From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Tue, 25 Aug 2020 07:09:40 +0000 Subject: Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()' Message-Id: <20200825070940.GD29268@lst.de> List-Id: References: <20200821075819.152474-1-christophe.jaillet@wanadoo.fr> <823cd0d7-1688-7d11-1e9b-2de29b6065a6@grimberg.me> <20200824211630.GA1490518@dhcp-10-100-145-180.wdl.wdc.com> In-Reply-To: <20200824211630.GA1490518@dhcp-10-100-145-180.wdl.wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Keith Busch Cc: Sagi Grimberg , chaitanya.kulkarni@wdc.com, kernel-janitors@vger.kernel.org, james.smart@broadcom.com, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Christophe JAILLET , hch@lst.de On Mon, Aug 24, 2020 at 02:16:30PM -0700, Keith Busch wrote: > On Mon, Aug 24, 2020 at 01:00:11PM -0700, Sagi Grimberg wrote: > > > The way 'spin_lock()' and 'spin_lock_irqsave()' are used is not consistent > > > in this function. > > > > > > Use 'spin_lock_irqsave()' also here, as there is no guarantee that > > > interruptions are disabled at that point, according to surrounding code. > > > > > > Fixes: a97ec51b37ef ("nvmet_fc: Rework target side abort handling") > > > Signed-off-by: Christophe JAILLET > > > --- > > > Not tested, only based on what looks logical to me according to > > > surrounding code > > > --- > > > drivers/nvme/target/fc.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c > > > index 55bafd56166a..e6861cc10e7d 100644 > > > --- a/drivers/nvme/target/fc.c > > > +++ b/drivers/nvme/target/fc.c > > > @@ -2342,9 +2342,9 @@ nvmet_fc_fod_op_done(struct nvmet_fc_fcp_iod *fod) > > > return; > > > if (fcpreq->fcp_error || > > > fcpreq->transferred_length != fcpreq->transfer_length) { > > > - spin_lock(&fod->flock); > > > + spin_lock_irqsave(&fod->flock, flags); > > > fod->abort = true; > > > - spin_unlock(&fod->flock); > > > + spin_unlock_irqrestore(&fod->flock, flags); > > > nvmet_req_complete(&fod->req, NVME_SC_INTERNAL); > > > return; > > > > > > > James, can I get a reviewed-by from you on this? > > afaics, the lock just serializes single writes, in which > WRITE/READ_ONCE() can handle that without a lock, right? It synchronizes a few fields, sometimes taken over multiple updates. 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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kAT5V-0001Qj-Ag; Tue, 25 Aug 2020 07:09:45 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kAT5T-0001Ps-1J for linux-nvme@lists.infradead.org; Tue, 25 Aug 2020 07:09:44 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id B38B568BEB; Tue, 25 Aug 2020 09:09:40 +0200 (CEST) Date: Tue, 25 Aug 2020 09:09:40 +0200 From: Christoph Hellwig To: Keith Busch Subject: Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()' Message-ID: <20200825070940.GD29268@lst.de> References: <20200821075819.152474-1-christophe.jaillet@wanadoo.fr> <823cd0d7-1688-7d11-1e9b-2de29b6065a6@grimberg.me> <20200824211630.GA1490518@dhcp-10-100-145-180.wdl.wdc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200824211630.GA1490518@dhcp-10-100-145-180.wdl.wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200825_030943_218276_0095FFB7 X-CRM114-Status: GOOD ( 23.60 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sagi Grimberg , chaitanya.kulkarni@wdc.com, kernel-janitors@vger.kernel.org, james.smart@broadcom.com, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Christophe JAILLET , hch@lst.de Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Aug 24, 2020 at 02:16:30PM -0700, Keith Busch wrote: > On Mon, Aug 24, 2020 at 01:00:11PM -0700, Sagi Grimberg wrote: > > > The way 'spin_lock()' and 'spin_lock_irqsave()' are used is not consistent > > > in this function. > > > > > > Use 'spin_lock_irqsave()' also here, as there is no guarantee that > > > interruptions are disabled at that point, according to surrounding code. > > > > > > Fixes: a97ec51b37ef ("nvmet_fc: Rework target side abort handling") > > > Signed-off-by: Christophe JAILLET > > > --- > > > Not tested, only based on what looks logical to me according to > > > surrounding code > > > --- > > > drivers/nvme/target/fc.