fb_defio: redo fix for non-dirty ptes (d6d03f91) · Commits · 戴 / test

As pointed by Nick Piggin, ->page_mkwrite provides a way to keep a page locked until the associated PTE is marked dirty. Re-implement the fix by using this mechanism. Signed-off-by:

Albert Herranz <albert_herranz@yahoo.es> Acked-by:

Jaya Kumar <jayakumar.lkml@gmail.com> Acked-by:

Nick Piggin <npiggin@suse.de> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/fb_defio.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -100,6 +100,16 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
		/* protect against the workqueue changing the page list */
		mutex_lock(&fbdefio->lock);

		/*
		* We want the page to remain locked from ->page_mkwrite until
		* the PTE is marked dirty to avoid page_mkclean() being called
		* before the PTE is updated, which would leave the page ignored
		* by defio.
		* Do this by locking the page here and informing the caller
		* about it with VM_FAULT_LOCKED.
		*/
		lock_page(page);

		/* we loop through the pagelist before adding in order
		to keep the pagelist sorted */
		list_for_each_entry(cur, &fbdefio->pagelist, lru) {
		@@ -121,7 +131,7 @@ page_already_added:

		/* come back after delay to process the deferred IO */
		schedule_delayed_work(&info->deferred_work, fbdefio->delay);
		return 0;
		return VM_FAULT_LOCKED;
		}

		static const struct vm_operations_struct fb_deferred_io_vm_ops = {

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