mm: Don't use CMA pages for writes

If CMA pages are used for writes, the writes may not complete
fast enough for CMA to be allocated within a reasonable amount
of time. If we get a CMA page, get another one to use instead.

Change-Id: I19d8ba655da7525d68d5947337d500566998971c
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

mm/filemap.c

@@ -2343,9 +2343,17 @@ repeat:
 	if (page)
 		goto found;
 
+retry:
 	page = __page_cache_alloc(gfp_mask & ~gfp_notmask);
 	if (!page)
 		return NULL;
+
+	if (is_cma_pageblock(page)) {
+		__free_page(page);
+		gfp_notmask |= __GFP_MOVABLE;
+		goto retry;
+	}
+
 	status = add_to_page_cache_lru(page, mapping, index,
 						GFP_KERNEL & ~gfp_notmask);
 	if (unlikely(status)) {