[PATCH 13/15] md/raid1: clean up sync IO size calculation in raid1_sync_request

[linan666]

From: Li Nan <linan122@xxxxxxxxxx>

Use 'nr_sectors' directly for sync IO size calculation. Prepare folio
allocation failure fallback.

No functional changes.

Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
 drivers/md/raid1.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 38f86de45dea..2be2277d4e7e 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2970,21 +2970,19 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
 		max_sector = mddev->resync_max; /* Don't do IO beyond here */
 	if (max_sector > sector_nr + good_sectors)
 		max_sector = sector_nr + good_sectors;
-	nr_sectors = 0;
 	do {
 		struct folio *folio;
-		int len = RESYNC_BLOCK_SIZE;
-		if (sector_nr + (len>>9) > max_sector)
-			len = (max_sector - sector_nr) << 9;
-		if (len == 0)
+
+		nr_sectors = max_sector - sector_nr;
+		if (nr_sectors == 0)
 			break;
 		if (!md_bitmap_start_sync(mddev, sector_nr,
 					  &sync_blocks, still_degraded) &&
 		    !conf->fullsync &&
 		    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
 			break;
-		if ((len >> 9) > sync_blocks)
-			len = sync_blocks<<9;
+		if (nr_sectors > sync_blocks)
+			nr_sectors = sync_blocks;
 
 		for (i = 0 ; i < conf->raid_disks * 2; i++) {
 			struct resync_folio *rf;
@@ -2998,11 +2996,10 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
 				 * won't fail because the vec table is big
 				 * enough to hold all these pages
 				 */
-				bio_add_folio_nofail(bio, folio, len, 0);
+				bio_add_folio_nofail(bio, folio, nr_sectors << 9, 0);
 			}
 		}
-		nr_sectors += len>>9;
-		sector_nr += len>>9;
+		sector_nr += nr_sectors;
 	} while (0);
 
 	r1_bio->sectors = nr_sectors;
-- 
2.39.2