From: Andi Kleen <andi@firstfloor.org>
Date: Wed, 16 Sep 2009 09:50:04 +0000 (+0200)
Subject: HWPOISON: Export some rmap vma locking to outside world
X-Git-Tag: v2.6.32-rc1~62^2~19
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=10be22dfe1e6ad978269dc275147e0ed049187bb

HWPOISON: Export some rmap vma locking to outside world

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>
---

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index bf116d0..8dff2ff 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -112,6 +112,12 @@ int page_mkclean(struct page *);
  */
 int try_to_munlock(struct page *);
 
+/*
+ * 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)
diff --git a/mm/rmap.c b/mm/rmap.c
index 0895b5c..5a35c03 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -191,7 +191,7 @@ void __init anon_vma_init(void)
  * 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 @@ out:
 	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();