From: Minchan Kim <minchan.kim@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
Dan Magenheimer <dan.magenheimer@oracle.com>,
linux-next@vger.kernel.org, linux-kernel@vger.kernel.org,
Linus <torvalds@linux-foundation.org>
Subject: Re: linux-next: manual merge of the cleancache tree with Linus' tree
Date: Thu, 24 Mar 2011 14:58:06 +0900 [thread overview]
Message-ID: <AANLkTimQQHHN6pS17R_mGmF+oG33D3Apb6E_pNvsLHwv@mail.gmail.com> (raw)
In-Reply-To: <AANLkTikagME334Y6PH4P_Nybf_h=fov5CiNBAY7KxYyN@mail.gmail.com>
On Thu, Mar 24, 2011 at 2:38 PM, Minchan Kim <minchan.kim@gmail.com> wrote:
> On Thu, Mar 24, 2011 at 12:56 PM, Andrew Morton
> <akpm@linux-foundation.org> wrote:
>> On Thu, 24 Mar 2011 13:55:24 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>>
>>> Hi Dan,
>>>
>>> Today's linux-next merge of the cleancache tree got a conflict in
>>> mm/truncate.c between commit 5adc7b518b54 ("mm: truncate: change
>>> remove_from_page_cache") from Linus' tree and commit 03e838947c8a
>>> ("mm/fs: add hooks to support cleancache") from the cleancache tree.
>>>
>>> I fixed it up (see below) but am really not sure of the fix. I can carry
>>> this fix as necessary.
>>>
>>> Is this stuff going to be merged into Linus' tree this time round?
>>> --
>>> Cheers,
>>> Stephen Rothwell sfr@canb.auug.org.au
>>>
>>> diff --cc mm/truncate.c
>>> index a956675,cd94607..0000000
>>> --- a/mm/truncate.c
>>> +++ b/mm/truncate.c
>>> @@@ -106,8 -108,13 +108,12 @@@ truncate_complete_page(struct address_s
>>> cancel_dirty_page(page, PAGE_CACHE_SIZE);
>>>
>>> clear_page_mlock(page);
>>> - remove_from_page_cache(page);
>>> ClearPageMappedToDisk(page);
>>> + delete_from_page_cache(page);
>>> + /* this must be after the remove_from_page_cache which
>>> + * calls cleancache_put_page (and note page->mapping is now NULL)
>>> + */
>>> + cleancache_flush_page(mapping, page);
>>> - page_cache_release(page); /* pagecache ref */
>>> return 0;
>>> }
>>
>> I did the cleancache_flush_page() before the delete_from_page_cache(),
>> in case the delete_from_page_cache() freed the page. I didn't actually
>> check whether that makes sense though.
>
> I am not sure cleancache's put and flush semantic.
> If I understand rightly with old __remove_from_page_cache's comment,
> maybe cleancache_flush_page is to invalidate the page.(If I understand
> right, I hope the name is changed to cleancache_invalidate_page)
>
> " /*
> * if we're uptodate, flush out into the cleancache, otherwise
> * invalidate any existing cleancache entries. We can't leave
> * stale data around in the cleancache once our page is gone
> */
> if (PageUptodate(page))
> cleancache_put_page(page);
> else
> cleancache_flush_page(mapping, page); "
>
> So I think cleancache_flush_page should be done after
> delete_from_page_cache because delete_from_page_cache calls
> cleancache_put_page(maybe this function would flush the content of
> memory into cleancache's target) before we invalidates the page.
>
> And it should not be a problem in case the delete_from_page_cache
> freed the page since cleancache should have a reference the page but I
> didn't check cleancahe always has a reference of page. If it isn't,
> it's a critical problem.
>
> Dan, Could you comment this?
Dan, one more thing.
#define cleancache_fs_enabled_mapping(_mapping) \
(mapping->host->i_sb->cleancache_poolid >= 0)
One is "_mapping", another is "mapping"
--
Kind regards,
Minchan Kim
next prev parent reply other threads:[~2011-03-24 5:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-24 2:55 linux-next: manual merge of the cleancache tree with Linus' tree Stephen Rothwell
2011-03-24 3:56 ` Andrew Morton
2011-03-24 5:38 ` Minchan Kim
2011-03-24 5:58 ` Minchan Kim [this message]
2011-03-24 6:42 ` Andrew Morton
2011-03-24 15:37 ` Dan Magenheimer
2011-04-14 21:04 ` Dan Magenheimer
-- strict thread matches above, loose matches on Subject: below --
2011-02-14 6:17 Stephen Rothwell
2011-01-15 1:44 Stephen Rothwell
2011-01-14 1:12 Stephen Rothwell
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