[PATCH] invalidate_complete_page() race fix
If a CPU faults this page into pagetables after invalidate_mapping_pages()
checked page_mapped(), invalidate_complete_page() will still proceed to remove
the page from pagecache. This leaves the page-faulting process with a
detached page. If it was MAP_SHARED then file data loss will ensue.
Fix that up by checking the page's refcount after taking tree_lock.
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 file changed