Commit 008f75a2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: cleanup the flush plug helpers 



Consolidate the various helpers into a single blk_flush_plug helper that
takes a plk_plug and the from_scheduler bool and switch all callsites to
call it directly.  Checks that the plug is non-NULL must be performed by
the caller, something that most already do anyway.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211020144119.142582-5-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b600455d

block/blk-core.c

+6 −7
Original line number Diff line number Diff line
@@ -1089,7 +1089,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) 
		return 0;



	if (current->plug)

		blk_flush_plug_list(current->plug, false);

		blk_flush_plug(current->plug, false);



	if (blk_queue_enter(q, BLK_MQ_REQ_NOWAIT))

		return 0;
@@ -1637,7 +1637,7 @@ struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data, 
}

EXPORT_SYMBOL(blk_check_plugged);



void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)

void blk_flush_plug(struct blk_plug *plug, bool from_schedule)

{

	if (!list_empty(&plug->cb_list))

		flush_plug_callbacks(plug, from_schedule);
@@ -1659,12 +1659,11 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) 
 */

void blk_finish_plug(struct blk_plug *plug)

{

	if (plug != current->plug)

		return;

	blk_flush_plug_list(plug, false);



	if (plug == current->plug) {

		blk_flush_plug(plug, false);

		current->plug = NULL;

	}

}

EXPORT_SYMBOL(blk_finish_plug);



void blk_io_schedule(void)

fs/fs-writeback.c

+3 −2
Original line number Diff line number Diff line
@@ -1893,7 +1893,8 @@ static long writeback_sb_inodes(struct super_block *sb, 
			 * unplug, so get our IOs out the door before we

			 * give up the CPU.

			 */

			blk_flush_plug(current);

			if (current->plug)

				blk_flush_plug(current->plug, false);

			cond_resched();

		}
@@ -2291,7 +2292,7 @@ void wakeup_flusher_threads(enum wb_reason reason) 
	 * If we are expecting writeback progress we must submit plugged IO.

	 */

	if (blk_needs_flush_plug(current))

		blk_schedule_flush_plug(current);

		blk_flush_plug(current->plug, true);



	rcu_read_lock();

	list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)

include/linux/blkdev.h

+4 −25
Original line number Diff line number Diff line
@@ -725,9 +725,8 @@ extern void blk_set_queue_dying(struct request_queue *); 
 * as the lock contention for request_queue lock is reduced.

 *

 * It is ok not to disable preemption when adding the request to the plug list

 * or when attempting a merge, because blk_schedule_flush_list() will only flush

 * the plug list when the task sleeps by itself. For details, please see

 * schedule() where blk_schedule_flush_plug() is called.

 * or when attempting a merge. For details, please see schedule() where

 * blk_flush_plug() is called.

 */

struct blk_plug {

	struct request *mq_list; /* blk-mq requests */
@@ -757,23 +756,8 @@ extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 
extern void blk_start_plug(struct blk_plug *);

extern void blk_start_plug_nr_ios(struct blk_plug *, unsigned short);

extern void blk_finish_plug(struct blk_plug *);

extern void blk_flush_plug_list(struct blk_plug *, bool);



static inline void blk_flush_plug(struct task_struct *tsk)

{

	struct blk_plug *plug = tsk->plug;



	if (plug)

		blk_flush_plug_list(plug, false);

}



static inline void blk_schedule_flush_plug(struct task_struct *tsk)

{

	struct blk_plug *plug = tsk->plug;



	if (plug)

		blk_flush_plug_list(plug, true);

}

void blk_flush_plug(struct blk_plug *plug, bool from_schedule);



static inline bool blk_needs_flush_plug(struct task_struct *tsk)

{
@@ -802,15 +786,10 @@ static inline void blk_finish_plug(struct blk_plug *plug) 
{

}



static inline void blk_flush_plug(struct task_struct *task)

{

}



static inline void blk_schedule_flush_plug(struct task_struct *task)

static inline void blk_flush_plug(struct blk_plug *plug, bool async)

{

}





static inline bool blk_needs_flush_plug(struct task_struct *tsk)

{

	return false;

kernel/sched/core.c

+3 −2
Original line number Diff line number Diff line
@@ -6343,7 +6343,7 @@ static inline void sched_submit_work(struct task_struct *tsk) 
	 * make sure to submit it to avoid deadlocks.

	 */

	if (blk_needs_flush_plug(tsk))

		blk_schedule_flush_plug(tsk);

		blk_flush_plug(tsk->plug, true);

}



static void sched_update_worker(struct task_struct *tsk)
@@ -8354,7 +8354,8 @@ int io_schedule_prepare(void) 
	int old_iowait = current->in_iowait;



	current->in_iowait = 1;

	blk_schedule_flush_plug(current);

	if (current->plug)

		blk_flush_plug(current->plug, true);



	return old_iowait;

}