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

David Howells
2021-09-24T17:18:33Z

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@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Christoph Hellwig <hch@lst.de>
cc: Jens Axboe <axboe@kernel.dk>
cc: Darrick J. Wong <djwong@kernel.org>
cc: linux-xfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---

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)