[patch 1/3] mm: fault vs invalidate/truncate check

Nick Piggin
2006-10-07T13:06:12Z

Add a bugcheck for Andrea's pagefault vs invalidate race. This is triggerable
for both linear and nonlinear pages with a userspace test harness (using
direct IO and truncate, respectively).

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

Index: linux-2.6/mm/filemap.c
===================================================================
--- linux-2.6.orig/mm/filemap.c
+++ linux-2.6/mm/filemap.c
@@ -120,6 +120,8 @@ void __remove_from_page_cache(struct pag
page->mapping = NULL;
mapping->nrpages--;
__dec_zone_page_state(page, NR_FILE_PAGES);
+
+ BUG_ON(page_mapped(page));
}

void remove_from_page_cache(struct page *page)