On 20.1.2016 21:32, Raghava Aditya Renukunta wrote:
>
>> -----Original Message-----
>> From: Tomas Henzl [mailto:[email protected]]
>> Sent: Tuesday, January 19, 2016 8:14 AM
>> To: Raghava Aditya Renukunta; [email protected];
>> [email protected]; [email protected]
>> Cc: Mahesh Rajashekhara; Murthy Bhat; Gana Sridaran; aacraid@pmc-
>> sierra.com; Scott Benesh; [email protected]; [email protected];
>> 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 <[email protected]>
>>>
>>> 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(&aac_mutex);
+ dev->adapter_shutdown = 1;
+ mutex_unlock(&aac_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(&aac_mutex);
ret = aac_do_ioctl(file->private_data, cmd, (void __user *)arg);
mutex_unlock(&aac_mutex);
>
> I am more inclined to go with option 2.
>
> Regards,
> Raghava Aditya
>
>>> Signed-off-by: Raghava Aditya Renukunta
>> <[email protected]>
>>> ---
>>> 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_t adapter_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(&dev->adapter_shutdown, 1);
>>>
>>> + cmd = (struct aac_close *) fib_data(fibctx);
>>> cmd->command = cpu_to_le32(VM_CloseAll);
>>> cmd->cid = cpu_to_le32(0xfffffffe);
>>>
>>> @@ -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(&dev->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/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
>>> index 6944560..27b3fcd 100644
>>> --- a/drivers/scsi/aacraid/linit.c
>>> +++ b/drivers/scsi/aacraid/linit.c
>>> @@ -706,7 +706,7 @@ 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) || atomic_read(&aac-
>>> adapter_shutdown))
>>> return -EPERM;
>>> mutex_lock(&aac_mutex);
>>> ret = aac_do_ioctl(file->private_data, cmd, (void __user *)arg);
>>> @@ -1078,6 +1078,8 @@ static void __aac_shutdown(struct aac_dev * aac)
>>> int i;
>>> int cpu;
>>>
>>> + aac_send_shutdown(aac);
>>> +
>>> if (aac->aif_thread) {
>>> int i;
>>> /* Clear out events first */
>>> @@ -1089,7 +1091,7 @@ static void __aac_shutdown(struct aac_dev * aac)
>>> }
>>> kthread_stop(aac->thread);
>>> }
>>> - aac_send_shutdown(aac);
>>> +
>>> aac_adapter_disable_int(aac);
>>> cpu = cpumask_first(cpu_online_mask);
>>> if (aac->pdev->device == PMC_DEVICE_S6 ||
>>> @@ -1474,7 +1476,7 @@ static int aac_resume(struct pci_dev *pdev)
>>> * reset this flag to unblock ioctl() as it was set at
>>> * aac_send_shutdown() to block ioctls from upperlayer
>>> */
>>> - aac->adapter_shutdown = 0;
>>> + atomic_set(&aac->adapter_shutdown, 0);
>>> scsi_unblock_requests(shost);
>>>
>>> return 0;
>>> @@ -1553,9 +1555,8 @@ static pci_ers_result_t
>> aac_pci_error_detected(struct pci_dev *pdev,
>>> case pci_channel_io_normal:
>>> return PCI_ERS_RESULT_CAN_RECOVER;
>>> case pci_channel_io_frozen:
>>> -
>>> aac->handle_pci_error = 1;
>>> - aac->adapter_shutdown = 1;
>>> + atomic_set(&aac->adapter_shutdown, 1);
>>>
>>> scsi_block_requests(aac->scsi_host_ptr);
>>> aac_flush_ios(aac);
>>> @@ -1567,7 +1568,7 @@ static pci_ers_result_t
>> aac_pci_error_detected(struct pci_dev *pdev,
>>> return PCI_ERS_RESULT_NEED_RESET;
>>> case pci_channel_io_perm_failure:
>>> aac->handle_pci_error = 1;
>>> - aac->adapter_shutdown = 1;
>>> + atomic_set(&aac->adapter_shutdown, 1);
>>>
>>> aac_flush_ios(aac);
>>> return PCI_ERS_RESULT_DISCONNECT;
>>> @@ -1636,7 +1637,7 @@ static void aac_pci_resume(struct pci_dev *pdev)
>>> * reset this flag to unblock ioctl() as it was set
>>> * at aac_send_shutdown() to block ioctls from upperlayer
>>> */
>>> - aac->adapter_shutdown = 0;
>>> + atomic_set(&aac->adapter_shutdown, 0);
>>> aac->handle_pci_error = 0;
>>>
>>> shost_for_each_device(sdev, shost)
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