Re: [PATCH 4/4] writeback: introduce super_operations->write_metadata

[Jan Kara <jack@suse.cz>]

On Tue 20-09-16 16:57:48, Josef Bacik wrote:
> Now that we have metadata counters in the VM, we need to provide a way to kick
> writeback on dirty metadata.  Introduce super_operations->write_metadata.  This
> allows file systems to deal with writing back any dirty metadata we need based
> on the writeback needs of the system.  Since there is no inode to key off of we
> need a list in the bdi for dirty super blocks to be added.  From there we can
> find any dirty sb's on the bdi we are currently doing writeback on and call into
> their ->write_metadata callback.
> 
> Signed-off-by: Josef Bacik <jbacik@fb.com>
> ---
>  fs/fs-writeback.c                | 72 ++++++++++++++++++++++++++++++++++++----
>  fs/super.c                       |  7 ++++
>  include/linux/backing-dev-defs.h |  2 ++
>  include/linux/fs.h               |  4 +++
>  mm/backing-dev.c                 |  2 ++
>  5 files changed, 81 insertions(+), 6 deletions(-)
> 

...

> +	if (!done && sb->s_op->write_metadata) {
> +		spin_unlock(&wb->list_lock);
> +		wrote += writeback_sb_metadata(sb, wb, work);
> +		spin_unlock(&wb->list_lock);
		^^^
		spin_lock();

Otherwise the patch looks good to me. So feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

after fixing the above.

								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR