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    Subject[PATCH] xen/gntdev: do not set VM_PFNMAP
    Since when we are using the m2p_override it is not true anymore that the
    mmap'ed area doesn't have corresponsing struct pages.

    Removing the VM_PFNMAP flag makes get_user_pages work on the mmap'ed user vma.
    An example test case would be using a Xen userspace block backend
    (QDISK) on a file on NFS using O_DIRECT.

    The patch should be backported back to 2.6.38.

    Signed-off-by: Stefano Stabellini <>
    drivers/xen/gntdev.c | 2 +-
    1 files changed, 1 insertions(+), 1 deletions(-)

    diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
    index 99d8151..1ffd03b 100644
    --- a/drivers/xen/gntdev.c
    +++ b/drivers/xen/gntdev.c
    @@ -722,7 +722,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
    vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND;

    if (use_ptemod)
    - vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP;
    + vma->vm_flags |= VM_DONTCOPY;

    vma->vm_private_data = map;


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      Last update: 2012-04-03 13:25    [W:0.021 / U:8.028 seconds]
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