diff mbox

ligtnvm: if LUNs are already allocated fix return

Message ID 20170627083950.11312-2-matias@cnexlabs.com (mailing list archive)
State New, archived
Headers show

Commit Message

Matias Bjørling June 27, 2017, 8:39 a.m. UTC
From: Rakesh Pandit <rakesh@tuxera.com>

While creating new device with NVM_DEV_CREATE if LUNs are already
allocated ioctl would return -ENOMEM which is wrong.  This patch
propagates -EBUSY from nvm_reserve_luns which is correct response.

Fixes: ade69e243 ("lightnvm: merge gennvm with core")
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
---
 drivers/lightnvm/core.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Comments

Frans Klaver June 27, 2017, 9:06 a.m. UTC | #1
On Tue, Jun 27, 2017 at 10:39 AM, Matias Bjørling <m@bjorling.me> wrote:
> From: Rakesh Pandit <rakesh@tuxera.com>
>
> While creating new device with NVM_DEV_CREATE if LUNs are already
> allocated ioctl would return -ENOMEM which is wrong.  This patch
> propagates -EBUSY from nvm_reserve_luns which is correct response.
>
> Fixes: ade69e243 ("lightnvm: merge gennvm with core")
> Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
> Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
> ---
>  drivers/lightnvm/core.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index b8f82f5..9ff348f 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -235,7 +235,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
>         struct nvm_target *t;
>         struct nvm_tgt_dev *tgt_dev;
>         void *targetdata;
> -       int ret;
> +       int ret = 0;

Is there any way that you can reach a 'return ret' without having ret
set by some other assignment?


>         tt = nvm_find_target_type(create->tgttype, 1);
>         if (!tt) {
> @@ -252,8 +252,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
>         }
>         mutex_unlock(&dev->mlock);
>
> -       if (nvm_reserve_luns(dev, s->lun_begin, s->lun_end))
> -               return -ENOMEM;
> +       ret = nvm_reserve_luns(dev, s->lun_begin, s->lun_end);
> +       if (ret)
> +               goto err;

Why don't you return err straight away here?


>         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
>         if (!t) {
> @@ -314,8 +315,8 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
>         mutex_lock(&dev->mlock);
>         list_add_tail(&t->list, &dev->targets);
>         mutex_unlock(&dev->mlock);
> -
> -       return 0;
> +err:
> +       return ret;

This should not be necessary. In any case, the de-init order should
always be the reverse of the init order, so we don't end up confused.

Frans
Rakesh Pandit June 27, 2017, 9:58 a.m. UTC | #2
Hi Frans,

On Tue, Jun 27, 2017 at 11:06:44AM +0200, Frans Klaver wrote:
> On Tue, Jun 27, 2017 at 10:39 AM, Matias Bjørling wrote:
> > From: Rakesh Pandit <rakesh@tuxera.com>
> >
> > While creating new device with NVM_DEV_CREATE if LUNs are already
> > allocated ioctl would return -ENOMEM which is wrong.  This patch
> > propagates -EBUSY from nvm_reserve_luns which is correct response.
> >
> > Fixes: ade69e243 ("lightnvm: merge gennvm with core")
> > Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
> > Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
> > ---
> >  drivers/lightnvm/core.c | 11 ++++++-----
> >  1 file changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> > index b8f82f5..9ff348f 100644
> > --- a/drivers/lightnvm/core.c
> > +++ b/drivers/lightnvm/core.c
> > @@ -235,7 +235,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
> >         struct nvm_target *t;
> >         struct nvm_tgt_dev *tgt_dev;
> >         void *targetdata;
> > -       int ret;
> > +       int ret = 0;
> 
> Is there any way that you can reach a 'return ret' without having ret
> set by some other assignment?
> 
>

No.

I should have been more careful.

> >         tt = nvm_find_target_type(create->tgttype, 1);
> >         if (!tt) {
> > @@ -252,8 +252,9 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
> >         }
> >         mutex_unlock(&dev->mlock);
> >
> > -       if (nvm_reserve_luns(dev, s->lun_begin, s->lun_end))
> > -               return -ENOMEM;
> > +       ret = nvm_reserve_luns(dev, s->lun_begin, s->lun_end);
> > +       if (ret)
> > +               goto err;
> 
> Why don't you return err straight away here?

Intent was to future-proofing if num_reserve_luns would return
anything other than -EBUSY and 0 but yes returning -EBUSY directly
would be fine.

> 
> 
> >         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
> >         if (!t) {
> > @@ -314,8 +315,8 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
> >         mutex_lock(&dev->mlock);
> >         list_add_tail(&t->list, &dev->targets);
> >         mutex_unlock(&dev->mlock);
> > -
> > -       return 0;
> > +err:
> > +       return ret;
> 
> This should not be necessary. In any case, the de-init order should
> always be the reverse of the init order, so we don't end up confused.

Only if we directly return -EBUSY.  Good point about getting confused
I would resend quickly by directly returning error.  That would not
confuse folks.

I would send an alternate patch which returns -EBUSY directly and do
same thing.

Thanks,

> 
> Frans
diff mbox

Patch

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index b8f82f5..9ff348f 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -235,7 +235,7 @@  static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
 	struct nvm_target *t;
 	struct nvm_tgt_dev *tgt_dev;
 	void *targetdata;
-	int ret;
+	int ret = 0;
 
 	tt = nvm_find_target_type(create->tgttype, 1);
 	if (!tt) {
@@ -252,8 +252,9 @@  static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
 	}
 	mutex_unlock(&dev->mlock);
 
-	if (nvm_reserve_luns(dev, s->lun_begin, s->lun_end))
-		return -ENOMEM;
+	ret = nvm_reserve_luns(dev, s->lun_begin, s->lun_end);
+	if (ret)
+		goto err;
 
 	t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 	if (!t) {
@@ -314,8 +315,8 @@  static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
 	mutex_lock(&dev->mlock);
 	list_add_tail(&t->list, &dev->targets);
 	mutex_unlock(&dev->mlock);
-
-	return 0;
+err:
+	return ret;
 err_sysfs:
 	if (tt->exit)
 		tt->exit(targetdata);