From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52781) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zoioa-0003g9-Vd for qemu-devel@nongnu.org; Tue, 20 Oct 2015 22:07:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zoioa-00042I-4d for qemu-devel@nongnu.org; Tue, 20 Oct 2015 22:07:44 -0400 From: Fam Zheng Date: Wed, 21 Oct 2015 10:06:46 +0800 Message-Id: <1445393209-26545-10-git-send-email-famz@redhat.com> In-Reply-To: <1445393209-26545-1-git-send-email-famz@redhat.com> References: <1445393209-26545-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v5 09/12] block: Add "drained begin/end" for internal snapshot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, qemu-block@nongnu.org This ensures the atomicity of the transaction by avoiding processing of external requests such as those from ioeventfd. state->bs is assigned right after bdrv_drained_begin. Because it was used as the flag for deletion or not in abort, now we need a separate flag - InternalSnapshotState.created. Signed-off-by: Fam Zheng --- blockdev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/blockdev.c b/blockdev.c index 52f44b2..92c2d0d 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1370,6 +1370,7 @@ typedef struct InternalSnapshotState { BlockDriverState *bs; AioContext *aio_context; QEMUSnapshotInfo sn; + bool created; } InternalSnapshotState; static void internal_snapshot_prepare(BlkTransactionState *common, @@ -1407,6 +1408,8 @@ static void internal_snapshot_prepare(BlkTransactionState *common, /* AioContext is released in .clean() */ state->aio_context = blk_get_aio_context(blk); aio_context_acquire(state->aio_context); + state->bs = blk_bs(blk); + bdrv_drained_begin(state->bs); if (!blk_is_available(blk)) { error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); @@ -1465,7 +1468,7 @@ static void internal_snapshot_prepare(BlkTransactionState *common, } /* 4. succeed, mark a snapshot is created */ - state->bs = bs; + state->created = true; } static void internal_snapshot_abort(BlkTransactionState *common) @@ -1476,7 +1479,7 @@ static void internal_snapshot_abort(BlkTransactionState *common) QEMUSnapshotInfo *sn = &state->sn; Error *local_error = NULL; - if (!bs) { + if (!state->created) { return; } @@ -1497,6 +1500,7 @@ static void internal_snapshot_clean(BlkTransactionState *common) common, common); if (state->aio_context) { + bdrv_drained_end(state->bs); aio_context_release(state->aio_context); } } -- 2.4.3