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From: Jan Kara <jack@suse.cz>
To: linux-mm@kvack.org
Subject: Does swap_set_page_dirty() calling ->set_page_dirty() make sense?
Date: Mon, 17 Sep 2012 18:35:18 +0200	[thread overview]
Message-ID: <20120917163518.GD9150@quack.suse.cz> (raw)

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  Hi,

  I tripped over a crash in reiserfs which happened due to PageSwapCache
page being passed to reiserfs_set_page_dirty(). Now it's not that hard to
make reiserfs_set_page_dirty() check that case but I really wonder: Does it
make sense to call mapping->a_ops->set_page_dirty() for a PageSwapCache
page? The page is going to be written via direct IO so from the POV of the
filesystem there's no need for any dirtiness tracking. Also there are
several ->set_page_dirty() implementations which will spectacularly crash
because they do things like page->mapping->host, or call
__set_page_dirty_buffers() which expects buffer heads in page->private.
Or what is the reason for calling filesystem's set_page_dirty() function?

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

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             reply	other threads:[~2012-09-17 16:35 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-17 16:35 Jan Kara [this message]
2012-09-17 19:15 ` Does swap_set_page_dirty() calling ->set_page_dirty() make sense? Hugh Dickins
2012-09-18  2:16   ` Jan Kara
2012-09-18  8:51     ` Petr Tesarik
2012-09-18 10:02       ` Mel Gorman
2012-09-18  9:58   ` Mel Gorman

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