From patchwork Wed Jan 16 16:24:38 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Beno=C3=AEt_Canet?= X-Patchwork-Id: 212802 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 7CFB72C0084 for ; Thu, 17 Jan 2013 03:26:55 +1100 (EST) Received: from localhost ([::1]:33917 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvVpF-0002I4-3t for incoming@patchwork.ozlabs.org; Wed, 16 Jan 2013 11:26:53 -0500 Received: from eggs.gnu.org ([208.118.235.92]:41247) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvVoy-0002F1-Oe for qemu-devel@nongnu.org; Wed, 16 Jan 2013 11:26:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TvVow-00078Q-4h for qemu-devel@nongnu.org; Wed, 16 Jan 2013 11:26:36 -0500 Received: from nodalink.pck.nerim.net ([62.212.105.220]:43230 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvVov-000787-E3 for qemu-devel@nongnu.org; Wed, 16 Jan 2013 11:26:33 -0500 Received: by paradis.irqsave.net (Postfix, from userid 1002) id E9D7D874325; Wed, 16 Jan 2013 17:58:09 +0100 (CET) Received: from localhost.localdomain (unknown [192.168.77.1]) by paradis.irqsave.net (Postfix) with ESMTP id 8747787432A; Wed, 16 Jan 2013 17:56:04 +0100 (CET) From: =?UTF-8?q?Beno=C3=AEt=20Canet?= To: qemu-devel@nongnu.org Date: Wed, 16 Jan 2013 17:24:38 +0100 Message-Id: <1358353497-5292-18-git-send-email-benoit@irqsave.net> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1358353497-5292-1-git-send-email-benoit@irqsave.net> References: <1358353497-5292-1-git-send-email-benoit@irqsave.net> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 62.212.105.220 Cc: kwolf@redhat.com, pbonzini@redhat.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= , stefanha@redhat.com Subject: [Qemu-devel] [RFC V5 17/36] qcow2: Extract qcow2_add_feature and qcow2_remove_feature. 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 Signed-off-by: Benoit Canet --- block/qcow2.c | 49 ++++++++++++++++++++++++++++++------------------- block/qcow2.h | 4 ++-- 2 files changed, 32 insertions(+), 21 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index b8c4e31..f046a77 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -238,61 +238,72 @@ static void report_unsupported_feature(BlockDriverState *bs, } /* - * Sets the dirty bit and flushes afterwards if necessary. + * Sets the an incompatible feature bit and flushes afterwards if necessary. * * The incompatible_features bit is only set if the image file header was * updated successfully. Therefore it is not required to check the return * value of this function. */ -int qcow2_mark_dirty(BlockDriverState *bs) +static int qcow2_add_feature(BlockDriverState *bs, + QCow2IncompatibleFeature feature) { BDRVQcowState *s = bs->opaque; uint64_t val; - int ret; + int ret = 0; assert(s->qcow_version >= 3); - if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { - return 0; /* already dirty */ + if (s->incompatible_features & feature) { + return 0; /* already added */ } - val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); + val = cpu_to_be64(s->incompatible_features | feature); ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), &val, sizeof(val)); if (ret < 0) { return ret; } - ret = bdrv_flush(bs->file); - if (ret < 0) { - return ret; - } - /* Only treat image as dirty if the header was updated successfully */ - s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; + /* Only treat image as having the feature if the header was updated + * successfully + */ + s->incompatible_features |= feature; return 0; } +int qcow2_mark_dirty(BlockDriverState *bs) +{ + return qcow2_add_feature(bs, QCOW2_INCOMPAT_DIRTY); +} + /* - * Clears the dirty bit and flushes before if necessary. Only call this - * function when there are no pending requests, it does not guard against - * concurrent requests dirtying the image. + * Clears an incompatible feature bit and flushes before if necessary. + * Only call this function when there are no pending requests, it does not + * guard against concurrent requests adding a feature to the image. */ -static int qcow2_mark_clean(BlockDriverState *bs) +static int qcow2_remove_feature(BlockDriverState *bs, + QCow2IncompatibleFeature feature) { BDRVQcowState *s = bs->opaque; + int ret = 0; - if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { - int ret = bdrv_flush(bs); + if (s->incompatible_features & feature) { + ret = bdrv_flush(bs); if (ret < 0) { return ret; } - s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; + s->incompatible_features &= ~feature; return qcow2_update_header(bs); } return 0; } +static int qcow2_mark_clean(BlockDriverState *bs) +{ + return qcow2_remove_feature(bs, QCOW2_INCOMPAT_DIRTY); +} + static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result, BdrvCheckMode fix) { diff --git a/block/qcow2.h b/block/qcow2.h index b17977f..59432fd 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -170,14 +170,14 @@ enum { }; /* Incompatible feature bits */ -enum { +typedef enum { QCOW2_INCOMPAT_DIRTY_BITNR = 0, QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, QCOW2_INCOMPAT_DEDUP_BITNR = 1, QCOW2_INCOMPAT_DEDUP = 1 << QCOW2_INCOMPAT_DEDUP_BITNR, QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY | QCOW2_INCOMPAT_DEDUP, -}; +} QCow2IncompatibleFeature; /* Compatible feature bits */ enum {