From patchwork Thu Mar 31 02:40:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 8706941 Return-Path: X-Original-To: patchwork-linux-block@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AFE87C0553 for ; Thu, 31 Mar 2016 02:40:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 949B820374 for ; Thu, 31 Mar 2016 02:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F6AB201EF for ; Thu, 31 Mar 2016 02:40:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751579AbcCaCkz (ORCPT ); Wed, 30 Mar 2016 22:40:55 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:35754 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750984AbcCaCky (ORCPT ); Wed, 30 Mar 2016 22:40:54 -0400 Received: by mail-pf0-f196.google.com with SMTP id t66so5677660pfb.2; Wed, 30 Mar 2016 19:40:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Rjo+ItyWja81CbEftCE3aqg0w8IDxfZkZrfyOjcGu2M=; b=CrmPTR8R96ntWLKZoO/dUkmBAhmf1cibZfAEbbbVBRgoPVLnBmL6NrZePuikbYVZQR PQ4nRiAk8UQTpGJnwYgIDdnATHyxKULVjF64HJIRLisjxARzQIZspTMhRVlEhcB9zn9N 3CAlBAYpJZZ9ZWqKFtirKz3G+vj0HHVUcwDUeU5jVQNECTmbT1LB1iN71m4d/3stRp/6 TLbEi/toeVvMxtgHxX4MzWCMaE21Gim1PPmoU/dmRiy+6KHW8enufNdWrRvBpkQBFzgZ LDXpt56bwj+fKfp8O7Mk92c+5vJ4/scFiFbUi4VV9zHJulZfUsQnmAOCpBcVwSq1YNuO OaHA== X-Gm-Message-State: AD7BkJLkJOsxO9MJsY3vnK+/wlViL9k9Xtt+yAyJPv3rjvCoHmwAKDDzQeAJM2LtrXBR5A== X-Received: by 10.98.67.76 with SMTP id q73mr18261536pfa.137.1459392053633; Wed, 30 Mar 2016 19:40:53 -0700 (PDT) Received: from localhost (45-125-195-13.ip4.readyserver.sg. [45.125.195.13]) by smtp.gmail.com with ESMTPSA id r68sm8910963pfb.51.2016.03.30.19.40.51 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Wed, 30 Mar 2016 19:40:52 -0700 (PDT) From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-block@vger.kernel.org, Christoph Hellwig , Naveen Kaje , Ming Lei , Subject: [PATCH v1] block: partition: initialize percpuref before new partition is visiable Date: Thu, 31 Mar 2016 10:40:27 +0800 Message-Id: <1459392027-10266-1-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.9.1 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SBL, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The initialization of partition's percpu_ref should have been done before the new partition is updated to partition table via rcu_assign_pointer(), otherwise the uninitialized percpu_ref may be accessed in data path. This patch fixes this issue reported by Naveen. Reported-by: Naveen Kaje Tested-by: Naveen Kaje Fixes: 6c71013ecb7e2(block: partition: convert percpu ref) Cc: # v4.3+ Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn --- V1: - put 'if' around the actual device_remove_file at the label as suggested by Christoph - make commit log more accurate block/partition-generic.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/block/partition-generic.c b/block/partition-generic.c index 5d87019..54d4be8 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -361,15 +361,17 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, goto out_del; } + err = hd_ref_init(p); + if (err) + goto out_remove_file; + /* everything is up and running, commence */ rcu_assign_pointer(ptbl->part[partno], p); /* suppress uevent if the disk suppresses it */ if (!dev_get_uevent_suppress(ddev)) kobject_uevent(&pdev->kobj, KOBJ_ADD); - - if (!hd_ref_init(p)) - return p; + return p; out_free_info: free_part_info(p); @@ -378,6 +380,9 @@ out_free_stats: out_free: kfree(p); return ERR_PTR(err); +out_remove_file: + if (flags & ADDPART_FLAG_WHOLEDISK) + device_remove_file(pdev, &dev_attr_whole_disk); out_del: kobject_put(p->holder_dir); device_del(pdev);