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: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Christoph Hellwig 2011-04-15 15:20:10 +02:00 committed by Jens Axboe
parent 80656b67b3
commit 88b996cd06
2 changed files with 9 additions and 21 deletions

View file

@ -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;
@ -2733,29 +2733,17 @@ 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);
blk_flush_plug_list(plug);
if (plug == current->plug)
current->plug = NULL;
}
EXPORT_SYMBOL(blk_finish_plug);
void __blk_flush_plug(struct task_struct *tsk, struct blk_plug *plug)
{
__blk_finish_plug(tsk, plug);
tsk->plug = plug;
}
EXPORT_SYMBOL(__blk_flush_plug);
int __init blk_dev_init(void)
{
BUILD_BUG_ON(__REQ_NR_BITS > 8 *

View file

@ -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)