cfq-iosched: fix rcu freeing of cfq io contexts

SLAB_DESTROY_BY_RCU is not a direct substitute for normal call_rcu()
freeing, since it'll page freeing but NOT object freeing. So change
cfq to do the freeing on its own.

Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index 1b4ccf25b4d2..cac4b364cd40 100644
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -2,6 +2,7 @@
 #define IOCONTEXT_H
 
 #include <linux/radix-tree.h>
+#include <linux/rcupdate.h>
 
 /*
  * This is the per-process anticipatory I/O scheduler state.
@@ -54,6 +55,8 @@ struct cfq_io_context {
 
         void (*dtor)(struct io_context *); /* destructor */
         void (*exit)(struct io_context *); /* called on task exit */
+
+        struct rcu_head rcu_head;
 };
 
 /*