From 58fda173e1156d24e5ff62361774715152188a07 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 2 Jul 2013 15:36:25 +0200 Subject: [PATCH] block: fix bdrv_flush() ordering in bdrv_close() Since 80ccf93b we flush the block device during close. The bdrv_drain_all() call should come before bdrv_flush() to ensure guest write requests have completed. Otherwise we may miss pending writes when flushing. Call bdrv_drain_all() again for safety as the final step after bdrv_flush(). This should not be necessary but we can be paranoid here in case bdrv_flush() left I/O pending. Cc: qemu-stable@nongnu.org Signed-off-by: Stefan Hajnoczi Reviewed-by: Kevin Wolf --- block.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 6c493ad457..183fec8aa5 100644 --- a/block.c +++ b/block.c @@ -1358,11 +1358,12 @@ void bdrv_reopen_abort(BDRVReopenState *reopen_state) void bdrv_close(BlockDriverState *bs) { - bdrv_flush(bs); if (bs->job) { block_job_cancel_sync(bs->job); } - bdrv_drain_all(); + bdrv_drain_all(); /* complete I/O */ + bdrv_flush(bs); + bdrv_drain_all(); /* in case flush left pending I/O */ notifier_list_notify(&bs->close_notifiers, bs); if (bs->drv) {