mm/memory_hotplug: update comment regarding zone shuffling

[linux-2.6-microblaze.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index f793eb7..67d11ad 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -143,7 +143,7 @@ static void __remove_shared_vm_struct(struct vm_area_struct *vma,
                struct file *file, struct address_space *mapping)
 {
        if (vma->vm_flags & VM_DENYWRITE)
-               atomic_inc(&file_inode(file)->i_writecount);
+               allow_write_access(file);
        if (vma->vm_flags & VM_SHARED)
                mapping_unmap_writable(mapping);
 
@@ -474,8 +474,12 @@ static __always_inline void vma_rb_erase_ignore(struct vm_area_struct *vma,
 {
        /*
         * All rb_subtree_gap values must be consistent prior to erase,
-        * with the possible exception of the "next" vma being erased if
-        * next->vm_start was reduced.
+        * with the possible exception of
+        *
+        * a. the "next" vma being erased if next->vm_start was reduced in
+        *    __vma_adjust() -> __vma_unlink()
+        * b. the vma being erased in detach_vmas_to_be_unmapped() ->
+        *    vma_rb_erase()
         */
        validate_mm_rb(root, ignore);
 
@@ -485,13 +489,7 @@ static __always_inline void vma_rb_erase_ignore(struct vm_area_struct *vma,
 static __always_inline void vma_rb_erase(struct vm_area_struct *vma,
                                         struct rb_root *root)
 {
-       /*
-        * All rb_subtree_gap values must be consistent prior to erase,
-        * with the possible exception of the vma being erased.
-        */
-       validate_mm_rb(root, vma);
-
-       __vma_rb_erase(vma, root);
+       vma_rb_erase_ignore(vma, root, vma);
 }
 
 /*
@@ -623,7 +621,7 @@ static void __vma_link_file(struct vm_area_struct *vma)
                if (vma->vm_flags & VM_DENYWRITE)
                        atomic_dec(&file_inode(file)->i_writecount);
                if (vma->vm_flags & VM_SHARED)
-                       atomic_inc(&mapping->i_mmap_writable);
+                       mapping_allow_writable(mapping);
 
                flush_dcache_mmap_lock(mapping);
                vma_interval_tree_insert(vma, &mapping->i_mmap);
@@ -677,7 +675,7 @@ static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
        mm->map_count++;
 }
 
-static __always_inline void __vma_unlink_common(struct mm_struct *mm,
+static __always_inline void __vma_unlink(struct mm_struct *mm,
                                                struct vm_area_struct *vma,
                                                struct vm_area_struct *ignore)
 {
@@ -760,7 +758,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
                         * vma expands, overlapping part of the next:
                         * mprotect case 5 shifting the boundary up.
                         */
-                       adjust_next = (end - next->vm_start) >> PAGE_SHIFT;
+                       adjust_next = (end - next->vm_start);
                        exporter = next;
                        importer = vma;
                        VM_WARN_ON(expand != importer);
@@ -770,7 +768,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
                         * split_vma inserting another: so it must be
                         * mprotect case 4 shifting the boundary down.
                         */
-                       adjust_next = -((vma->vm_end - end) >> PAGE_SHIFT);
+                       adjust_next = -(vma->vm_end - end);
                        exporter = vma;
                        importer = next;
                        VM_WARN_ON(expand != importer);
@@ -825,7 +823,7 @@ again:
                        anon_vma_interval_tree_pre_update_vma(next);
        }
 
-       if (root) {
+       if (file) {
                flush_dcache_mmap_lock(mapping);
                vma_interval_tree_remove(vma, root);
                if (adjust_next)
@@ -842,11 +840,11 @@ again:
        }
        vma->vm_pgoff = pgoff;
        if (adjust_next) {
-               next->vm_start += adjust_next << PAGE_SHIFT;
-               next->vm_pgoff += adjust_next;
+               next->vm_start += adjust_next;
+               next->vm_pgoff += adjust_next >> PAGE_SHIFT;
        }
 
-       if (root) {
+       if (file) {
                if (adjust_next)
                        vma_interval_tree_insert(next, root);
                vma_interval_tree_insert(vma, root);
@@ -859,7 +857,7 @@ again:
                 * us to remove next before dropping the locks.
                 */
                if (remove_next != 3)
-                       __vma_unlink_common(mm, next, next);
+                       __vma_unlink(mm, next, next);
                else
                        /*
                         * vma is not before next if they've been
@@ -870,7 +868,7 @@ again:
                         * "next" (which is stored in post-swap()
                         * "vma").
                         */
-                       __vma_unlink_common(mm, next, vma);
+                       __vma_unlink(mm, next, vma);
                if (file)
                        __remove_shared_vm_struct(next, file, mapping);
        } else if (insert) {
@@ -897,10 +895,9 @@ again:
                        anon_vma_interval_tree_post_update_vma(next);
                anon_vma_unlock_write(anon_vma);
        }
-       if (mapping)
-               i_mmap_unlock_write(mapping);
 
-       if (root) {
+       if (file) {
+               i_mmap_unlock_write(mapping);
                uprobe_mmap(vma);
 
                if (adjust_next)
@@ -1666,7 +1663,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
 
        /* Can the mapping track the dirty pages? */
        return vma->vm_file && vma->vm_file->f_mapping &&
-               mapping_cap_account_dirty(vma->vm_file->f_mapping);
+               mapping_can_writeback(vma->vm_file->f_mapping);
 }
 
 /*
@@ -3236,7 +3233,7 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
         * By setting it to reflect the virtual start address of the
         * vma, merges and splits can happen in a seamless way, just
         * using the existing file pgoff checks and manipulations.
-        * Similarly in do_mmap and in do_brk.
+        * Similarly in do_mmap and in do_brk_flags.
         */
        if (vma_is_anonymous(vma)) {
                BUG_ON(vma->anon_vma);