Commit 88b996cd authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: cleanup the block plug helper functions 



It's a bit of a mess currently. task->plug is being cleared
and reset in __blk_finish_plug(), and blk_finish_plug() is
testing for a NULL plug which cannot happen even from schedule()
anymore since it uses blk_needs_flush_plug() to determine
whether to call into this function at all.

So get rid of some of the cruft.

Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 80656b67

block/blk-core.c

+6 −18
Original line number Diff line number Diff line
@@ -2671,7 +2671,7 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth) 
		q->unplugged_fn(q);

}



static void flush_plug_list(struct blk_plug *plug)

void blk_flush_plug_list(struct blk_plug *plug)

{

	struct request_queue *q;

	unsigned long flags;
@@ -2733,28 +2733,16 @@ static void flush_plug_list(struct blk_plug *plug) 


	local_irq_restore(flags);

}



static void __blk_finish_plug(struct task_struct *tsk, struct blk_plug *plug)

{

	flush_plug_list(plug);



	if (plug == tsk->plug)

		tsk->plug = NULL;

}

EXPORT_SYMBOL(blk_flush_plug_list);



void blk_finish_plug(struct blk_plug *plug)

{

	if (plug)

		__blk_finish_plug(current, plug);

}

EXPORT_SYMBOL(blk_finish_plug);

	blk_flush_plug_list(plug);



void __blk_flush_plug(struct task_struct *tsk, struct blk_plug *plug)

{

	__blk_finish_plug(tsk, plug);

	tsk->plug = plug;

	if (plug == current->plug)

		current->plug = NULL;

}

EXPORT_SYMBOL(__blk_flush_plug);

EXPORT_SYMBOL(blk_finish_plug);



int __init blk_dev_init(void)

{

include/linux/blkdev.h

+3 −3
Original line number Diff line number Diff line
@@ -865,14 +865,14 @@ struct blk_plug { 


extern void blk_start_plug(struct blk_plug *);

extern void blk_finish_plug(struct blk_plug *);

extern void __blk_flush_plug(struct task_struct *, struct blk_plug *);

extern void blk_flush_plug_list(struct blk_plug *);



static inline void blk_flush_plug(struct task_struct *tsk)

{

	struct blk_plug *plug = tsk->plug;



	if (unlikely(plug))

		__blk_flush_plug(tsk, plug);

	if (plug)

		blk_flush_plug_list(plug);

}



static inline bool blk_needs_flush_plug(struct task_struct *tsk)

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