1 files changed, 98 insertions, 85 deletions

diff --git a/mm/page_io.c b/mm/page_io.c
index 233f6e6eb1c5..87b682d18850 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -18,7 +18,6 @@
 #include <linux/swap.h>
 #include <linux/bio.h>
 #include <linux/swapops.h>
-#include <linux/buffer_head.h>
 #include <linux/writeback.h>
 #include <linux/frontswap.h>
 #include <linux/blkdev.h>
@@ -28,7 +27,7 @@
 #include <linux/delayacct.h>
 #include "swap.h"
 
-static void end_swap_bio_write(struct bio *bio)
+static void __end_swap_bio_write(struct bio *bio)
 {
 	struct page *page = bio_first_page_all(bio);
 
@@ -49,13 +48,17 @@ static void end_swap_bio_write(struct bio *bio)
 		ClearPageReclaim(page);
 	}
 	end_page_writeback(page);
+}
+
+static void end_swap_bio_write(struct bio *bio)
+{
+	__end_swap_bio_write(bio);
 	bio_put(bio);
 }
 
-static void end_swap_bio_read(struct bio *bio)
+static void __end_swap_bio_read(struct bio *bio)
 {
 	struct page *page = bio_first_page_all(bio);
-	struct task_struct *waiter = bio->bi_private;
 
 	if (bio->bi_status) {
 		SetPageError(page);
@@ -63,18 +66,16 @@ static void end_swap_bio_read(struct bio *bio)
 		pr_alert_ratelimited("Read-error on swap-device (%u:%u:%llu)\n",
 				     MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 				     (unsigned long long)bio->bi_iter.bi_sector);
-		goto out;
+	} else {
+		SetPageUptodate(page);
 	}
-
-	SetPageUptodate(page);
-out:
 	unlock_page(page);
-	WRITE_ONCE(bio->bi_private, NULL);
+}
+
+static void end_swap_bio_read(struct bio *bio)
+{
+	__end_swap_bio_read(bio);
 	bio_put(bio);
-	if (waiter) {
-		blk_wake_io_task(waiter);
-		put_task_struct(waiter);
-	}
 }
 
 int generic_swapfile_activate(struct swap_info_struct *sis,
@@ -181,11 +182,11 @@ bad_bmap:
 int swap_writepage(struct page *page, struct writeback_control *wbc)
 {
 	struct folio *folio = page_folio(page);
-	int ret = 0;
+	int ret;
 
 	if (folio_free_swap(folio)) {
 		folio_unlock(folio);
-		goto out;
+		return 0;
 	}
 	/*
 	 * Arch code may have to preserve more data than just the page
@@ -195,17 +196,16 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
 	if (ret) {
 		folio_mark_dirty(folio);
 		folio_unlock(folio);
-		goto out;
+		return ret;
 	}
 	if (frontswap_store(&folio->page) == 0) {
 		folio_start_writeback(folio);
 		folio_unlock(folio);
 		folio_end_writeback(folio);
-		goto out;
+		return 0;
 	}
-	ret = __swap_writepage(&folio->page, wbc);
-out:
-	return ret;
+	__swap_writepage(&folio->page, wbc);
+	return 0;
 }
 
 static inline void count_swpout_vm_event(struct page *page)
@@ -292,7 +292,7 @@ static void sio_write_complete(struct kiocb *iocb, long ret)
 	mempool_free(sio, sio_pool);
 }
 
-static int swap_writepage_fs(struct page *page, struct writeback_control *wbc)
+static void swap_writepage_fs(struct page *page, struct writeback_control *wbc)
 {
 	struct swap_iocb *sio = NULL;
 	struct swap_info_struct *sis = page_swap_info(page);
@@ -327,30 +327,33 @@ static int swap_writepage_fs(struct page *page, struct writeback_control *wbc)
 	}
 	if (wbc->swap_plug)
 		*wbc->swap_plug = sio;
-
-	return 0;
 }
 
-int __swap_writepage(struct page *page, struct writeback_control *wbc)
+static void swap_writepage_bdev_sync(struct page *page,
+		struct writeback_control *wbc, struct swap_info_struct *sis)
 {
-	struct bio *bio;
-	int ret;
-	struct swap_info_struct *sis = page_swap_info(page);
+	struct bio_vec bv;
+	struct bio bio;
 
-	VM_BUG_ON_PAGE(!PageSwapCache(page), page);
-	/*
-	 * ->flags can be updated non-atomicially (scan_swap_map_slots),
-	 * but that will never affect SWP_FS_OPS, so the data_race
-	 * is safe.
-	 */
-	if (data_race(sis->flags & SWP_FS_OPS))
-		return swap_writepage_fs(page, wbc);
+	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(page);
+	bio_add_page(&bio, page, thp_size(page), 0);
 
