fbdefio: add set_page_dirty handler to deferred IO FB

Fixes kernel BUG at lib/radix-tree.c:473. Previously the handler was incidentally provided by tmpfs but this was removed with: commit 14fcc23 Author: Hugh Dickins <[email protected]> Date: Mon Jul 28 15:46:19 2008 -0700 tmpfs: fix kernel BUG in shmem_delete_inode relying on this behaviour was incorrect in any case and the BUG also appeared when the device node was on an ext3 filesystem. v2: override a_ops at open() time rather than mmap() time to minimise races per AKPM's concerns. Signed-off-by: Ian Campbell <[email protected]> Cc: Jaya Kumar <[email protected]> Cc: Nick Piggin <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Jeremy Fitzhardinge <[email protected]> Cc: Kel Modderman <[email protected]> Cc: Markus Armbruster <[email protected]> Cc: Krzysztof Helt <[email protected]> Cc: <[email protected]> [14fcc23 is in 2.6.25.14 and 2.6.26.1] Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
hanmiltonxing · Aug 20, 2008 · d847471 · d847471
1 parent b42f931
commit d847471
Show file tree

Hide file tree

Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
@@ -114,6 +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;
@@ -163,6 +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;

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
@@ -1344,6 +1344,10 @@ fb_open(struct inode *inode, struct file *file)
 		if (res)
 			module_put(info->fbops->owner);
 	}
+#ifdef CONFIG_FB_DEFERRED_IO
+	if (info->fbdefio)
+		fb_deferred_io_open(info, inode, file);
+#endif
 out:
 	unlock_kernel();
 	return res;

diff --git a/include/linux/fb.h b/include/linux/fb.h
@@ -976,6 +976,9 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
 
 /* drivers/video/fb_defio.c */
 extern void fb_deferred_io_init(struct fb_info *info);
+extern void fb_deferred_io_open(struct fb_info *info,
+				struct inode *inode,
+				struct file *file);
 extern void fb_deferred_io_cleanup(struct fb_info *info);
 extern int fb_deferred_io_fsync(struct file *file, struct dentry *dentry,
 				int datasync);