Commit c00ddad3 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

writeback: remove bdi_start_writeback() 



bdi_start_writeback() is a thin wrapper on top of
__wb_start_writeback() which is used only by laptop_mode_timer_fn().
This patches removes bdi_start_writeback(), renames
__wb_start_writeback() to wb_start_writeback() and makes
laptop_mode_timer_fn() use it instead.

This doesn't cause any functional difference and will ease making
laptop_mode_timer_fn() cgroup writeback aware.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent ebe41ab0

fs/fs-writeback.c

+25 −43
Original line number Diff line number Diff line
@@ -184,33 +184,6 @@ out_unlock: 
	spin_unlock_bh(&wb->work_lock);

}



static void __wb_start_writeback(struct bdi_writeback *wb, long nr_pages,

				 bool range_cyclic, enum wb_reason reason)

{

	struct wb_writeback_work *work;



	if (!wb_has_dirty_io(wb))

		return;



	/*

	 * This is WB_SYNC_NONE writeback, so if allocation fails just

	 * wakeup the thread for old dirty data writeback

	 */

	work = kzalloc(sizeof(*work), GFP_ATOMIC);

	if (!work) {

		trace_writeback_nowork(wb->bdi);

		wb_wakeup(wb);

		return;

	}



	work->sync_mode	= WB_SYNC_NONE;

	work->nr_pages	= nr_pages;

	work->range_cyclic = range_cyclic;

	work->reason	= reason;



	wb_queue_work(wb, work);

}



#ifdef CONFIG_CGROUP_WRITEBACK



/**
@@ -240,22 +213,31 @@ EXPORT_SYMBOL_GPL(inode_congested); 


#endif	/* CONFIG_CGROUP_WRITEBACK */



/**

 * bdi_start_writeback - start writeback

 * @bdi: the backing device to write from

 * @nr_pages: the number of pages to write

 * @reason: reason why some writeback work was initiated

 *

 * Description:

 *   This does WB_SYNC_NONE opportunistic writeback. The IO is only

 *   started when this function returns, we make no guarantees on

 *   completion. Caller need not hold sb s_umount semaphore.

 *

 */

void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,

			enum wb_reason reason)

void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,

			bool range_cyclic, enum wb_reason reason)

{

	__wb_start_writeback(&bdi->wb, nr_pages, true, reason);

	struct wb_writeback_work *work;



	if (!wb_has_dirty_io(wb))

		return;



	/*

	 * This is WB_SYNC_NONE writeback, so if allocation fails just

	 * wakeup the thread for old dirty data writeback

	 */

	work = kzalloc(sizeof(*work), GFP_ATOMIC);

	if (!work) {

		trace_writeback_nowork(wb->bdi);

		wb_wakeup(wb);

		return;

	}



	work->sync_mode	= WB_SYNC_NONE;

	work->nr_pages	= nr_pages;

	work->range_cyclic = range_cyclic;

	work->reason	= reason;



	wb_queue_work(wb, work);

}



/**
@@ -1219,7 +1201,7 @@ void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) 


	rcu_read_lock();

	list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)

		__wb_start_writeback(&bdi->wb, nr_pages, false, reason);

		wb_start_writeback(&bdi->wb, nr_pages, false, reason);

	rcu_read_unlock();

}

include/linux/backing-dev.h

+2 −2
Original line number Diff line number Diff line
@@ -25,8 +25,8 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, 
int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);

void bdi_unregister(struct backing_dev_info *bdi);

int __must_check bdi_setup_and_register(struct backing_dev_info *, char *);

void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,

			enum wb_reason reason);

void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,

			bool range_cyclic, enum wb_reason reason);

void bdi_start_background_writeback(struct backing_dev_info *bdi);

void wb_workfn(struct work_struct *work);

void wb_wakeup_delayed(struct bdi_writeback *wb);

mm/page-writeback.c

+2 −2
Original line number Diff line number Diff line
@@ -1729,7 +1729,7 @@ void laptop_mode_timer_fn(unsigned long data) 
	 * threshold

	 */

	if (bdi_has_dirty_io(&q->backing_dev_info))

		bdi_start_writeback(&q->backing_dev_info, nr_pages,

		wb_start_writeback(&q->backing_dev_info.wb, nr_pages, true,

				   WB_REASON_LAPTOP_TIMER);

}

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