btrfs: stop using write_one_page in btrfs_scratch_superblock

write_one_page is an awkward interface that expects the page locked and
->writepage to be implemented.  Replace that by zeroing the signature
bytes and synchronize the block device page using the proper bdev
helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 119dc26ca141cde4fc7d3bd6d3681a3a059f8171..bcfef75b97da0de6315e0ab76da7c03e272a5a79 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2018,23 +2018,22 @@ static void btrfs_scratch_superblock(struct btrfs_fs_info *fs_info,
                                     struct block_device *bdev, int copy_num)
 {
        struct btrfs_super_block *disk_super;
-       struct page *page;
+       const size_t len = sizeof(disk_super->magic);
+       const u64 bytenr = btrfs_sb_offset(copy_num);
        int ret;
 
-       disk_super = btrfs_read_dev_one_super(bdev, copy_num, false);
+       disk_super = btrfs_read_disk_super(bdev, bytenr, bytenr);
        if (IS_ERR(disk_super))
                return;
 
-       memset(&disk_super->magic, 0, sizeof(disk_super->magic));
-       page = virt_to_page(disk_super);
-       set_page_dirty(page);
-       lock_page(page);
-       /* write_on_page() unlocks the page */
-       ret = write_one_page(page);
+       memset(&disk_super->magic, 0, len);
+       folio_mark_dirty(virt_to_folio(disk_super));
+       btrfs_release_disk_super(disk_super);
+
+       ret = sync_blockdev_range(bdev, bytenr, bytenr + len - 1);
        if (ret)
                btrfs_warn(fs_info, "error clearing superblock number %d (%d)",
                        copy_num, ret);
-       btrfs_release_disk_super(disk_super);
 }
 
 void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,