Messages in this thread | | | Date | Wed, 13 Dec 2006 17:41:48 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] nfs: fix NR_FILE_DIRTY underflow |
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On Wed, 13 Dec 2006 17:29:21 -0800 Andrew Morton <akpm@osdl.org> wrote:
> a) we're now calling try_to_release_page() with a potentially-dirty > page, whereas it was previously clean. > > I wouldn't expect ->releasepage() implementations to go looking at > PG_Dirty, because that's not what they're suppoed to be interested in. > But they might do, dunno.
Still an issue, probably minor.
> b) If invalidate_complete_page2() failed due to, say, dirty buffer_heads > then we now have a clean page with dirty buffers. That is an illegal > state and the page will leak permanently. > > I _think_ that's what the was_dirty logic is in there for: to > preserve the correct page-vs-buffers dirtiness coherency. But I'd need > to do some 2.5.x changelog-dumpster-diving to be sure.
no, that's bs. The patch looks OK from that POV: try_to_release_page() will be able to clear clean buffers from a dirty page.
And in fact if it did that, it will then clean the page for us (see test_clear_page_dirty() in try_to_free_buffers()).
But we still need the clear_page_dirty() in invalidate_complete_page2() in case we didn't call try_to_release_page() at all.
> Trond, please define precisely and completely and without reference to > the existing implementation: what behaviour does NFS want?
But this would be nice. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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