[PATCH AUTOSEL 6.1 15/35] btrfs: stop using write_one_page in btrfs_scratch_superblock

From: Sasha Levin
Date: Tue Jan 24 2023 - 08:43:02 EST


From: Christoph Hellwig <hch@xxxxxx>

[ Upstream commit 26ecf243e407be54807ad67210f7e83b9fad71ea ]

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@xxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/btrfs/volumes.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 8fd14dc7f667..36bb664a25a2 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2021,23 +2021,22 @@ 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,
--
2.39.0