From: David Howells dhowells@redhat.com
commit e5a59d308f52bb0052af5790c22173651b187465 upstream.
collapse_file() in khugepaged passes PAGE_SIZE as the number of pages to be read to page_cache_sync_readahead(). The intent was probably to read a single page. Fix it to use the number of pages to the end of the window instead.
Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Reviewed-by: Matthew Wilcox (Oracle) willy@infradead.org Acked-by: Song Liu songliubraving@fb.com Acked-by: Yang Shi shy828301@gmail.com Acked-by: Pankaj Gupta pankaj.gupta.linux@gmail.com Cc: Eric Biggers ebiggers@google.com Link: https://lkml.kernel.org/r/20200903140844.14194-2-willy@infradead.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- mm/khugepaged.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1592,7 +1592,7 @@ static void collapse_file(struct mm_stru xas_unlock_irq(&xas); page_cache_sync_readahead(mapping, &file->f_ra, file, index, - PAGE_SIZE); + end - index); /* drain pagevecs to help isolate_lru_page() */ lru_add_drain(); page = find_lock_page(mapping, index);