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    SubjectRe: Pagecache: find_or_create_page does not call a proper page allocator function
    On Tue, 24 Apr 2007, Andrew Morton wrote:

    > No, think of the following scenario:
    >
    > - file I/O causes a read of an ext2 file's bitmap. The bitmap is
    > brought into /dev/hda1's pagecache using !__GFP_HIGHMEM
    >
    > - references are released against that page and it's now just clean
    > reclaimable pagecache
    >
    > - someone (say, an online filesystem checker or something) mmaps
    > /dev/hda1 and reads that page.
    >
    > - migration comes alnog and migrates that page into highmem
    >
    > - file I/O causes a read of that bitmap again. We find it in
    > /dev/hda's pagecache.

    Read of the bitmap? How would that work? Page cache lookup right?

    > Here's set_bh_page().

    A highmem page can have buffers???
    -
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