Re: Mount ext3 with barrier=1 doesn't send real barrier bio?

From: Jens Axboe
Date: Fri Aug 22 2008 - 03:58:35 EST


On Fri, Aug 22 2008, OGAWA Hirofumi wrote:
> Jens Axboe <jens.axboe@xxxxxxxxxx> writes:
>
> >> This should be ((rw & RW_MASK) == WRITE) too? Anyway, this seems change
> >> behavior of submit_bh(WRITE_BARRIER) (maybe reiserfs only), it wouldn't
> >> be your intent...
> >
> > Yes, I believe the simpler and more correct fix is:
> >
> > diff --git a/fs/buffer.c b/fs/buffer.c
> > index 38653e3..16b2263 100644
> > --- a/fs/buffer.c
> > +++ b/fs/buffer.c
> > @@ -2926,14 +2926,13 @@ int submit_bh(int rw, struct buffer_head * bh)
> > BUG_ON(!buffer_mapped(bh));
> > BUG_ON(!bh->b_end_io);
> >
> > - if (buffer_ordered(bh) && (rw == WRITE))
> > + if (buffer_ordered(bh) && (rw & WRITE))
> > rw = WRITE_BARRIER;
>
> I see. But, umm..., this means WRITE_SYNC with barrier was deprecated?
> Or typo?

It was supposed to read rw |= WRITE_BARRIER :-)

--
Jens Axboe

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