Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756952Ab0FCRfG (ORCPT ); Thu, 3 Jun 2010 13:35:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58301 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756551Ab0FCRfD (ORCPT ); Thu, 3 Jun 2010 13:35:03 -0400 Date: Thu, 3 Jun 2010 13:34:52 -0400 From: Mike Snitzer To: Jens Axboe Cc: Kiyoshi Ueda , dm-devel@redhat.com, linux-kernel@vger.kernel.org, Alasdair Kergon Subject: [PATCH v4] block: avoid unconditionally freeing previously allocated request_queue Message-ID: <20100603173452.GC6730@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> <20100526045219.GB24702@redhat.com> <20100603165809.GA6730@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100603165809.GA6730@redhat.com> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2427 Lines: 72 block: avoid unconditionally freeing previously allocated request_queue On blk_init_allocated_queue_node failure, only free the request_queue if it is wasn't previously allocated outside the block layer (e.g. blk_init_queue_node was blk_init_allocated_queue_node caller). This addresses an interface bug introduced by the following commit: 01effb0 block: allow initialization of previously allocated request_queue Otherwise the request_queue may be free'd out from underneath a caller that is managing the request_queue directly (e.g. caller uses blk_alloc_queue + blk_init_allocated_queue_node). Signed-off-by: Mike Snitzer --- block/blk-core.c | 17 +++++++++++------ 1 files changed, 11 insertions(+), 6 deletions(-) v4: eliminate potential for NULL pointer in call to blk_cleanup_queue v3: leverage fact that blk_cleanup_queue will properly free all memory associated with a request_queue (e.g.: q->rq_pool and q->elevator) diff --git a/block/blk-core.c b/block/blk-core.c index 3bc5579..826d070 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -570,9 +570,17 @@ EXPORT_SYMBOL(blk_init_queue); struct request_queue * blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id) { - struct request_queue *q = blk_alloc_queue_node(GFP_KERNEL, node_id); + struct request_queue *uninit_q, *q; - return blk_init_allocated_queue_node(q, rfn, lock, node_id); + uninit_q = blk_alloc_queue_node(GFP_KERNEL, node_id); + if (!uninit_q) + return NULL; + + q = blk_init_allocated_queue_node(uninit_q, rfn, lock, node_id); + if (!q) + blk_cleanup_queue(uninit_q); + + return q; } EXPORT_SYMBOL(blk_init_queue_node); @@ -592,10 +600,8 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn, return NULL; q->node = node_id; - if (blk_init_free_list(q)) { - kmem_cache_free(blk_requestq_cachep, q); + if (blk_init_free_list(q)) return NULL; - } q->request_fn = rfn; q->prep_rq_fn = NULL; @@ -618,7 +624,6 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn, return q; } - blk_put_queue(q); return NULL; } EXPORT_SYMBOL(blk_init_allocated_queue_node); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/