diff --git a/mm/filemap.c b/mm/filemap.c
index 30c9c2a63746..81e28722edfa 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2538,18 +2538,19 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
 	struct page *page;
 	int err = 0;
 
+	/* "last_index" is the index of the page beyond the end of the read */
 	last_index = DIV_ROUND_UP(iocb->ki_pos + iter->count, PAGE_SIZE);
 retry:
 	if (fatal_signal_pending(current))
 		return -EINTR;
 
-	filemap_get_read_batch(mapping, index, last_index, pvec);
+	filemap_get_read_batch(mapping, index, last_index - 1, pvec);
 	if (!pagevec_count(pvec)) {
 		if (iocb->ki_flags & IOCB_NOIO)
 			return -EAGAIN;
 		page_cache_sync_readahead(mapping, ra, filp, index,
 				last_index - index);
-		filemap_get_read_batch(mapping, index, last_index, pvec);
+		filemap_get_read_batch(mapping, index, last_index - 1, pvec);
 	}
 	if (!pagevec_count(pvec)) {
 		if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_WAITQ))