Am 22.10.2015 um 08:32 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 <f...@redhat.com> > --- > blockdev.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index 52f44b2..adc0e69 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, > @@ -1414,6 +1415,9 @@ static void > internal_snapshot_prepare(BlkTransactionState *common, > } > bs = blk_bs(blk); > > + state->bs = bs; > + bdrv_drained_begin(bs); > + > if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) { > return; > }
More context: /* AioContext is released in .clean() */ state->aio_context = blk_get_aio_context(blk); aio_context_acquire(state->aio_context); if (!blk_is_available(blk)) { error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); return; } bs = blk_bs(blk); state->bs = bs; bdrv_drained_begin(bs); If we error out because of !blk_is_available(blk), we will still call bdrv_drained_end() in .clean even though bdrv_drained_begin() hasn't been called yet. Kevin