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(&aac_mutex);
> + dev->adapter_shutdown = 1;
> + mutex_unlock(&aac_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)
> /* 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
> >> <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_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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