Currently, filemap_fault() avoids race condition with truncate by checking page->mapping == mapping. This does not work for compound pages. This patch let it check compound_head(page)->mapping instead.
Acked-by: Rik van Riel <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Acked-by: Johannes Weiner <[email protected]> Signed-off-by: Song Liu <[email protected]> --- mm/filemap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/filemap.c b/mm/filemap.c index 7161fb937e78..d0bd9e585c2f 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2537,7 +2537,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) goto out_retry; /* Did it get truncated? */ - if (unlikely(page->mapping != mapping)) { + if (unlikely(compound_head(page)->mapping != mapping)) { unlock_page(page); put_page(page); goto retry_find; -- 2.17.1
