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 (file)
--- 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 *);
 
  */
 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)
 #else  /* !CONFIG_MMU */
 
 #define anon_vma_init()                do {} while (0)

diff --git a/mm/rmap.c b/mm/rmap.c
index 0895b5c..5a35c03 100644 (file)
--- 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.
  */
  * 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;
 {
        struct anon_vma *anon_vma;
        unsigned long anon_mapping;


@@ -211,7 +211,7 @@ out:
        return NULL;
 }
 
        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();
 {
        spin_unlock(&anon_vma->lock);
        rcu_read_unlock();