Re: get_user_pages() with write=1 and force=1 gets read-only pages.

[Robin Holt <holt@sgi.com>]

After actually thinking, I realize the do_anonymous_page path changes
are pointless.  Please ignore those.

Thanks,
Robin
> Index: linux/mm/memory.c
> ===================================================================
> --- linux.orig/mm/memory.c	2005-07-31 05:39:24.161826311 -0500
> +++ linux/mm/memory.c	2005-07-31 06:26:33.687274327 -0500
> @@ -1768,17 +1768,17 @@ do_anonymous_page(struct mm_struct *mm, 
>  		spin_lock(&mm->page_table_lock);
>  		page_table = pte_offset_map(pmd, addr);
>  
> +		entry = maybe_mkwrite(pte_mkdirty(mk_pte(page,
> +						vma->vm_page_prot)), vma);
>  		if (!pte_none(*page_table)) {
> +			if (!pte_same(*page_table, entry))
> +				ret = VM_FAULT_RACE;
>  			pte_unmap(page_table);
>  			page_cache_release(page);
>  			spin_unlock(&mm->page_table_lock);
> -			ret = VM_FAULT_RACE;
>  			goto out;
>  		}
>  		inc_mm_counter(mm, rss);
> -		entry = maybe_mkwrite(pte_mkdirty(mk_pte(page,
> -							 vma->vm_page_prot)),
> -				      vma);
>  		lru_cache_add_active(page);
>  		SetPageReferenced(page);
>  		page_add_anon_rmap(page, vma, addr);
> @@ -1879,6 +1879,10 @@ retry:
>  	}
>  	page_table = pte_offset_map(pmd, address);
>  
> +	entry = mk_pte(new_page, vma->vm_page_prot);
> +	if (write_access)
> +		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
> +
>  	/*
>  	 * This silly early PAGE_DIRTY setting removes a race
>  	 * due to the bad i386 page protection. But it's valid
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