mm/page_alloc.c: apply gfp_allowed_mask before the first allocation attempt

We are by error initializing alloc_flags before gfp_allowed_mask is
applied.  This could cause problems after pm_restrict_gfp_mask() is called
during suspend operation.  Apply gfp_allowed_mask before initializing
alloc_flags so that the first allocation attempt uses correct flags.

Link: http://lkml.kernel.org/r/201709020016.ADJ21342.OFLJHOOSMFVtFQ@I-love.SAKURA.ne.jp
Fixes: 83d4ca8148fd9092 ("mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 45583cd..c841af8 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4183,10 +4183,11 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
 {
        struct page *page;
        unsigned int alloc_flags = ALLOC_WMARK_LOW;
-       gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
+       gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
        struct alloc_context ac = { };
 
        gfp_mask &= gfp_allowed_mask;
+       alloc_mask = gfp_mask;
        if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags))
                return NULL;