From: Yu Kuai <yukuai3@huawei.com>

The parameter is always set to 0 for now, following patches will use
this helper to write llbitmap to underlying disks, allow writing
dirty sectors instead of the whole page.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/md/md-bitmap.c |  3 ++-
 drivers/md/md.c        | 13 +++++++------
 drivers/md/md.h        |  3 ++-
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 4c5067783b7a..a5602cb5d756 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -468,7 +468,8 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
 			return -EINVAL;
 	}
 
-	md_super_write(mddev, rdev, sboff + ps, (int)min(size, bitmap_limit), page);
+	md_super_write(mddev, rdev, sboff + ps, (int)min(size, bitmap_limit),
+		       page, 0);
 	return 0;
 }
 
diff --git a/drivers/md/md.c b/drivers/md/md.c
index ba2b981b017c..4329ecfbe8ff 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1037,7 +1037,8 @@ static void super_written(struct bio *bio)
 }
 
 void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
-		   sector_t sector, int size, struct page *page)
+		   sector_t sector, int size, struct page *page,
+		   unsigned int offset)
 {
 	/* write first size bytes of page to sector of rdev
 	 * Increment mddev->pending_writes before returning
@@ -1062,7 +1063,7 @@ void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
 	atomic_inc(&rdev->nr_pending);
 
 	bio->bi_iter.bi_sector = sector;
-	__bio_add_page(bio, page, size, 0);
+	__bio_add_page(bio, page, size, offset);
 	bio->bi_private = rdev;
 	bio->bi_end_io = super_written;
 
@@ -1673,7 +1674,7 @@ super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
 		num_sectors = (sector_t)(2ULL << 32) - 2;
 	do {
 		md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
-		       rdev->sb_page);
+			       rdev->sb_page, 0);
 	} while (md_super_wait(rdev->mddev) < 0);
 	return num_sectors;
 }
@@ -2322,7 +2323,7 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
 	sb->sb_csum = calc_sb_1_csum(sb);
 	do {
 		md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
-			       rdev->sb_page);
+			       rdev->sb_page, 0);
 	} while (md_super_wait(rdev->mddev) < 0);
 	return num_sectors;
 
@@ -2833,7 +2834,7 @@ void md_update_sb(struct mddev *mddev, int force_change)
 		if (!test_bit(Faulty, &rdev->flags)) {
 			md_super_write(mddev,rdev,
 				       rdev->sb_start, rdev->sb_size,
-				       rdev->sb_page);
+				       rdev->sb_page, 0);
 			pr_debug("md: (write) %pg's sb offset: %llu\n",
 				 rdev->bdev,
 				 (unsigned long long)rdev->sb_start);
@@ -2842,7 +2843,7 @@ void md_update_sb(struct mddev *mddev, int force_change)
 				md_super_write(mddev, rdev,
 					       rdev->badblocks.sector,
 					       rdev->badblocks.size << 9,
-					       rdev->bb_page);
+					       rdev->bb_page, 0);
 				rdev->badblocks.size = 0;
 			}
 
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 135d95ba1ebb..99f6c7a92b48 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -890,7 +890,8 @@ void md_free_cloned_bio(struct bio *bio);
 
 extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);
 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
-			   sector_t sector, int size, struct page *page);
+			   sector_t sector, int size, struct page *page,
+			   unsigned int offset);
 extern int md_super_wait(struct mddev *mddev);
 extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
 		struct page *page, blk_opf_t opf, bool metadata_op);
-- 
2.39.2

On Mon, May 12, 2025 at 09:19:14AM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> The parameter is always set to 0 for now, following patches will use
> this helper to write llbitmap to underlying disks, allow writing
> dirty sectors instead of the whole page.

Givne that there is nothing super-block specific in md_super_write,
maybe use the chance to rename it?

Hi,

在 2025/05/12 12:55, Christoph Hellwig 写道:
> On Mon, May 12, 2025 at 09:19:14AM +0800, Yu Kuai wrote:
>> From: Yu Kuai <yukuai3@huawei.com>
>>
>> The parameter is always set to 0 for now, following patches will use
>> this helper to write llbitmap to underlying disks, allow writing
>> dirty sectors instead of the whole page.
> 
> Givne that there is nothing super-block specific in md_super_write,
> maybe use the chance to rename it?

Ok, how about md_write_metadata()?

Thanks,
Kuai

> 
> .
> 

On Mon, May 12, 2025 at 02:32:28PM +0800, Yu Kuai wrote:
> Ok, how about md_write_metadata()?

Sounds good.