-	ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc);
-	if (!ret) {
-		count_swpout_vm_event(page);
-		return 0;
-	}
+	bio_associate_blkg_from_page(&bio, page);
+	count_swpout_vm_event(page);
+
+	set_page_writeback(page);
+	unlock_page(page);
+
+	submit_bio_wait(&bio);
+	__end_swap_bio_write(&bio);
+}
+
+static void swap_writepage_bdev_async(struct page *page,
+		struct writeback_control *wbc, struct swap_info_struct *sis)
+{
+	struct bio *bio;
 
 	bio = bio_alloc(sis->bdev, 1,
 			REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc),
@@ -364,8 +367,24 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc)
 	set_page_writeback(page);
 	unlock_page(page);
 	submit_bio(bio);
+}
 
-	return 0;
+void __swap_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct swap_info_struct *sis = page_swap_info(page);
+
+	VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+	/*
+	 * ->flags can be updated non-atomicially (scan_swap_map_slots),
+	 * but that will never affect SWP_FS_OPS, so the data_race
+	 * is safe.
+	 */
+	if (data_race(sis->flags & SWP_FS_OPS))
+		swap_writepage_fs(page, wbc);
+	else if (sis->flags & SWP_SYNCHRONOUS_IO)
+		swap_writepage_bdev_sync(page, wbc, sis);
+	else
+		swap_writepage_bdev_async(page, wbc, sis);
 }
 
 void swap_write_unplug(struct swap_iocb *sio)
@@ -441,11 +460,41 @@ static void swap_readpage_fs(struct page *page,
 		*plug = sio;
 }
 
-int swap_readpage(struct page *page, bool synchronous,
-		  struct swap_iocb **plug)
+static void swap_readpage_bdev_sync(struct page *page,
+		struct swap_info_struct *sis)
+{
+	struct bio_vec bv;
+	struct bio bio;
+
+	bio_init(&bio, sis->bdev, &bv, 1, REQ_OP_READ);
+	bio.bi_iter.bi_sector = swap_page_sector(page);
+	bio_add_page(&bio, page, thp_size(page), 0);
+	/*
+	 * Keep this task valid during swap readpage because the oom killer may
+	 * attempt to access it in the page fault retry time check.
+	 */
+	get_task_struct(current);
+	count_vm_event(PSWPIN);
+	submit_bio_wait(&bio);
+	__end_swap_bio_read(&bio);
+	put_task_struct(current);
+}
+
+static void swap_readpage_bdev_async(struct page *page,
+		struct swap_info_struct *sis)
 {
 	struct bio *bio;
-	int ret = 0;
+
+	bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
+	bio->bi_iter.bi_sector = swap_page_sector(page);
+	bio->bi_end_io = end_swap_bio_read;
+	bio_add_page(bio, page, thp_size(page), 0);
+	count_vm_event(PSWPIN);
+	submit_bio(bio);
+}
+
+void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug)
+{
 	struct swap_info_struct *sis = page_swap_info(page);
 	bool workingset = PageWorkingset(page);
 	unsigned long pflags;
@@ -469,55 +518,19 @@ int swap_readpage(struct page *page, bool synchronous,
 	if (frontswap_load(page) == 0) {
 		SetPageUptodate(page);
 		unlock_page(page);
-		goto out;
-	}
-
-	if (data_race(sis->flags & SWP_FS_OPS)) {
+	} else if (data_race(sis->flags & SWP_FS_OPS)) {
 		swap_readpage_fs(page, plug);
-		goto out;
-	}
-
-	if (sis->flags & SWP_SYNCHRONOUS_IO) {
-		ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
-		if (!ret) {
-			count_vm_event(PSWPIN);
-			goto out;
-		}
-	}
-
-	ret = 0;
-	bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
-	bio->bi_iter.bi_sector = swap_page_sector(page);
-	bio->bi_end_io = end_swap_bio_read;
-	bio_add_page(bio, page, thp_size(page), 0);
-	/*
-	 * Keep this task valid during swap readpage because the oom killer may
-	 * attempt to access it in the page fault retry time check.
-	 */
-	if (synchronous) {
-		get_task_struct(current);
-		bio->bi_private = current;
-	}
-	count_vm_event(PSWPIN);
-	bio_get(bio);
-	submit_bio(bio);
-	while (synchronous) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		if (!READ_ONCE(bio->bi_private))
-			break;
-
-		blk_io_schedule();
+	} else if (synchronous || (sis->flags & SWP_SYNCHRONOUS_IO)) {
+		swap_readpage_bdev_sync(page, sis);
+	} else {
+		swap_readpage_bdev_async(page, sis);
 	}
-	__set_current_state(TASK_RUNNING);
-	bio_put(bio);
 
-out:
 	if (workingset) {
 		delayacct_thrashing_end(&in_thrashing);
 		psi_memstall_leave(&pflags);
 	}
 	delayacct_swapin_end();
-	return ret;
 }
 
 void __swap_read_unplug(struct swap_iocb *sio)