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Diffstat (limited to 'Documentation/lguest/lguest.c')
| -rw-r--r-- | Documentation/lguest/lguest.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index f2dbbf3..d36fcc0 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -1630,6 +1630,13 @@ static bool service_io(struct device *dev) } } + /* OK, so we noted that it was pretty poor to use an fdatasync as a + * barrier. But Christoph Hellwig points out that we need a sync + * *afterwards* as well: "Barriers specify no reordering to the front + * or the back." And Jens Axboe confirmed it, so here we are: */ + if (out->type & VIRTIO_BLK_T_BARRIER) + fdatasync(vblk->fd); + /* We can't trigger an IRQ, because we're not the Launcher. It does * that when we tell it we're done. */ add_used(dev->vq, head, wlen); |