[PATCH] [3/16] HWPOISON: Export some rmap vma locking to outside world

Andi Kleen
2009-05-29T21:36:08Z

Needed for later patch that walks rmap entries on its own.

This used to be very frowned upon, but memory-failure.c does
some rather specialized rmap walking and rmap has been stable
for quite some time, so I think it's ok now to export it.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
include/linux/rmap.h | 6 ++++++
mm/rmap.c | 4 ++--
2 files changed, 8 insertions(+), 2 deletions(-)

Index: linux/include/linux/rmap.h
===================================================================
--- linux.orig/include/linux/rmap.h 2009-05-29 23:32:10.000000000 +0200
+++ linux/include/linux/rmap.h 2009-05-29 23:33:30.000000000 +0200
@@ -118,6 +118,12 @@
}
#endif

+/*
+ * Called by memory-failure.c to kill processes.
+ */
+struct anon_vma *page_lock_anon_vma(struct page *page);
+void page_unlock_anon_vma(struct anon_vma *anon_vma);
+
#else /* !CONFIG_MMU */

#define anon_vma_init() do {} while (0)
Index: linux/mm/rmap.c
===================================================================
--- linux.orig/mm/rmap.c 2009-05-29 23:32:10.000000000 +0200
+++ linux/mm/rmap.c 2009-05-29 23:33:30.000000000 +0200
@@ -191,7 +191,7 @@
* Getting a lock on a stable anon_vma from a page off the LRU is
* tricky: page_lock_anon_vma rely on RCU to guard against the races.
*/
-static struct anon_vma *page_lock_anon_vma(struct page *page)
+struct anon_vma *page_lock_anon_vma(struct page *page)
{
struct anon_vma *anon_vma;
unsigned long anon_mapping;
@@ -211,7 +211,7 @@
return NULL;
}

-static void page_unlock_anon_vma(struct anon_vma *anon_vma)
+void page_unlock_anon_vma(struct anon_vma *anon_vma)
{
spin_unlock(&anon_vma->lock);
rcu_read_unlock();