mm: convert swap_page_sector() to swap_folio_sector()

All callers have a folio, so pass it in.  Saves a couple of calls to
compound_head().

Link: https://lkml.kernel.org/r/20231213215842.671461-10-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/swap.h

@@ -493,7 +493,7 @@ struct backing_dev_info;
 extern int init_swap_address_space(unsigned int type, unsigned long nr_pages);
 extern void exit_swap_address_space(unsigned int type);
 extern struct swap_info_struct *get_swap_device(swp_entry_t entry);
-sector_t swap_page_sector(struct page *page);
+sector_t swap_folio_sector(struct folio *folio);
 
 static inline void put_swap_device(struct swap_info_struct *si)
 {

mm/page_io.c

@@ -334,7 +334,7 @@ static void swap_writepage_bdev_sync(struct folio *folio,
 
 	bio_init(&bio, sis->bdev, &bv, 1,
 		 REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc));
-	bio.bi_iter.bi_sector = swap_page_sector(&folio->page);
+	bio.bi_iter.bi_sector = swap_folio_sector(folio);
 	bio_add_folio_nofail(&bio, folio, folio_size(folio), 0);
 
 	bio_associate_blkg_from_page(&bio, folio);
@@ -355,7 +355,7 @@ static void swap_writepage_bdev_async(struct folio *folio,
 	bio = bio_alloc(sis->bdev, 1,
 			REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc),
 			GFP_NOIO);
-	bio->bi_iter.bi_sector = swap_page_sector(&folio->page);
+	bio->bi_iter.bi_sector = swap_folio_sector(folio);
 	bio->bi_end_io = end_swap_bio_write;
 	bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
 
@@ -461,7 +461,7 @@ static void swap_readpage_bdev_sync(struct folio *folio,
 	struct bio bio;
 
 	bio_init(&bio, sis->bdev, &bv, 1, REQ_OP_READ);
-	bio.bi_iter.bi_sector = swap_page_sector(&folio->page);
+	bio.bi_iter.bi_sector = swap_folio_sector(folio);
 	bio_add_folio_nofail(&bio, folio, folio_size(folio), 0);
 	/*
 	 * Keep this task valid during swap readpage because the oom killer may
@@ -480,7 +480,7 @@ static void swap_readpage_bdev_async(struct folio *folio,
 	struct bio *bio;
 
 	bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
-	bio->bi_iter.bi_sector = swap_page_sector(&folio->page);
+	bio->bi_iter.bi_sector = swap_folio_sector(folio);
 	bio->bi_end_io = end_swap_bio_read;
 	bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
 	count_vm_event(PSWPIN);

mm/swapfile.c

@@ -227,14 +227,14 @@ offset_to_swap_extent(struct swap_info_struct *sis, unsigned long offset)
 	BUG();
 }
 
-sector_t swap_page_sector(struct page *page)
+sector_t swap_folio_sector(struct folio *folio)
 {
-	struct swap_info_struct *sis = page_swap_info(page);
+	struct swap_info_struct *sis = swp_swap_info(folio->swap);
 	struct swap_extent *se;
 	sector_t sector;
 	pgoff_t offset;
 
-	offset = __page_file_index(page);
+	offset = swp_offset(folio->swap);
 	se = offset_to_swap_extent(sis, offset);
 	sector = se->start_block + (offset - se->start_page);
 	return sector << (PAGE_SHIFT - 9);