mm: rotate_reclaimable_page() cleanup

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

diff --git a/mm/mmap.c b/mm/mmap.c
index 8295577..6aaf657 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -36,6 +36,10 @@
 #define arch_mmap_check(addr, len, flags)      (0)
 #endif
 
+#ifndef arch_rebalance_pgtables
+#define arch_rebalance_pgtables(addr, len)             (addr)
+#endif
+
 static void unmap_region(struct mm_struct *mm,
                struct vm_area_struct *vma, struct vm_area_struct *prev,
                unsigned long start, unsigned long end);
@@ -241,7 +245,7 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 
        down_write(&mm->mmap_sem);
 
-       if (brk < mm->end_code)
+       if (brk < mm->start_brk)
                goto out;
 
        /*
@@ -1064,7 +1068,6 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
                mapping_cap_account_dirty(vma->vm_file->f_mapping);
 }
 
-
 unsigned long mmap_region(struct file *file, unsigned long addr,
                          unsigned long len, unsigned long flags,
                          unsigned int vm_flags, unsigned long pgoff,
@@ -1177,22 +1180,20 @@ munmap_back:
        if (vma_wants_writenotify(vma))
                vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
 
-       if (!file || !vma_merge(mm, prev, addr, vma->vm_end,
+       if (file && vma_merge(mm, prev, addr, vma->vm_end,
                        vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
-               file = vma->vm_file;
-               vma_link(mm, vma, prev, rb_link, rb_parent);
-               if (correct_wcount)
-                       atomic_inc(&inode->i_writecount);
-       } else {
-               if (file) {
-                       if (correct_wcount)
-                               atomic_inc(&inode->i_writecount);
-                       fput(file);
-               }
                mpol_free(vma_policy(vma));
                kmem_cache_free(vm_area_cachep, vma);
+               fput(file);
+       } else {
+               vma_link(mm, vma, prev, rb_link, rb_parent);
+               file = vma->vm_file;
        }
-out:   
+
+       /* Once vma denies write, undo our temporary denial count */
+       if (correct_wcount)
+               atomic_inc(&inode->i_writecount);
+out:
        mm->total_vm += len >> PAGE_SHIFT;
        vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
        if (vm_flags & VM_LOCKED) {
@@ -1424,7 +1425,7 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
        if (addr & ~PAGE_MASK)
                return -EINVAL;
 
-       return addr;
+       return arch_rebalance_pgtables(addr, len);
 }
 
 EXPORT_SYMBOL(get_unmapped_area);
@@ -2161,24 +2162,31 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
 }
 
 
-static struct page *special_mapping_nopage(struct vm_area_struct *vma,
-                                          unsigned long address, int *type)
+static int special_mapping_fault(struct vm_area_struct *vma,
+                               struct vm_fault *vmf)
 {
+       pgoff_t pgoff;
        struct page **pages;
 
-       BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+       /*
+        * special mappings have no vm_file, and in that case, the mm
+        * uses vm_pgoff internally. So we have to subtract it from here.
+        * We are allowed to do this because we are the mm; do not copy
+        * this code into drivers!
+        */
+       pgoff = vmf->pgoff - vma->vm_pgoff;
 
-       address -= vma->vm_start;
-       for (pages = vma->vm_private_data; address > 0 && *pages; ++pages)
-               address -= PAGE_SIZE;
+       for (pages = vma->vm_private_data; pgoff && *pages; ++pages)
+               pgoff--;
 
        if (*pages) {
                struct page *page = *pages;
                get_page(page);
-               return page;
+               vmf->page = page;
+               return 0;
        }
 
-       return NOPAGE_SIGBUS;
+       return VM_FAULT_SIGBUS;
 }
 
 /*
@@ -2190,7 +2198,7 @@ static void special_mapping_close(struct vm_area_struct *vma)
 
 static struct vm_operations_struct special_mapping_vmops = {
        .close = special_mapping_close,
-       .nopage = special_mapping_nopage,
+       .fault = special_mapping_fault,
 };
 
 /*