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From: Paul Clements <Paul.Clements@SteelEye.com>
To: ptb@it.uc3m.es
Cc: linux-raid@vger.kernel.org, Neil Brown <neilb@cse.unsw.edu.au>
Subject: Re: Questions answered by Neil Brown
Date: Mon, 24 Feb 2003 16:58:48 -0500	[thread overview]
Message-ID: <3E5A9598.3AED4AE5@SteelEye.com> (raw)
In-Reply-To: 200302242015.h1OKFhA04699@oboe.it.uc3m.es

"Peter T. Breuer" wrote:
 
> >
> > 3) it is not clear to me that I am doing accounting right on
> >    async writes (or indeed when resyncing and skipping blocks).
> >
> >    The last end_io always did
> >    io_request_done(bh->b_rsector, conf,
> >                           test_bit(R1BH_SyncPhase, &r1_bh->state));
> >    and now this can be done on the first end_io (along with the
> >    bh->b_end_io(bh, uptodate);) in  an async write. Is that right?

> Once you have called bh->b_end_io, you cannot touch that bh every
> again, as it might not even exist.
 
So I think this means that we really need to duplicate the buffer memory
(bh->b_page, bh->b_data) and point the mirror I/Os to the duplicated
buffer, so we can allow the original (master_bh) to be freed before all
the I/Os complete. We then free the duplicate when the last mirror I/O
completes, right?

--
Paul

  reply	other threads:[~2003-02-24 21:58 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-02-24 20:15 Questions answered by Neil Brown Peter T. Breuer
2003-02-24 21:58 ` Paul Clements [this message]
2003-02-25  3:10   ` Neil Brown
2003-02-25  9:11     ` Peter T. Breuer
2003-02-26  7:44       ` Paul Clements
2003-02-26  8:09         ` Peter T. Breuer
2003-02-26 16:41           ` Paul Clements
2003-02-26 17:26             ` Peter T. Breuer
2003-02-26 18:29               ` raid1 bitmap code [Was: Re: Questions answered by Neil Brown] Paul Clements
2003-02-26 19:15                 ` Peter T. Breuer
2003-02-26 22:12                   ` Neil Brown
2003-02-26 23:24                     ` Peter T. Breuer
2003-02-27  7:26                       ` Paul Clements
2003-02-27  8:48                         ` Peter T. Breuer
2003-02-27 15:47                           ` Paul Clements
2003-02-27  5:33                     ` Paul Clements
2003-02-27 10:35                       ` Peter T. Breuer
2003-02-27 10:50                         ` Peter T. Breuer
2003-02-27 16:51                         ` Paul Clements
2003-02-27 17:18                           ` Peter T. Breuer
2003-02-28 15:25                           ` Peter T. Breuer
2003-02-28 16:14                             ` Paul Clements
2003-02-28 16:23                               ` Peter T. Breuer
2003-02-26 21:45           ` Questions answered by Neil Brown Neil Brown
2003-02-26 21:41         ` Neil Brown

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