Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754980AbbKXSgd (ORCPT ); Tue, 24 Nov 2015 13:36:33 -0500 Received: from mail-lf0-f53.google.com ([209.85.215.53]:35043 "EHLO mail-lf0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754412AbbKXSgb (ORCPT ); Tue, 24 Nov 2015 13:36:31 -0500 Message-ID: <5654AE2D.2080802@lightnvm.io> Date: Tue, 24 Nov 2015 19:36:29 +0100 From: Matias User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Wenwei Tao CC: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Subject: Re: [PATCH] lightnvm: missing nvm_lock acquire References: <1448378697-2532-1-git-send-email-ww.tao0320@gmail.com> In-Reply-To: <1448378697-2532-1-git-send-email-ww.tao0320@gmail.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1784 Lines: 57 On 11/24/2015 04:24 PM, Wenwei Tao wrote: > To avoid race conditions, traverse dev, media manager, > and targeet lists and also register, unregister entries > to/from them, should be always under the nvm_lock control. > > Signed-off-by: Wenwei Tao > --- > drivers/lightnvm/core.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c > index f659e60..39aec3a 100644 > --- a/drivers/lightnvm/core.c > +++ b/drivers/lightnvm/core.c > @@ -333,19 +333,19 @@ EXPORT_SYMBOL(nvm_register); > > void nvm_unregister(char *disk_name) > { > + down_write(&nvm_lock); > struct nvm_dev *dev = nvm_find_nvm_dev(disk_name); In nvm_find_nvm_dev, can we instead replace it with list_for_each_entry_safe. Then we are sure that we won't hit a missing element, and will make the other cases significantly cleaner. > > if (!dev) { > pr_err("nvm: could not find device %s to unregister\n", > disk_name); > + up_write(&nvm_lock); > return; > } > > - nvm_exit(dev); > - > - down_write(&nvm_lock); > list_del(&dev->devices); > up_write(&nvm_lock); > + nvm_exit(dev); > } > EXPORT_SYMBOL(nvm_unregister); > > @@ -365,12 +365,15 @@ static int nvm_create_target(struct nvm_dev *dev, > void *targetdata; > int ret = 0; > > + down_write(&nvm_lock); > if (!dev->mt) { > /* register with device with a supported NVM manager */ > list_for_each_entry(mt, &nvm_mgrs, list) { Same with this one? -- 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/