kernel-janitors.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
@ 2020-08-21  7:58 Christophe JAILLET
  2020-08-24 20:00 ` Sagi Grimberg
  2020-08-25  7:10 ` Christoph Hellwig
  0 siblings, 2 replies; 5+ messages in thread
From: Christophe JAILLET @ 2020-08-21  7:58 UTC (permalink / raw)
  To: james.smart, hch, sagi, chaitanya.kulkarni
  Cc: Christophe JAILLET, kernel-janitors, linux-kernel, linux-nvme

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 <christophe.jaillet@wanadoo.fr>
---
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;
-- 
2.25.1

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
  2020-08-21  7:58 [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()' Christophe JAILLET
@ 2020-08-24 20:00 ` Sagi Grimberg
  2020-08-24 21:16   ` Keith Busch
  2020-08-25  7:10 ` Christoph Hellwig
  1 sibling, 1 reply; 5+ messages in thread
From: Sagi Grimberg @ 2020-08-24 20:00 UTC (permalink / raw)
  To: Christophe JAILLET, james.smart, hch, chaitanya.kulkarni
  Cc: kernel-janitors, linux-kernel, linux-nvme

> 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 <christophe.jaillet@wanadoo.fr>
> ---
> 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?

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
  2020-08-24 20:00 ` Sagi Grimberg
@ 2020-08-24 21:16   ` Keith Busch
  2020-08-25  7:09     ` Christoph Hellwig
  0 siblings, 1 reply; 5+ messages in thread
From: Keith Busch @ 2020-08-24 21:16 UTC (permalink / raw)
  To: Sagi Grimberg
  Cc: chaitanya.kulkarni, kernel-janitors, linux-kernel, linux-nvme,
	james.smart, Christophe JAILLET, hch

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 <christophe.jaillet@wanadoo.fr>
> > ---
> > 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?

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
  2020-08-24 21:16   ` Keith Busch
@ 2020-08-25  7:09     ` Christoph Hellwig
  0 siblings, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2020-08-25  7:09 UTC (permalink / raw)
  To: Keith Busch
  Cc: Sagi Grimberg, chaitanya.kulkarni, kernel-janitors, james.smart,
	linux-nvme, linux-kernel, Christophe JAILLET, hch

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 <christophe.jaillet@wanadoo.fr>
> > > ---
> > > 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.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()'
  2020-08-21  7:58 [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()' Christophe JAILLET
  2020-08-24 20:00 ` Sagi Grimberg
@ 2020-08-25  7:10 ` Christoph Hellwig
  1 sibling, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2020-08-25  7:10 UTC (permalink / raw)
  To: Christophe JAILLET
  Cc: sagi, chaitanya.kulkarni, kernel-janitors, linux-kernel,
	linux-nvme, james.smart, hch

On Fri, Aug 21, 2020 at 09:58:19AM +0200, Christophe JAILLET 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 <christophe.jaillet@wanadoo.fr>
> ---
> Not tested, only based on what looks logical to me according to
> surrounding code

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-08-25  7:10 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-21  7:58 [PATCH] nvmet-fc: Fix a missed _irqsave version of spin_lock in 'nvmet_fc_fod_op_done()' Christophe JAILLET
2020-08-24 20:00 ` Sagi Grimberg
2020-08-24 21:16   ` Keith Busch
2020-08-25  7:09     ` Christoph Hellwig
2020-08-25  7:10 ` Christoph Hellwig

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).