writeback: provide a wakeup_flusher_threads_bdi()

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.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Chris Mason <clm@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2017-09-28 11:26:59 -06:00
parent 47410d88f6
commit 595043e5f9
2 changed files with 31 additions and 10 deletions

View File

@ -1946,6 +1946,33 @@ void wb_workfn(struct work_struct *work)
current->flags &= ~PF_SWAPWRITE;
}
/*
* 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),
reason);
}
void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
enum wb_reason reason)
{
long nr_pages = get_nr_dirty_pages();
rcu_read_lock();
__wakeup_flusher_threads_bdi(bdi, nr_pages, reason);
rcu_read_unlock();
}
/*
* Wakeup the flusher threads to start writeback of all currently dirty pages
*/
@ -1963,16 +1990,8 @@ void wakeup_flusher_threads(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),
reason);
}
list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
__wakeup_flusher_threads_bdi(bdi, nr_pages, reason);
rcu_read_unlock();
}

View File

@ -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(enum wb_reason reason);
void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,
enum wb_reason reason);
void inode_wait_for_writeback(struct inode *inode);
/* writeback.h requires fs.h; it, too, is not included from here. */