Merge branch 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block

[pandora-kernel.git] / mm / rmap.c

diff --git a/mm/rmap.c b/mm/rmap.c
index d85a99d..1963e26 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -52,16 +52,15 @@
 #include <linux/init.h>
 #include <linux/rmap.h>
 #include <linux/rcupdate.h>
+#include <linux/module.h>
 
 #include <asm/tlbflush.h>
 
-//#define RMAP_DEBUG /* can be enabled only for debugging */
-
-kmem_cache_t *anon_vma_cachep;
+struct kmem_cache *anon_vma_cachep;
 
 static inline void validate_anon_vma(struct vm_area_struct *find_vma)
 {
-#ifdef RMAP_DEBUG
+#ifdef CONFIG_DEBUG_VM
        struct anon_vma *anon_vma = find_vma->anon_vma;
        struct vm_area_struct *vma;
        unsigned int mapcount = 0;
@@ -165,7 +164,8 @@ void anon_vma_unlink(struct vm_area_struct *vma)
                anon_vma_free(anon_vma);
 }
 
-static void anon_vma_ctor(void *data, kmem_cache_t *cachep, unsigned long flags)
+static void anon_vma_ctor(void *data, struct kmem_cache *cachep,
+                         unsigned long flags)
 {
        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
                                                SLAB_CTOR_CONSTRUCTOR) {
@@ -205,6 +205,44 @@ 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 and mmap_sem of one vma that contains
+ * the page.
+ */
+void remove_from_swap(struct page *page)
+{
+       struct anon_vma *anon_vma;
+       struct vm_area_struct *vma;
+       unsigned long mapping;
+
+       if (!PageSwapCache(page))
+               return;
+
+       mapping = (unsigned long)page->mapping;
+
+       if (!mapping || (mapping & PAGE_MAPPING_ANON) == 0)
+               return;
+
+       /*
+        * We hold the mmap_sem lock. So no need to call page_lock_anon_vma.
+        */
+       anon_vma = (struct anon_vma *) (mapping - PAGE_MAPPING_ANON);
+       spin_lock(&anon_vma->lock);
+
+       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?
  */
@@ -498,9 +536,6 @@ void page_add_new_anon_rmap(struct page *page,
  */
 void page_add_file_rmap(struct page *page)
 {
-       BUG_ON(PageAnon(page));
-       BUG_ON(!pfn_valid(page_to_pfn(page)));
-
        if (atomic_inc_and_test(&page->_mapcount))
                __inc_page_state(nr_mapped);
 }
@@ -514,13 +549,14 @@ void page_add_file_rmap(struct page *page)
 void page_remove_rmap(struct page *page)
 {
        if (atomic_add_negative(-1, &page->_mapcount)) {
-               if (page_mapcount(page) < 0) {
+#ifdef CONFIG_DEBUG_VM
+               if (unlikely(page_mapcount(page) < 0)) {
                        printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page_mapcount(page));
                        printk (KERN_EMERG "  page->flags = %lx\n", page->flags);
                        printk (KERN_EMERG "  page->count = %x\n", page_count(page));
                        printk (KERN_EMERG "  page->mapping = %p\n", page->mapping);
                }
-
+#endif
                BUG_ON(page_mapcount(page) < 0);
                /*
                 * It would be tidy to reset the PageAnon mapping here,
@@ -541,7 +577,8 @@ 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 +601,8 @@ 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 +736,7 @@ 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 +747,7 @@ 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 +764,7 @@ 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 +778,7 @@ 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 +863,16 @@ 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;