Merge branch 'x86/cpu' into x86/core

[linux-2.6-omap-h63xx.git] / drivers / video / fb_defio.c

diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
index 24843fdd5395d981c0d27000b895fd0dc8ba32d9..4835bdc4e9f1819615ab2454549f9a637d01a0e1 100644 (file)
--- a/drivers/video/fb_defio.c
+++ b/drivers/video/fb_defio.c
@@ -74,6 +74,7 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
 {
        struct fb_info *info = vma->vm_private_data;
        struct fb_deferred_io *fbdefio = info->fbdefio;
+       struct page *cur;
 
        /* this is a callback we get when userspace first tries to
        write to the page. we schedule a workqueue. that workqueue
@@ -83,7 +84,24 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
 
        /* protect against the workqueue changing the page list */
        mutex_lock(&fbdefio->lock);
-       list_add(&page->lru, &fbdefio->pagelist);
+
+       /* we loop through the pagelist before adding in order
+       to keep the pagelist sorted */
+       list_for_each_entry(cur, &fbdefio->pagelist, lru) {
+               /* this check is to catch the case where a new
+               process could start writing to the same page
+               through a new pte. this new access can cause the
+               mkwrite even when the original ps's pte is marked
+               writable */
+               if (unlikely(cur == page))
+                       goto page_already_added;
+               else if (cur->index > page->index)
+                       break;
+       }
+
+       list_add_tail(&page->lru, &cur->lru);
+
+page_already_added:
        mutex_unlock(&fbdefio->lock);
 
        /* come back after delay to process the deferred IO */
@@ -96,6 +114,17 @@ static struct vm_operations_struct fb_deferred_io_vm_ops = {
        .page_mkwrite   = fb_deferred_io_mkwrite,
 };
 
+static int fb_deferred_io_set_page_dirty(struct page *page)
+{
+       if (!PageDirty(page))
+               SetPageDirty(page);
+       return 0;
+}
+
+static const struct address_space_operations fb_deferred_io_aops = {
+       .set_page_dirty = fb_deferred_io_set_page_dirty,
+};
+
 static int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
        vma->vm_ops = &fb_deferred_io_vm_ops;
@@ -145,6 +174,14 @@ void fb_deferred_io_init(struct fb_info *info)
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_init);
 
+void fb_deferred_io_open(struct fb_info *info,
+                        struct inode *inode,
+                        struct file *file)
+{
+       file->f_mapping->a_ops = &fb_deferred_io_aops;
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_open);
+
 void fb_deferred_io_cleanup(struct fb_info *info)
 {
        void *screen_base = (void __force *) info->screen_base;