[PATCH v3 3/9] mm: Make swap_readpage() void

[David Howells]

None of the callers of swap_readpage() actually check its return value and,
indeed, the operation may still be in progress, so remove the return value.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: Christoph Hellwig <hch@xxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Darrick J. Wong <djwong@xxxxxxxxxx>
cc: linux-xfs@xxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
cc: linux-mm@xxxxxxxxx
---

 include/linux/swap.h |    2 +-
 mm/page_io.c         |   11 +++--------
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 576d40e33b1f..293eba012d4f 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -416,7 +416,7 @@ extern void kswapd_stop(int nid);
 #include <linux/blk_types.h> /* for bio_end_io_t */
 
 /* linux/mm/page_io.c */
-extern int swap_readpage(struct page *page, bool do_poll);
+void swap_readpage(struct page *page, bool synchronous);
 extern int swap_writepage(struct page *page, struct writeback_control *wbc);
 int __swap_writepage(struct page *page, struct writeback_control *wbc);
 extern int swap_set_page_dirty(struct page *page);
diff --git a/mm/page_io.c b/mm/page_io.c
index afd18f6ec09e..b9fe25101a39 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -352,10 +352,9 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc)
 	return 0;
 }
 
-int swap_readpage(struct page *page, bool synchronous)
+void swap_readpage(struct page *page, bool synchronous)
 {
 	struct bio *bio;
-	int ret = 0;
 	struct swap_info_struct *sis = page_swap_info(page);
 	blk_qc_t qc;
 	struct gendisk *disk;
@@ -382,15 +381,13 @@ int swap_readpage(struct page *page, bool synchronous)
 		struct file *swap_file = sis->swap_file;
 		struct address_space *mapping = swap_file->f_mapping;
 
-		ret = mapping->a_ops->readpage(swap_file, page);
-		if (!ret)
+		if (!mapping->a_ops->readpage(swap_file, page))
 			count_vm_event(PSWPIN);
 		goto out;
 	}
 
 	if (sis->flags & SWP_SYNCHRONOUS_IO) {
-		ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
-		if (!ret) {
+		if (!bdev_read_page(sis->bdev, swap_page_sector(page), page)) {
 			if (trylock_page(page)) {
 				swap_slot_free_notify(page);
 				unlock_page(page);
@@ -401,7 +398,6 @@ int swap_readpage(struct page *page, bool synchronous)
 		}
 	}
 
-	ret = 0;
 	bio = bio_alloc(GFP_KERNEL, 1);
 	bio_set_dev(bio, sis->bdev);
 	bio->bi_opf = REQ_OP_READ;
@@ -435,7 +431,6 @@ int swap_readpage(struct page *page, bool synchronous)
 
 out:
 	psi_memstall_leave(&pflags);
-	return ret;
 }
 
 int swap_set_page_dirty(struct page *page)