RE: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET

2016-01-27 Thread Raghava Aditya Renukunta 
Hello Martin,

> -Original Message-
> From: Martin K. Petersen [mailto:martin.peter...@oracle.com]
> Sent: Tuesday, January 26, 2016 6:31 PM
> To: Raghava Aditya Renukunta
> Cc: Tomas Henzl; james.bottom...@hansenpartnership.com;
> martin.peter...@oracle.com; linux-scsi@vger.kernel.org; Mahesh
> Rajashekhara; Murthy Bhat; Gana Sridaran; aacr...@pmc-sierra.com; Scott
> Benesh; jthumsh...@suse.de; shane.seym...@hpe.com; zzzDavid Carroll
> Subject: Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET
> 
> >>>>> "Tomas" == Tomas Henzl <the...@redhat.com> writes:
> 
> >> 2.Since commands are sync , place a check in aac_fib_send to block
> >> commands once adapter_shutdown is set(only shutdown command will
> be
> >> sent thru)
> 
> Tomas> This option looks better but I guess you still can find a tiny
> Tomas> race window.  What do you think about a mutual exclusive access
> Tomas> using a mutex, do you think this could work?
> 
> [...]
> 
> Raghava?

I have replied that I will create a new set patches with this change shortly. 
Please expect it by tomorrow at the latest.

Regards,
Raghava Aditya

> 
> --
> Martin K. PetersenOracle Linux Engineering
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Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET

2016-01-26 Thread Martin K. Petersen 
> "Tomas" == Tomas Henzl  writes:

>> 2.Since commands are sync , place a check in aac_fib_send to block
>> commands once adapter_shutdown is set(only shutdown command will be
>> sent thru)

Tomas> This option looks better but I guess you still can find a tiny
Tomas> race window.  What do you think about a mutual exclusive access
Tomas> using a mutex, do you think this could work?

[...]

Raghava?

-- 
Martin K. Petersen  Oracle Linux Engineering
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Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET

2016-01-22 Thread Tomas Henzl 
On 20.1.2016 21:32, Raghava Aditya Renukunta wrote:
>
>> -Original Message-
>> From: Tomas Henzl [mailto:the...@redhat.com]
>> Sent: Tuesday, January 19, 2016 8:14 AM
>> To: Raghava Aditya Renukunta; james.bottom...@hansenpartnership.com;
>> martin.peter...@oracle.com; linux-scsi@vger.kernel.org
>> Cc: Mahesh Rajashekhara; Murthy Bhat; Gana Sridaran; aacraid@pmc-
>> sierra.com; Scott Benesh; jthumsh...@suse.de; shane.seym...@hpe.com;
>> David Carroll
>> Subject: Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET
>>
>> On 15.1.2016 08:16, Raghava Aditya Renukunta wrote:
>>> From: Raghava Aditya Renukunta <raghavaaditya.renuku...@pmcs.com>
>>>
>>> while driver removal is in progress or PCI shutdown is invoked, driver
>>> kills AIF aacraid thread, but IOCTL requests from the management tools
>>> re-start AIF thread leading to IOP_RESET.
>>>
>>> Fixed by setting adapter_shutdown flag when PCI shutdown is invoked.
>>>
>>> Changes in V2:
>>> Set adapter_shutdown flag before shutdown command is sent to \
>>> controller
>>>
>>> Changes in V3:
>>> Call aac_send_shut_shutdown first thing in __aac_shutdown
>>> Convert adapter_shutdown to atomic_t variable to prevent \
>>> SMP coherency issues(race conditions)
>> Hi,
>> I don't think that an atomic variable can change it, imagine that
>> thread just passed your test in aac_cfg_ioctl and another thread
>> enter a bit later the adapter_shutdown so both - an I/O and your shutdown
>> code
>> will run in parallel.
>> Also you need to fix your compat_ioctl path too.
>>
>> --tm
> Hello Tomas,
> Yes that would not solve this problem.
> I can think of 2 solutions
>
> 1.Place a delay after setting adapter_shutdown and before sending the actual
> shutdown command in aac_send_shutdown. This way any impending commands will 
> be 
> processed before the adapter  actually receives the shutdown command. Since 
> management 
> commands are sync only , shutdown command will be sent last. This solution 
> uses an
> estimation of the delay
>
> 2.Since  commands are sync , place a check in aac_fib_send to block 
>  commands once adapter_shutdown is set(only shutdown command will be sent 
> thru)

