From 507306cc8ee7981894a96c380f42d80e2674cb04 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Fri, 23 Oct 2015 11:08:13 +0800 Subject: [PATCH] block: Add "drained begin/end" for internal snapshot 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 Signed-off-by: Kevin Wolf --- blockdev.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/blockdev.c b/blockdev.c index 52f44b2867..18712d25cc 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; } @@ -1465,7 +1469,7 @@ 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 +1480,7 @@ static void internal_snapshot_abort(BlkTransactionState *common) QEMUSnapshotInfo *sn = &state->sn; Error *local_error = NULL; - if (!bs) { + if (!state->created) { return; } @@ -1497,6 +1501,9 @@ static void internal_snapshot_clean(BlkTransactionState *common) common, common); if (state->aio_context) { + if (state->bs) { + bdrv_drained_end(state->bs); + } aio_context_release(state->aio_context); } }