Commit 58fda173 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi
Browse files

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: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 3494d650

block.c

+3 −2
Original line number Diff line number Diff line
@@ -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) {