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. LKML-Reference: <20100525160149.GE20853@laptop> Signed-off-by: Albert Herranz <albert_herranz@xxxxxxxx> --- drivers/video/fb_defio.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-) diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c index 0e4dcdb..a3e8cc7 100644 --- a/drivers/video/fb_defio.c +++ b/drivers/video/fb_defio.c @@ -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 = { -- 1.7.0.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>