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Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c51
1 files changed, 42 insertions, 9 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index d85a99d28c03..df2c41c2a9a2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -52,6 +52,7 @@
#include <linux/init.h>
#include <linux/rmap.h>
#include <linux/rcupdate.h>
+#include <linux/module.h>
#include <asm/tlbflush.h>
@@ -205,6 +206,36 @@ out:
return anon_vma;
}
+#ifdef CONFIG_MIGRATION
+/*
+ * Remove an anonymous page from swap replacing the swap pte's
+ * through real pte's pointing to valid pages and then releasing
+ * the page from the swap cache.
+ *
+ * Must hold page lock on page.
+ */
+void remove_from_swap(struct page *page)
+{
+ struct anon_vma *anon_vma;
+ struct vm_area_struct *vma;
+
+ if (!PageAnon(page) || !PageSwapCache(page))
+ return;
+
+ anon_vma = page_lock_anon_vma(page);
+ if (!anon_vma)
+ return;
+
+ list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
+ remove_vma_swap(vma, page);
+
+ spin_unlock(&anon_vma->lock);
+
+ delete_from_swap_cache(page);
+}
+EXPORT_SYMBOL(remove_from_swap);
+#endif
+
/*
* At what user virtual address is page expected in vma?
*/
@@ -541,7 +572,8 @@ void page_remove_rmap(struct page *page)
* Subfunctions of try_to_unmap: try_to_unmap_one called
* repeatedly from either try_to_unmap_anon or try_to_unmap_file.
*/
-static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
+static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
+ int ignore_refs)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
@@ -564,7 +596,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
* skipped over this mm) then we should reactivate it.
*/
if ((vma->vm_flags & VM_LOCKED) ||
- ptep_clear_flush_young(vma, address, pte)) {
+ (ptep_clear_flush_young(vma, address, pte)
+ && !ignore_refs)) {
ret = SWAP_FAIL;
goto out_unmap;
}
@@ -698,7 +731,7 @@ static void try_to_unmap_cluster(unsigned long cursor,
pte_unmap_unlock(pte - 1, ptl);
}
-static int try_to_unmap_anon(struct page *page)
+static int try_to_unmap_anon(struct page *page, int ignore_refs)
{
struct anon_vma *anon_vma;
struct vm_area_struct *vma;
@@ -709,7 +742,7 @@ static int try_to_unmap_anon(struct page *page)
return ret;
list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
- ret = try_to_unmap_one(page, vma);
+ ret = try_to_unmap_one(page, vma, ignore_refs);
if (ret == SWAP_FAIL || !page_mapped(page))
break;
}
@@ -726,7 +759,7 @@ static int try_to_unmap_anon(struct page *page)
*
* This function is only called from try_to_unmap for object-based pages.
*/
-static int try_to_unmap_file(struct page *page)
+static int try_to_unmap_file(struct page *page, int ignore_refs)
{
struct address_space *mapping = page->mapping;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -740,7 +773,7 @@ static int try_to_unmap_file(struct page *page)
spin_lock(&mapping->i_mmap_lock);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
- ret = try_to_unmap_one(page, vma);
+ ret = try_to_unmap_one(page, vma, ignore_refs);
if (ret == SWAP_FAIL || !page_mapped(page))
goto out;
}
@@ -825,16 +858,16 @@ out:
* SWAP_AGAIN - we missed a mapping, try again later
* SWAP_FAIL - the page is unswappable
*/
-int try_to_unmap(struct page *page)
+int try_to_unmap(struct page *page, int ignore_refs)
{
int ret;
BUG_ON(!PageLocked(page));
if (PageAnon(page))
- ret = try_to_unmap_anon(page);
+ ret = try_to_unmap_anon(page, ignore_refs);
else
- ret = try_to_unmap_file(page);
+ ret = try_to_unmap_file(page, ignore_refs);
if (!page_mapped(page))
ret = SWAP_SUCCESS;