Revert "fb_defio: Remove custom address_space_operations"

Commit ccf953d8f3 makes framebuffers which use deferred I/O stop
displaying updates after the first one.  This is because the pages
handled by fb_defio no longer have a page_mapping().  That prevents
page_mkclean() from marking the PTEs as clean, and so writes are only
noticed the first time.

Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/YLZEhv0cpZp8uVE3@casper.infradead.org
This commit is contained in:
Matthew Wilcox 2021-06-01 15:30:30 +01:00 committed by Daniel Vetter
parent 8124c8a6b3
commit 0b78f8bcf4
3 changed files with 42 additions and 0 deletions

View File

@ -52,6 +52,13 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
get_page(page);
if (vmf->vma->vm_file)
page->mapping = vmf->vma->vm_file->f_mapping;
else
printk(KERN_ERR "no mapping available\n");
BUG_ON(!page->mapping);
page->index = vmf->pgoff;
vmf->page = page;
@ -144,6 +151,17 @@ static const 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,
};
int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
vma->vm_ops = &fb_deferred_io_vm_ops;
@ -194,12 +212,29 @@ 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)
{
struct fb_deferred_io *fbdefio = info->fbdefio;
struct page *page;
int i;
BUG_ON(!fbdefio);
cancel_delayed_work_sync(&info->deferred_work);
/* clear out the mapping that we setup */
for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {
page = fb_deferred_io_page(info, i);
page->mapping = NULL;
}
mutex_destroy(&fbdefio->lock);
}
EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);

View File

@ -1415,6 +1415,10 @@ __releases(&info->lock)
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_fb_info(info);
if (res)

View File

@ -659,6 +659,9 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
/* drivers/video/fb_defio.c */
int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
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, loff_t start,
loff_t end, int datasync);