Commit d847471d authored by Ian Campbell's avatar Ian Campbell Committed by Linus Torvalds
Browse files

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 14fcc23f
  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: default avatarIan 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> [14fcc23f is in 2.6.25.14 and 2.6.26.1]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b42f9317

drivers/video/fb_defio.c

+19 −0
Original line number Diff line number Diff line
@@ -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;

drivers/video/fbmem.c

+4 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/fb.h

+3 −0
Original line number Diff line number Diff line
@@ -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);

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