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c > > > index 55bafd56166a..e6861cc10e7d 100644 > > > --- a/drivers/nvme/target/fc.c > > > +++ b/drivers/nvme/target/fc.c > > > @@ -2342,9 +2342,9 @@ nvmet_fc_fod_op_done(struct nvmet_fc_fcp_iod *fod) > > > return; > > > if (fcpreq->fcp_error || > > > fcpreq->transferred_length != fcpreq->transfer_length) { > > > - spin_lock(&fod->flock); > > > + spin_lock_irqsave(&fod->flock, flags); > > > fod->abort = true; > > > - spin_unlock(&fod->flock); > > > + spin_unlock_irqrestore(&fod->flock, flags); > > > nvmet_req_complete(&fod->req, NVME_SC_INTERNAL); > > > return; > > > > > > > James, can I get a reviewed-by from you on this? > > afaics, the lock just serializes single writes, in which > WRITE/READ_ONCE() can handle that without a lock, right? It synchronizes a few fields, sometimes taken over multiple updates. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 150BDC433E1 for ; Tue, 25 Aug 2020 07:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6757207FB for ; Tue, 25 Aug 2020 07:09:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729312AbgHYHJp (ORCPT ); Tue, 25 Aug 2020 03:09:45 -0400 Received: from verein.lst.de ([213.95.11.211]:57698 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728936AbgHYHJn (ORCPT ); Tue, 25 Aug 2020 03:09:43 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id B38B568BEB; Tue, 25 Aug 2020 09:09:40 +0200 (CEST) Date: Tue, 25 Aug 2020 09:09:40 +0200 From: Christoph Hellwig To: Keith Busch Cc: Sagi Grimberg , Christophe JAILLET , james.smart@broadcom.com, hch@lst.de, chaitanya.kulkarni@wdc.com, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()' Message-ID: <20200825070940.GD29268@lst.de> References: <20200821075819.152474-1-christophe.jaillet@wanadoo.fr> <823cd0d7-1688-7d11-1e9b-2de29b6065a6@grimberg.me> <20200824211630.GA1490518@dhcp-10-100-145-180.wdl.wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200824211630.GA1490518@dhcp-10-100-145-180.wdl.wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 24, 2020 at 02:16:30PM -0700, Keith Busch wrote: > On Mon, Aug 24, 2020 at 01:00:11PM -0700, Sagi Grimberg wrote: > > > The way 'spin_lock()' and 'spin_lock_irqsave()' are used is not consistent > > > in this function. > > > > > > Use 'spin_lock_irqsave()' also here, as there is no guarantee that > > > interruptions are disabled at that point, according to surrounding code. > > > > > > Fixes: a97ec51b37ef ("nvmet_fc: Rework target side abort handling") > > > Signed-off-by: Christophe JAILLET > > > --- > > > Not tested, only based on what looks logical to me according to > > > surrounding code > > > --- > > > drivers/nvme/target/fc.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c > > > index 55bafd56166a..e6861cc10e7d 100644 > > > --- a/drivers/nvme/target/fc.c > > > +++ b/drivers/nvme/target/fc.c > > > @@ -2342,9 +2342,9 @@ nvmet_fc_fod_op_done(struct nvmet_fc_fcp_iod *fod) > > > return; > > > if (fcpreq->fcp_error || > > > fcpreq->transferred_length != fcpreq->transfer_length) { > > > - spin_lock(&fod->flock); > > > + spin_lock_irqsave(&fod->flock, flags); > > > fod->abort = true; > > > - spin_unlock(&fod->flock); > > > + spin_unlock_irqrestore(&fod->flock, flags); > > > nvmet_req_complete(&fod->req, NVME_SC_INTERNAL); > > > return; > > > > > > > James, can I get a reviewed-by from you on this? > > afaics, the lock just serializes single writes, in which > WRITE/READ_ONCE() can handle that without a lock, right? It synchronizes a few fields, sometimes taken over multiple updates.