aio: ifdef fields in mm_struct

->ioctx_lock and ->ioctx_list are used only under CONFIG_AIO.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 11 insertions, 5 deletions

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 0042090a4d70..6b7029ab9c8e 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -259,11 +259,10 @@ struct mm_struct {
         unsigned long flags; /* Must use atomic bitops to access the bits */
 
         struct core_state *core_state; /* coredumping support */
-
-        /* aio bits */
+#ifdef CONFIG_AIO
         spinlock_t              ioctx_lock;
         struct hlist_head       ioctx_list;
-
+#endif
 #ifdef CONFIG_MM_OWNER
         /*
          * "owner" points to a task that is regarded as the canonical
diff --git a/kernel/fork.c b/kernel/fork.c
index b51fd2ccb2f1..e49f181ba1ca 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -434,6 +434,14 @@ __setup("coredump_filter=", coredump_filter_setup);
 
 #include <linux/init_task.h>
 
+static void mm_init_aio(struct mm_struct *mm)
+{
+#ifdef CONFIG_AIO
+        spin_lock_init(&mm->ioctx_lock);
+        INIT_HLIST_HEAD(&mm->ioctx_list);
+#endif
+}
+
 static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
         atomic_set(&mm->mm_users, 1);
@@ -447,10 +455,9 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
         set_mm_counter(mm, file_rss, 0);
         set_mm_counter(mm, anon_rss, 0);
         spin_lock_init(&mm->page_table_lock);
-        spin_lock_init(&mm->ioctx_lock);
-        INIT_HLIST_HEAD(&mm->ioctx_list);
         mm->free_area_cache = TASK_UNMAPPED_BASE;
         mm->cached_hole_size = ~0UL;
+        mm_init_aio(mm);
         mm_init_owner(mm, p);
 
         if (likely(!mm_alloc_pgd(mm))) {