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 <[email protected]>
> ---
> 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