This option looks better but I guess you still can find a tiny race window.
What do you think about a mutual exclusive access using a mutex, do you think 
this could work?

diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
index 54195a117f..b9505c58db 100644
--- a/drivers/scsi/aacraid/commctrl.c
+++ b/drivers/scsi/aacraid/commctrl.c
@@ -858,6 +858,8 @@ int aac_do_ioctl(struct aac_dev * dev, int cmd, void __user 
*arg)
/*
 *  HBA gets first crack
 */
+   if (dev->adapter_shutdown)
+   return -EACCES;
 
status = aac_dev_ioctl(dev, cmd, arg);
if (status != -ENOTTY)
diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index 0e954e37f0..02535c07a4 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -212,6 +212,10 @@ int aac_send_shutdown(struct aac_dev * dev)
return -ENOMEM;
aac_fib_init(fibctx);
 
+   mutex_lock(_mutex);
+   dev->adapter_shutdown = 1;
+   mutex_unlock(_mutex);
+
cmd = (struct aac_close *) fib_data(fibctx);
 
cmd->command = cpu_to_le32(VM_CloseAll);
@@ -229,7 +233,6 @@ int aac_send_shutdown(struct aac_dev * dev)
/* FIB should be freed only after getting the response from the F/W */
if (status != -ERESTARTSYS)
aac_fib_free(fibctx);
-   dev->adapter_shutdown = 1;
if ((dev->pdev->device == PMC_DEVICE_S7 ||
 dev->pdev->device == PMC_DEVICE_S8 ||
 dev->pdev->device == PMC_DEVICE_S9) &&
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index 6944560e22..a87880ab32 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -706,8 +706,9 @@ static long aac_cfg_ioctl(struct file *file,
int ret;
struct aac_dev *aac;
aac = (struct aac_dev *)file->private_data;
-   if (!capable(CAP_SYS_RAWIO) || aac->adapter_shutdown)
+   if (!capable(CAP_SYS_RAWIO))
return -EPERM;
+
mutex_lock(_mutex);
ret = aac_do_ioctl(file->private_data, cmd, (void __user *)arg);
mutex_unlock(_mutex);

>
> I am more inclined to go with option 2.
>
> Regards,
> Raghava Aditya
>
>>> Signed-off-by: Raghava Aditya Renukunta
>> <raghavaaditya.renuku...@pmcs.com>
>>> ---
>>>  drivers/scsi/aacraid/aacraid.h

