On Tue 19-09-17 13:53:03, Jens Axboe wrote:
> Similar to wakeup_flusher_threads(), except that we only wake
> up the flusher threads on the specified backing device.
>
> No functional changes in this patch.
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/fs-writeback.c | 40 ++++++++++++++++++++++++++++++----------
> include/linux/writeback.h | 2 ++
> 2 files changed, 32 insertions(+), 10 deletions(-)
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index 245c430a2e41..03fda0830bf8 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -1947,6 +1947,34 @@ void wb_workfn(struct work_struct *work)
> }
>
> /*
> + * Start writeback of `nr_pages' pages on this bdi. If `nr_pages' is zero,
> + * write back the whole world.
> + */
> +static void __wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
> + long nr_pages, enum wb_reason reason)
> +{
> + struct bdi_writeback *wb;
> +
> + if (!bdi_has_dirty_io(bdi))
> + return;
> +
> + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node)
> + wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages),
> + false, reason);
> +}
> +
> +void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, long nr_pages,
> + enum wb_reason reason)
> +{
> + if (!nr_pages)
> + nr_pages = get_nr_dirty_pages();
> +
> + rcu_read_lock();
> + __wakeup_flusher_threads_bdi(bdi, nr_pages, reason);
> + rcu_read_unlock();
> +}
> +
> +/*
> * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back
> * the whole world.
> */
> @@ -1964,16 +1992,8 @@ void wakeup_flusher_threads(long nr_pages, enum wb_reason reason)
> nr_pages = get_nr_dirty_pages();
>
> rcu_read_lock();
> - list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
> - struct bdi_writeback *wb;
> -
> - if (!bdi_has_dirty_io(bdi))
> - continue;
> -
> - list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node)
> - wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages),
> - false, reason);
> - }
> + list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
> + __wakeup_flusher_threads_bdi(bdi, nr_pages, reason);
> rcu_read_unlock();
> }
>
> diff --git a/include/linux/writeback.h b/include/linux/writeback.h
> index d5815794416c..5a7ed74d1f6f 100644
> --- a/include/linux/writeback.h
> +++ b/include/linux/writeback.h
> @@ -190,6 +190,8 @@ bool try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
> enum wb_reason reason);
> void sync_inodes_sb(struct super_block *);
> void wakeup_flusher_threads(long nr_pages, enum wb_reason reason);
> +void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, long nr_pages,
> + enum wb_reason reason);
> void inode_wait_for_writeback(struct inode *inode);
>
> /* writeback.h requires fs.h; it, too, is not included from here. */
> --
> 2.7.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
