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 14fcc23fdc78e9d32372553ccf21758a9bd56fa1
Author: Hugh Dickins <hugh@veritas.com>
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 <ijc@hellion.org.uk>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kel Modderman <kel@otaku42.de>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: <stable@kernel.org> [14fcc23fd is in 2.6.25.14 and 2.6.26.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
index 59df132..4835bdc 100644
--- a/drivers/video/fb_defio.c
+++ b/drivers/video/fb_defio.c
@@ -114,6 +114,17 @@
.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 @@
}
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
index 6b48780..98843c2 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1344,6 +1344,10 @@
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
index 3b8870e..531ccd5 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -976,6 +976,9 @@
/* 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);