Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757158AbbEVJGG (ORCPT ); Fri, 22 May 2015 05:06:06 -0400 Received: from mail.linux-iscsi.org ([67.23.28.174]:43737 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757037AbbEVJF7 (ORCPT ); Fri, 22 May 2015 05:05:59 -0400 Message-ID: <1432285557.898.28.camel@haakon3.risingtidesystems.com> Subject: Re: [PATCH-v2 2/9] target/pr: Use atomic bitop for se_dev_entry->pr_reg reservation check From: "Nicholas A. Bellinger" To: Christoph Hellwig Cc: "Nicholas A. Bellinger" , target-devel , linux-scsi , linux-kernel , Hannes Reinecke , Sagi Grimberg , "Paul E. McKenney" Date: Fri, 22 May 2015 02:05:57 -0700 In-Reply-To: <20150522082614.GA24640@lst.de> References: <1432275071-28882-1-git-send-email-nab@daterainc.com> <1432275071-28882-3-git-send-email-nab@daterainc.com> <20150522082614.GA24640@lst.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1585 Lines: 41 On Fri, 2015-05-22 at 10:26 +0200, Christoph Hellwig wrote: > On Fri, May 22, 2015 at 06:11:04AM +0000, Nicholas A. Bellinger wrote: > > + clear_bit(1, &orig->pr_reg); > > Can you call it ->flags and give the bit a meaningful name? The bit is signaling if se_dev_entry has a PR registration active. I don't see how ->flags is a more meaningful name without other bits defined. > > > diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c > > index c0b593a..d29b39c 100644 > > --- a/drivers/target/target_core_pr.c > > +++ b/drivers/target/target_core_pr.c > > @@ -327,9 +327,13 @@ static int core_scsi3_pr_seq_non_holder( > > int we = 0; /* Write Exclusive */ > > int legacy = 0; /* Act like a legacy device and return > > * RESERVATION CONFLICT on some CDBs */ > > + bool registered = false; > > > > rcu_read_lock(); > > se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); > > + if (se_deve) > > + registered = test_bit(1, &se_deve->pr_reg); > > + rcu_read_unlock(); > > It would be good to just sort out the registered and co variables > here before the RCU changes, as in: > > http://git.infradead.org/users/hch/scsi.git/commitdiff/6372d9f62c83acb30d051387c40deb4dbdcaa376 Why not just keep this patch squashed into the relevant commit in the context of the larger RCU conversion..? -- 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/