From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36661) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zotal-0001im-IS for qemu-devel@nongnu.org; Wed, 21 Oct 2015 09:38:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zotaf-0005Pl-Ui for qemu-devel@nongnu.org; Wed, 21 Oct 2015 09:38:11 -0400 Date: Wed, 21 Oct 2015 15:37:55 +0200 From: Kevin Wolf Message-ID: <20151021133755.GA3962@noname.redhat.com> References: <1445393209-26545-1-git-send-email-famz@redhat.com> <1445393209-26545-10-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1445393209-26545-10-git-send-email-famz@redhat.com> Subject: Re: [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: Fam Zheng Cc: pbonzini@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org Am 21.10.2015 um 04:06 hat Fam Zheng geschrieben: > 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); The blk_is_available() check must come first, otherwise we can call bdrv_drained_begin(NULL) and bdrv_drained_begin() doesn't accept that. Kevin