RE: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET

2016-01-22 Thread Raghava Aditya Renukunta 
Hello Tomas,

> -Original Message-
> From: Tomas Henzl [mailto:the...@redhat.com]
> Sent: Friday, January 22, 2016 5:15 AM
> To: Raghava Aditya Renukunta; james.bottom...@hansenpartnership.com;
> martin.peter...@oracle.com; linux-scsi@vger.kernel.org
> Cc: Mahesh Rajashekhara; Murthy Bhat; Gana Sridaran; aacraid@pmc-
> sierra.com; Scott Benesh; jthumsh...@suse.de; shane.seym...@hpe.com;
> zzzDavid Carroll
> Subject: Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET
> 
> On 20.1.2016 21:32, Raghava Aditya Renukunta wrote:
> >
> >> -Original Message-
> >> From: Tomas Henzl [mailto:the...@redhat.com]
> >> Sent: Tuesday, January 19, 2016 8:14 AM
> >> To: Raghava Aditya Renukunta;
> james.bottom...@hansenpartnership.com;
> >> martin.peter...@oracle.com; linux-scsi@vger.kernel.org
> >> Cc: Mahesh Rajashekhara; Murthy Bhat; Gana Sridaran; aacraid@pmc-
> >> sierra.com; Scott Benesh; jthumsh...@suse.de;
> shane.seym...@hpe.com;
> >> David Carroll
> >> Subject: Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET
> >>
> >> On 15.1.2016 08:16, Raghava Aditya Renukunta wrote:
> >>> From: Raghava Aditya Renukunta
> <raghavaaditya.renuku...@pmcs.com>
> >>>
> >>> while driver removal is in progress or PCI shutdown is invoked, driver
> >>> kills AIF aacraid thread, but IOCTL requests from the management tools
> >>> re-start AIF thread leading to IOP_RESET.
> >>>
> >>> Fixed by setting adapter_shutdown flag when PCI shutdown is invoked.
> >>>
> >>> Changes in V2:
> >>> Set adapter_shutdown flag before shutdown command is sent to \
> >>> controller
> >>>
> >>> Changes in V3:
> >>> Call aac_send_shut_shutdown first thing in __aac_shutdown
> >>> Convert adapter_shutdown to atomic_t variable to prevent \
> >>> SMP coherency issues(race conditions)
> >> Hi,
> >> I don't think that an atomic variable can change it, imagine that
> >> thread just passed your test in aac_cfg_ioctl and another thread
> >> enter a bit later the adapter_shutdown so both - an I/O and your
> shutdown
> >> code
> >> will run in parallel.
> >> Also you need to fix your compat_ioctl path too.
> >>
> >> --tm
> > Hello Tomas,
> > Yes that would not solve this problem.
> > I can think of 2 solutions
> >
> > 1.Place a delay after setting adapter_shutdown and before sending the
> actual
> > shutdown command in aac_send_shutdown. This way any impending
> commands will be
> > processed before the adapter  actually receives the shutdown command.
> Since management
> > commands are sync only , shutdown command will be sent last. This
> solution uses an
> > estimation of the delay
> >
> > 2.Since  commands are sync , place a check in aac_fib_send to block
> >  commands once adapter_shutdown is set(only shutdown command will
> be sent thru)
> 
> This option looks better but I guess you still can find a tiny race window.
> What do you think about a mutual exclusive access using a mutex, do you
> think this could work?
> diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
> index 54195a117f..b9505c58db 100644
> --- a/drivers/scsi/aacraid/commctrl.c
> +++ b/drivers/scsi/aacraid/commctrl.c
> @@ -858,6 +858,8 @@ int aac_do_ioctl(struct aac_dev * dev, int cmd, void
> __user *arg)
>   /*
>*  HBA gets first crack
>*/
> + if (dev->adapter_shutdown)
> + return -EACCES;
> 
>   status = aac_dev_ioctl(dev, cmd, arg);
>   if (status != -ENOTTY)
> diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
> index 0e954e37f0..02535c07a4 100644
> --- a/drivers/scsi/aacraid/comminit.c
> +++ b/drivers/scsi/aacraid/comminit.c
> @@ -212,6 +212,10 @@ int aac_send_shutdown(struct aac_dev * dev)
>   return -ENOMEM;
>   aac_fib_init(fibctx);
> 
> + mutex_lock(_mutex);
> + dev->adapter_shutdown = 1;
> + mutex_unlock(_mutex);
> +
 
The  intention here is to have mutually exclusive access to adapter_shutdown, or
aac_do_Ioctl  which has a check for adapter_shutdown so  either one can be
 command is sent at one time if I am not mistaken?.
 Yes this solution will work. I will make the necessary changes. 
Thank you.

Regards,
Raghava Aditya

 
>   cmd = (struct aac_close *) fib_data(fibctx);
> 
>   cmd->command = cpu_to_le32(VM_CloseAll);
> @@ -229,7 +233,6 @@ int aac_send_shutdown(struct aac_dev * dev)
>   /* F

RE: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET

2016-01-20 Thread Raghava Aditya Renukunta 


> -Original Message-
> From: Tomas Henzl [mailto:the...@redhat.com]
> Sent: Tuesday, January 19, 2016 8:14 AM
> To: Raghava Aditya Renukunta; james.bottom...@hansenpartnership.com;
> martin.peter...@oracle.com; linux-scsi@vger.kernel.org
> Cc: Mahesh Rajashekhara; Murthy Bhat; Gana Sridaran; aacraid@pmc-
> sierra.com; Scott Benesh; jthumsh...@suse.de; shane.seym...@hpe.com;
> David Carroll
> Subject: Re: [PATCH V3 7/9] aacraid: Fix AIF triggered IOP_RESET
> 
> On 15.1.2016 08:16, Raghava Aditya Renukunta wrote:
> > From: Raghava Aditya Renukunta <raghavaaditya.renuku...@pmcs.com>
> >
> > while driver removal is in progress or PCI shutdown is invoked, driver
> > kills AIF aacraid thread, but IOCTL requests from the management tools
> > re-start AIF thread leading to IOP_RESET.
> >
> > Fixed by setting adapter_shutdown flag when PCI shutdown is invoked.
> >
> > Changes in V2:
> > Set adapter_shutdown flag before shutdown command is sent to \
> > controller
> >
> > Changes in V3:
> > Call aac_send_shut_shutdown first thing in __aac_shutdown
> > Convert adapter_shutdown to atomic_t variable to prevent \
> > SMP coherency issues(race conditions)
> 
> Hi,
> I don't think that an atomic variable can change it, imagine that
> thread just passed your test in aac_cfg_ioctl and another thread
> enter a bit later the adapter_shutdown so both - an I/O and your shutdown
> code
> will run in parallel.
> Also you need to fix your compat_ioctl path too.
> 
> --tm

