[PATCH] BLOCK: Separate the bounce buffering code from the highmem code [try #6]

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

diff --git a/mm/rmap.c b/mm/rmap.c
index 40158b5..e2155d7 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -434,6 +434,71 @@ int page_referenced(struct page *page, int is_locked)
        return referenced;
 }
 
+static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
+{
+       struct mm_struct *mm = vma->vm_mm;
+       unsigned long address;
+       pte_t *pte, entry;
+       spinlock_t *ptl;
+       int ret = 0;
+
+       address = vma_address(page, vma);
+       if (address == -EFAULT)
+               goto out;
+
+       pte = page_check_address(page, mm, address, &ptl);
+       if (!pte)
+               goto out;
+
+       if (!pte_dirty(*pte) && !pte_write(*pte))
+               goto unlock;
+
+       entry = ptep_get_and_clear(mm, address, pte);
+       entry = pte_mkclean(entry);
+       entry = pte_wrprotect(entry);
+       ptep_establish(vma, address, pte, entry);
+       lazy_mmu_prot_update(entry);
+       ret = 1;
+
+unlock:
+       pte_unmap_unlock(pte, ptl);
+out:
+       return ret;
+}
+
+static int page_mkclean_file(struct address_space *mapping, struct page *page)
+{
+       pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+       struct vm_area_struct *vma;
+       struct prio_tree_iter iter;
+       int ret = 0;
+
+       BUG_ON(PageAnon(page));
+
+       spin_lock(&mapping->i_mmap_lock);
+       vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+               if (vma->vm_flags & VM_SHARED)
+                       ret += page_mkclean_one(page, vma);
+       }
+       spin_unlock(&mapping->i_mmap_lock);
+       return ret;
+}
+
+int page_mkclean(struct page *page)
+{
+       int ret = 0;
+
+       BUG_ON(!PageLocked(page));
+
+       if (page_mapped(page)) {
+               struct address_space *mapping = page_mapping(page);
+               if (mapping)
+                       ret = page_mkclean_file(mapping, page);
+       }
+
+       return ret;
+}
+
 /**
  * page_set_anon_rmap - setup new anonymous rmap
  * @page:      the page to add the mapping to