{
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
/* 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 */
.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;
}
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;