[PATCH v4 14/18] mm/filemap: Split filemap_readahead out of filemap_get_pages

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

This simplifies the error handling.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
 mm/filemap.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index df755b86a0a7b..f1c5c7d7aae8e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2319,6 +2319,17 @@ static int filemap_create_page(struct file *file,
 	return error;
 }
 
+static int filemap_readahead(struct kiocb *iocb, struct file *file,
+		struct address_space *mapping, struct page *page,
+		pgoff_t last_index)
+{
+	if (iocb->ki_flags & IOCB_NOIO)
+		return -EAGAIN;
+	page_cache_async_readahead(mapping, &file->f_ra, file, page,
+			page->index, last_index - page->index);
+	return 0;
+}
+
 static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
 		struct pagevec *pvec)
 {
@@ -2356,17 +2367,15 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
 got_pages:
 	{
 		struct page *page = pvec->pages[pvec->nr - 1];
-		pgoff_t pg_index = page->index;
 
 		if (PageReadahead(page)) {
-			if (iocb->ki_flags & IOCB_NOIO) {
+			err = filemap_readahead(iocb, filp, mapping, page,
+					last_index);
+			if (err) {
 				put_page(page);
 				pvec->nr--;
-				err = -EAGAIN;
 				goto err;
 			}
-			page_cache_async_readahead(mapping, ra, filp, page,
-					pg_index, last_index - pg_index);
 		}
 
 		if (!PageUptodate(page)) {
-- 
2.29.2