Move the checks for IOCB_NOWAIT and IOCB_WAITQ from the only caller into
generic_file_buffered_read_pagenotuptodate, which simplifies the error
unwinding.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
mm/filemap.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index c717cfe35cc72a..bae5b905aa7bdc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2219,19 +2219,22 @@ static int filemap_readpage(struct kiocb *iocb, struct page *page)
static int generic_file_buffered_read_pagenotuptodate(struct kiocb *iocb,
struct iov_iter *iter, struct page *page, loff_t pos,
- loff_t count)
+ loff_t count, bool first)
{
struct address_space *mapping = iocb->ki_filp->f_mapping;
- int error;
+ int error = -EAGAIN;
+
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ goto put_page;
/*
- * See comment in do_read_cache_page on why
- * wait_on_page_locked is used to avoid unnecessarily
- * serialisations and why it's safe.
+ * See comment in do_read_cache_page on why wait_on_page_locked is used
+ * to avoid unnecessarily serialisations and why it's safe.
*/
if (iocb->ki_flags & IOCB_WAITQ) {
- error = wait_on_page_locked_async(page,
- iocb->ki_waitq);
+ if (!first)
+ goto put_page;
+ error = wait_on_page_locked_async(page, iocb->ki_waitq);
} else {
error = wait_on_page_locked_killable(page);
}
@@ -2376,17 +2379,8 @@ static int generic_file_buffered_read_get_pages(struct kiocb *iocb,
}
if (!PageUptodate(page)) {
- if ((iocb->ki_flags & IOCB_NOWAIT) ||
- ((iocb->ki_flags & IOCB_WAITQ) && i)) {
- for (j = i; j < nr_got; j++)
- put_page(pages[j]);
- nr_got = i;
- err = -EAGAIN;
- break;
- }
-
err = generic_file_buffered_read_pagenotuptodate(iocb,
- iter, page, pg_pos, pg_count);
+ iter, page, pg_pos, pg_count, i == 0);
if (err) {
if (err == AOP_TRUNCATED_PAGE)
err = 0;
--
2.28.0
