn=C3=A9?= X-Patchwork-Id: 401507 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id DBAD114007F for ; Wed, 22 Oct 2014 01:03:51 +1100 (AEDT) Received: from localhost ([::1]:50638 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xga2M-0001c9-Os for incoming@patchwork.ozlabs.org; Tue, 21 Oct 2014 10:03:46 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41960) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xga21-0001Jw-An for qemu-devel@nongnu.org; Tue, 21 Oct 2014 10:03:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xga1w-0008PT-G2 for qemu-devel@nongnu.org; Tue, 21 Oct 2014 10:03:25 -0400 Received: from smtp.citrix.com ([66.165.176.89]:25002) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xga1w-0008Op-8D for qemu-devel@nongnu.org; Tue, 21 Oct 2014 10:03:20 -0400 X-IronPort-AV: E=Sophos;i="5.04,762,1406592000"; d="scan'208";a="183398465" From: Roger Pau Monne To: Date: Tue, 21 Oct 2014 16:03:03 +0200 Message-ID: <1413900183-28617-1-git-send-email-roger.pau@citrix.com> X-Mailer: git-send-email 1.9.3 (Apple Git-50) MIME-Version: 1.0 X-DLP: MIA2 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 66.165.176.89 Cc: Kevin Wolf , Stefan Hajnoczi , Roger Pau Monne Subject: [Qemu-devel] [PATCH v3] block: char devices on FreeBSD are not behind a pager 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 Introduce a new flag to mark devices that require requests to be aligned and replace the usage of BDRV_O_NOCACHE and O_DIRECT with this flag when appropriate. If a character device is used as a backend on a FreeBSD host set this flag unconditionally. Signed-off-by: Roger Pau Monné Reviewed-by: Max Reitz Cc: Kevin Wolf Cc: Stefan Hajnoczi --- Changes since v2: - s/alignement/alignment/. - Don't make needs_alignment a bit field. - Add braces to single statement conditional block. Changes since v1: - Intead of appending BDRV_O_NOCACHE and O_DIRECT when a char dev is used on FreeBSD introduce a new flag that is used to mark if a device needs requests to be aligned. --- block/raw-posix.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/block/raw-posix.c b/block/raw-posix.c index 86ce4f2..afa4b01 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -150,6 +150,7 @@ typedef struct BDRVRawState { bool has_discard:1; bool has_write_zeroes:1; bool discard_zeroes:1; + bool needs_alignment; #ifdef CONFIG_FIEMAP bool skip_fiemap; #endif @@ -230,7 +231,7 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp) /* For /dev/sg devices the alignment is not really used. With buffered I/O, we don't have any restrictions. */ - if (bs->sg || !(s->open_flags & O_DIRECT)) { + if (bs->sg || !s->needs_alignment) { bs->request_alignment = 1; s->buf_align = 1; return; @@ -446,6 +447,9 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->has_discard = true; s->has_write_zeroes = true; + if ((bs->open_flags & BDRV_O_NOCACHE) != 0) { + s->needs_alignment = true; + } if (fstat(s->fd, &st) < 0) { error_setg_errno(errp, errno, "Could not stat file"); @@ -472,6 +476,17 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, } #endif } +#ifdef __FreeBSD__ + if (S_ISCHR(st.st_mode)) { + /* + * The file is a char device (disk), which on FreeBSD isn't behind + * a pager, so force all requests to be aligned. This is needed + * so QEMU makes sure all IO operations on the device are aligned + * to sector size, or else FreeBSD will reject them with EINVAL. + */ + s->needs_alignment = true; + } +#endif #ifdef CONFIG_XFS if (platform_test_xfs_fd(s->fd)) { @@ -1076,11 +1091,12 @@ static BlockDriverAIOCB *raw_aio_submit(BlockDriverState *bs, return NULL; /* - * If O_DIRECT is used the buffer needs to be aligned on a sector - * boundary. Check if this is the case or tell the low-level - * driver that it needs to copy the buffer. + * Check if the underlying device requires requests to be aligned, + * and if the request we are trying to submit is aligned or not. + * If this is the case tell the low-level driver that it needs + * to copy the buffer. */ - if ((bs->open_flags & BDRV_O_NOCACHE)) { + if (s->needs_alignment) { if (!bdrv_qiov_is_aligned(bs, qiov)) { type |= QEMU_AIO_MISALIGNED; #ifdef CONFIG_LINUX_AIO