[Devel] [PATCH v4 04/25] Wipe out CFLGS_OFF_SLAB from flags during initial slab creation

[Glauber Costa]

CFLGS_OFF_SLAB is not a valid flag to be passed to cache creation.
If we are duplicating a cache - support added in a future patch -
we will rely on the flags it has stored in itself. That may include
CFLGS_OFF_SLAB.

So it is better to clean this flag at cache creation.

CC: Christoph Lameter <cl at linux.com>
CC: Pekka Enberg <penberg at cs.helsinki.fi>
CC: David Rientjes <rientjes at google.com>
---
 mm/slab.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/slab.c b/mm/slab.c
index 2d5fe28..c30a61c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2201,6 +2201,12 @@ int __kmem_cache_create(struct kmem_cache *cachep)
 		BUG_ON(flags & SLAB_POISON);
 #endif
 	/*
+	 * Passing this flag at creation time is invalid, but if we're
+	 * duplicating a slab, it may happen.
+	 */
+	flags &= ~CFLGS_OFF_SLAB;
+
+	/*
 	 * Always checks flags, a caller might be expecting debug support which
 	 * isn't available.
 	 */
-- 
1.7.10.2