From 2a7d5559b346574057dce4672d1ed9aaa9d1e685 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 31 Jul 2012 09:08:15 +0200 Subject: [PATCH] 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 Signed-off-by: NeilBrown Signed-off-by: Jens Axboe --- block/blk-core.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 177ddcf356e6..35bf4fe8234c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2913,17 +2913,16 @@ 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); - list_splice_init(&plug->cb_list, &callbacks); - - while (!list_empty(&callbacks)) { - struct blk_plug_cb *cb = list_first_entry(&callbacks, + while (!list_empty(&callbacks)) { + struct blk_plug_cb *cb = list_first_entry(&callbacks, struct blk_plug_cb, list); - list_del(&cb->list); - cb->callback(cb); + list_del(&cb->list); + cb->callback(cb); + } } }