Commit 2a7d5559 authored Jul 31, 2012 by Shaohua Li Committed by Jens Axboe Jul 31, 2012

block: stack unplug



MD raid1 prepares to dispatch request in unplug callback. If make_request in
low level queue also uses unplug callback to dispatch request, the low level
queue's unplug callback will not be called. Recheck the callback list helps
this case.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 9cbb1750

block/blk-core.c

+7 −8

Original line number	Diff line number	Diff line
		@@ -2913,9 +2913,7 @@ static void flush_plug_callbacks(struct blk_plug *plug)
		{
		LIST_HEAD(callbacks);

		if (list_empty(&plug->cb_list))
		return;

		while (!list_empty(&plug->cb_list)) {
		list_splice_init(&plug->cb_list, &callbacks);

		while (!list_empty(&callbacks)) {
		@@ -2926,6 +2924,7 @@ static void flush_plug_callbacks(struct blk_plug *plug)
		cb->callback(cb);
		}
		}
		}

		struct blk_plug_cb blk_check_plugged(blk_plug_cb_fn unplug, void data,
		int size)