From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: [PATCH 2/1] block: make blk_init_free_list and elevator_init idempotent Date: Tue, 25 May 2010 13:15:15 -0400 Message-ID: <20100525171515.GB10155@redhat.com> References: <1274744795-9825-1-git-send-email-snitzer@redhat.com> <1274744795-9825-3-git-send-email-snitzer@redhat.com> <4BFBB21A.3030105@ct.jp.nec.com> <20100525124912.GA7447@redhat.com> <20100525163455.GA10155@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20100525163455.GA10155@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Jens Axboe Cc: dm-devel@redhat.com, Alasdair Kergon , Kiyoshi Ueda , linux-kernel@vger.kernel.org List-Id: dm-devel.ids blk_init_allocated_queue_node may fail and the caller _could_ retry. Accommodate the unlikely event that blk_init_allocated_queue_node is called on an already initialized (possibly partially) request_queue. Signed-off-by: Mike Snitzer --- block/blk-core.c | 3 +++ block/elevator.c | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index c0179b7..2c208c3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -467,6 +467,9 @@ static int blk_init_free_list(struct request_queue *q) { struct request_list *rl = &q->rq; + if (unlikely(rl->rq_pool)) + return 0; + rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0; rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0; rl->elvpriv = 0; diff --git a/block/elevator.c b/block/elevator.c index 0abce47..923a913 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -242,9 +242,11 @@ int elevator_init(struct request_queue *q, char *name) { struct elevator_type *e = NULL; struct elevator_queue *eq; - int ret = 0; void *data; + if (unlikely(q->elevator)) + return 0; + INIT_LIST_HEAD(&q->queue_head); q->last_merge = NULL; q->end_sector = 0; @@ -284,7 +286,7 @@ int elevator_init(struct request_queue *q, char *name) } elevator_attach(q, eq, data); - return ret; + return 0; } EXPORT_SYMBOL(elevator_init);