Hello Tomas,
Yes that would not solve this problem.
I can think of 2 solutions

1.Place a delay after setting adapter_shutdown and before sending the actual
shutdown command in aac_send_shutdown. This way any impending commands will be 
processed before the adapter  actually receives the shutdown command. Since 
management 
commands are sync only , shutdown command will be sent last. This solution uses 
an
estimation of the delay

2.Since  commands are sync , place a check in aac_fib_send to block 
 commands once adapter_shutdown is set(only shutdown command will be sent thru)

I am more inclined to go with option 2.

Regards,
Raghava Aditya

> >
> > Signed-off-by: Raghava Aditya Renukunta
> <raghavaaditya.renuku...@pmcs.com>
> > ---
> >  drivers/scsi/aacraid/aacraid.h  |  2 +-
> >  drivers/scsi/aacraid/comminit.c |  6 +++---
> >  drivers/scsi/aacraid/linit.c| 15 ---
> >  3 files changed, 12 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
> > index 2916288..3473668 100644
> > --- a/drivers/scsi/aacraid/aacraid.h
> > +++ b/drivers/scsi/aacraid/aacraid.h
> > @@ -1234,7 +1234,7 @@ struct aac_dev
> > int msi_enabled;/* MSI/MSI-X enabled */
> > struct msix_entry   msixentry[AAC_MAX_MSIX];
> > struct aac_msix_ctx aac_msix[AAC_MAX_MSIX]; /* context */
> > -   u8  adapter_shutdown;
> > +   atomic_tadapter_shutdown;
> > u32 handle_pci_error;
> >  };
> >
> > diff --git a/drivers/scsi/aacraid/comminit.c
> b/drivers/scsi/aacraid/comminit.c
> > index 0e954e3..d361673 100644
> > --- a/drivers/scsi/aacraid/comminit.c
> > +++ b/drivers/scsi/aacraid/comminit.c
> > @@ -212,8 +212,9 @@ int aac_send_shutdown(struct aac_dev * dev)
> > return -ENOMEM;
> > aac_fib_init(fibctx);
> >
> > -   cmd = (struct aac_close *) fib_data(fibctx);
> > +   atomic_set(>adapter_shutdown, 1);
> >
> > +   cmd = (struct aac_close *) fib_data(fibctx);
> > cmd->command = cpu_to_le32(VM_CloseAll);
> > cmd->cid = cpu_to_le32(0xfffe);
> >
> > @@ -229,7 +230,6 @@ int aac_send_shutdown(struct aac_dev * dev)
> > /* FIB should be freed only after getting the response from the F/W
> */
> > if (status != -ERESTARTSYS)
> > aac_fib_free(fibctx);
> > -   dev->adapter_shutdown = 1;
> > if ((dev->pdev->device == PMC_DEVICE_S7 ||
> >  dev->pdev->device == PMC_DEVICE_S8 ||
> >  dev->pdev->device == PMC_DEVICE_S9) &&
> > @@ -468,7 +468,7 @@ struct aac_dev *aac_init_adapter(struct aac_dev
> *dev)
> > }
> > dev->max_msix = 0;
> > dev->msi_enabled = 0;
> > -   dev->adapter_shutdown = 0;
> > +   atomic_set(>adapter_shutdown, 0);
> > if ((!aac_adapter_sync_cmd(dev,
> GET_COMM_PREFERRED_SETTINGS,
> >   0, 0, 0, 0, 0, 0,
> >   status+0, status+1, status+2, status+3, status+4))
> > diff --git a/