writeback: inline allocation failure handling in bdi_alloc_queue_work()

This gets rid of work == NULL in bdi_queue_work() and puts the
OOM handling where it belongs.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2009-09-13 20:07:36 +02:00
parent cfc4ba5365
commit bcddc3f01c

View file

@ -149,21 +149,19 @@ static void wb_clear_pending(struct bdi_writeback *wb, struct bdi_work *work)
static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work)
{
if (work) {
work->seen = bdi->wb_mask;
BUG_ON(!work->seen);
atomic_set(&work->pending, bdi->wb_cnt);
BUG_ON(!bdi->wb_cnt);
work->seen = bdi->wb_mask;
BUG_ON(!work->seen);
atomic_set(&work->pending, bdi->wb_cnt);
BUG_ON(!bdi->wb_cnt);
/*
* Make sure stores are seen before it appears on the list
*/
smp_mb();
/*
* Make sure stores are seen before it appears on the list
*/
smp_mb();
spin_lock(&bdi->wb_lock);
list_add_tail_rcu(&work->list, &bdi->work_list);
spin_unlock(&bdi->wb_lock);
}
spin_lock(&bdi->wb_lock);
list_add_tail_rcu(&work->list, &bdi->work_list);
spin_unlock(&bdi->wb_lock);
/*
* If the default thread isn't there, make sure we add it. When
@ -175,14 +173,12 @@ static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work)
struct bdi_writeback *wb = &bdi->wb;
/*
* If we failed allocating the bdi work item, wake up the wb
* thread always. As a safety precaution, it'll flush out
* everything
* End work now if this wb has no dirty IO pending. Otherwise
* wakeup the handling thread
*/
if (!wb_has_dirty_io(wb)) {
if (work)
wb_clear_pending(wb, work);
} else if (wb->task)
if (!wb_has_dirty_io(wb))
wb_clear_pending(wb, work);
else if (wb->task)
wake_up_process(wb->task);
}
}
@ -202,11 +198,20 @@ static void bdi_alloc_queue_work(struct backing_dev_info *bdi,
{
struct bdi_work *work;
/*
* This is WB_SYNC_NONE writeback, so if allocation fails just
* wakeup the thread for old dirty data writeback
*/
work = kmalloc(sizeof(*work), GFP_ATOMIC);
if (work)
if (work) {
bdi_work_init(work, wbc);
bdi_queue_work(bdi, work);
} else {
struct bdi_writeback *wb = &bdi->wb;
bdi_queue_work(bdi, work);
if (wb->task)
wake_up_process(wb->task);
}
}
void bdi_start_writeback(struct writeback_control *wbc)