| Message ID | 1372772185-10958-1-git-send-email-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
Am 02.07.2013 um 15:36 hat Stefan Hajnoczi geschrieben: > 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 <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
On Tue, Jul 02, 2013 at 03:36:25PM +0200, Stefan Hajnoczi wrote: > 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 <stefanha@redhat.com> > --- > v2: > * Drain after block_job_cancel_sync() [kwolf] > > block.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) Applied to my block tree: https://github.com/stefanha/qemu/commits/block Stefan
diff --git a/block.c b/block.c index 6c493ad..183fec8 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) {
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 <stefanha@redhat.com> --- v2: * Drain after block_job_cancel_sync() [kwolf] block.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)