From: Andrew Morton <akpm@digeo.com>
To: Daniel Phillips <phillips@arcor.de>
Cc: Rik van Riel <riel@conectiva.com.br>,
trond.myklebust@fys.uio.no, Chuck Lever <cel@citi.umich.edu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: invalidate_inode_pages in 2.5.32/3
Date: Mon, 09 Sep 2002 15:03:32 -0700 [thread overview]
Message-ID: <3D7D1AB4.B465ABE8@digeo.com> (raw)
In-Reply-To: E17oWKH-0006uw-00@starship
Daniel Phillips wrote:
>
> > I'm very unkeen about using the inaccurate invalidate_inode_pages
> > for anything which matters, really. And the consistency of pagecache
> > data matters.
> >
> > NFS should be using something stronger. And that's basically
> > vmtruncate() without the i_size manipulation.
>
> Yes, that looks good. Semantics are basically "and don't come back
> until every damm page is gone" which is enforced by the requirement
> that we hold the mapping->page_lock though one entire scan of the
> truncated region. (Yes, I remember sweating this one out a year
> or two ago so it doesn't eat 100% CPU on regular occasions.)
>
> So, specifically, we want:
>
> void invalidate_inode_pages(struct inode *inode)
> {
> truncate_inode_pages(mapping, 0);
> }
>
> Is it any harder than that?
Pretty much - need to leave i_size where it was. But there are
apparently reasons why NFS cannot sleepingly lock pages in this particular
context.
> By the way, now that we're all happy with the radix tree, we might
> as well just go traverse that instead of all the mapping->*_pages.
> (Not that I'm seriously suggesting rocking the boat that way just
> now, but it might yield some interesting de-crufting possibilities.)
Oh absolutely.
unsigned long radix_tree_gang_lookup(void **pointers,
unsiged long starting_from_here, unsigned long this_many);
could be used nicely in readahead, drop_behind, truncate, invalidate
and invalidate2. But to use it in writeback (desirable) we would need
additional metadata in radix_tree_node. One bit per page, which means
"this page is dirty" or "this subtree has dirty pages".
I keep saying this in the hope that someone will take pity and write it.
> ...
> Now, what is this invalidate_inode_pages2 seepage about? Called from
> one place. Sheesh.
heh. We still do have some O_DIRECT/pagecache coherency problems.
next prev parent reply other threads:[~2002-09-09 21:59 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-05 14:25 invalidate_inode_pages in 2.5.32/3 Chuck Lever
2002-09-05 18:27 ` Andrew Morton
2002-09-05 18:53 ` Chuck Lever
2002-09-05 19:17 ` Andrew Morton
2002-09-05 20:00 ` Trond Myklebust
2002-09-05 20:15 ` Andrew Morton
2002-09-05 20:27 ` Trond Myklebust
2002-09-05 20:37 ` Andrew Morton
2002-09-05 20:51 ` Trond Myklebust
2002-09-05 21:12 ` Andrew Morton
2002-09-05 21:31 ` Trond Myklebust
2002-09-05 22:19 ` Andrew Morton
2002-09-06 0:48 ` Trond Myklebust
2002-09-06 1:08 ` Andrew Morton
2002-09-06 6:49 ` Trond Myklebust
2002-09-07 8:37 ` Daniel Phillips
2002-09-07 16:09 ` Andrew Morton
2002-09-07 17:02 ` Andrew Morton
2002-09-07 8:24 ` Daniel Phillips
2002-09-07 16:06 ` Andrew Morton
2002-09-09 21:08 ` Daniel Phillips
2002-09-09 21:36 ` Andrew Morton
2002-09-09 22:12 ` Daniel Phillips
2002-09-07 18:47 ` Rik van Riel
2002-09-07 23:09 ` Andrew Morton
2002-09-09 21:44 ` Daniel Phillips
2002-09-09 22:03 ` Andrew Morton [this message]
2002-09-09 22:19 ` Daniel Phillips
2002-09-09 22:32 ` Andrew Morton
2002-09-10 16:57 ` Daniel Phillips
2002-09-09 23:51 ` Chuck Lever
2002-09-10 1:07 ` Daniel Phillips
2002-09-10 15:09 ` Chuck Lever
2002-09-10 16:13 ` Daniel Phillips
2002-09-10 19:04 ` Chuck Lever
2002-09-10 20:52 ` Daniel Phillips
2002-09-11 0:07 ` Andrew Morton
2002-09-11 0:27 ` Daniel Phillips
2002-09-11 0:38 ` Andrew Morton
2002-09-11 0:53 ` Daniel Phillips
2002-09-11 1:49 ` Andrew Morton
2002-09-11 2:14 ` Daniel Phillips
2002-09-11 16:18 ` Rik van Riel
2002-09-11 17:14 ` Daniel Phillips
2002-09-12 19:06 ` Daniel Phillips
2002-09-12 22:05 ` Urban Widmark
2002-09-12 22:21 ` Andrew Morton
2002-09-12 22:30 ` Rik van Riel
2002-09-12 22:43 ` Daniel Phillips
2002-09-12 22:51 ` Andrew Morton
2002-09-12 23:05 ` Randy.Dunlap
2002-09-12 23:23 ` Rik van Riel
2002-09-12 23:53 ` Daniel Phillips
2002-09-23 16:38 ` Trond Myklebust
2002-09-23 17:16 ` Daniel Phillips
2002-09-23 18:57 ` Andrew Morton
2002-09-23 20:41 ` Trond Myklebust
2002-09-23 20:49 ` Daniel Phillips
2002-09-23 22:43 ` Trond Myklebust
2002-09-24 5:09 ` Daniel Phillips
2002-09-24 16:40 ` Trond Myklebust
2002-09-23 19:13 ` Daniel Phillips
2002-09-13 4:19 ` Daniel Phillips
2002-09-13 4:52 ` Daniel Phillips
2002-09-14 9:58 ` Urban Widmark
2002-09-12 13:04 ` Trond Myklebust
2002-09-12 18:21 ` Andrew Morton
2002-09-12 21:15 ` Daniel Phillips
2002-09-12 21:38 ` Andrew Morton
2002-09-12 21:52 ` Daniel Phillips
2002-09-05 22:01 ` Chuck Lever
2002-09-05 22:23 ` Andrew Morton
2002-09-05 21:41 ` Chuck Lever
2002-09-06 9:35 ` Helge Hafting
2002-09-06 16:16 ` Chuck Lever
2002-09-07 8:01 ` Daniel Phillips
2002-09-07 10:01 ` Daniel Phillips
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