[PATCH] mm: fallback_alloc cpuset_zone_allowed irq fix

fallback_alloc() could end up calling cpuset_zone_allowed() with interrupts
disabled (by code in kmem_cache_alloc_node()), but without __GFP_HARDWALL
set, leading to a possible call of a sleeping function with interrupts
disabled.

This results in the BUG report:

  BUG: sleeping function called from invalid context at kernel/cpuset.c:1520
in_atomic():0, irqs_disabled():1

Thanks to Paul Menage for catching this one.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/slab.c b/mm/slab.c
index 068cb45..e90b610 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3182,7 +3182,7 @@ retry:
        for (z = zonelist->zones; *z && !obj; z++) {
                nid = zone_to_nid(*z);
 
-               if (cpuset_zone_allowed(*z, flags) &&
+               if (cpuset_zone_allowed(*z, flags | __GFP_HARDWALL) &&
                        cache->nodelists[nid] &&
                        cache->nodelists[nid]->free_objects)
                                obj = ____cache_alloc_node(cache,