From: Ian Campbell Date: Wed, 20 Aug 2008 21:09:23 +0000 (-0700) Subject: fbdefio: add set_page_dirty handler to deferred IO FB X-Git-Tag: v2.6.27-rc4~2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d847471d063663b9f36927d265c66a270c0cfaab;p=linux-2.6 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 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 Cc: Jaya Kumar Cc: Nick Piggin Cc: Peter Zijlstra Cc: Hugh Dickins Cc: Johannes Weiner Cc: Jeremy Fitzhardinge Cc: Kel Modderman Cc: Markus Armbruster Cc: Krzysztof Helt Cc: [14fcc23fd is in 2.6.25.14 and 2.6.26.1] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c index 59df132cc3..4835bdc4e9 100644 --- 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 index 6b487801ee..98843c2ecf 100644 --- 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 index 3b8870e32a..531ccd5f59 100644 --- 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);