[PATCH] hugetlb: follow_hugetlb_page for write access

Hoang-Nam Nguyen hnguyen at linux.vnet.ibm.com
Tue Nov 20 02:25:00 EST 2007

On Wednesday 07 November 2007 20:51, Adam Litke wrote:
> When calling get_user_pages(), a write flag is passed in by the caller to
> indicate if write access is required on the faulted-in pages.  Currently,
> follow_hugetlb_page() ignores this flag and always faults pages for
> read-only access.  This can cause data corruption because a device driver
> that calls get_user_pages() with write set will not expect COW faults to
> occur on the returned pages.
> This patch passes the write flag down to follow_hugetlb_page() and makes
> sure hugetlb_fault() is called with the right write_access parameter.
> Signed-off-by: Adam Litke <agl at us.ibm.com>
Apologize for this late response.
Tested on 2.6.23 with ehca and mthca. It works like a charm for me.

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