2010-08-05 19:30:50

by Hank Janssen

Subject: [PATCH 5/5] staging: hv: Gracefully handle SCSI resets

From: Hank Janssen <[email protected]>

If we get a SCSI host bus reset we now gracefully handle it, and we take the
device offline. This before sometimes caused hangs.

Signed-off-by:Hank Janssen <[email protected]>
Signed-off-by:Haiyang Zhang <[email protected]>
Cc: stable <[email protected]>

---
drivers/staging/hv/storvsc.c | 36 +++++++++++++++++++++++++++++++++++-
1 files changed, 35 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/hv/storvsc.c b/drivers/staging/hv/storvsc.c index 6bd2ff1..5f222cf 100644
--- a/drivers/staging/hv/storvsc.c
+++ b/drivers/staging/hv/storvsc.c
@@ -48,7 +48,9 @@ struct storvsc_device {

/* 0 indicates the device is being destroyed */
atomic_t RefCount;
-
+
+ int reset;
+ spinlock_t lock;
atomic_t NumOutstandingRequests;

/*
@@ -93,6 +95,9 @@ static inline struct storvsc_device *AllocStorDevice(struct hv_device *Device)
atomic_cmpxchg(&storDevice->RefCount, 0, 2);

storDevice->Device = Device;
+ storDevice->reset = 0;
+ spin_lock_init(&storDevice->lock);
+
Device->Extension = storDevice;

return storDevice;
@@ -101,6 +106,7 @@ static inline struct storvsc_device *AllocStorDevice(struct hv_device *Device) static inline void FreeStorDevice(struct storvsc_device *Device) {
/* ASSERT(atomic_read(&Device->RefCount) == 0); */
+ /*kfree(Device->lock);*/
kfree(Device);
}

@@ -108,13 +114,24 @@ static inline void FreeStorDevice(struct storvsc_device *Device) static inline struct storvsc_device *GetStorDevice(struct hv_device *Device) {
struct storvsc_device *storDevice;
+ unsigned long flags;

storDevice = (struct storvsc_device *)Device->Extension;
+
+ spin_lock_irqsave(&storDevice->lock, flags);
+
+ if (storDevice->reset == 1) {
+ spin_unlock_irqrestore(&storDevice->lock, flags);
+ return NULL;
+ }
+
if (storDevice && atomic_read(&storDevice->RefCount) > 1)
atomic_inc(&storDevice->RefCount);
else
storDevice = NULL;

+ spin_unlock_irqrestore(&storDevice->lock, flags);
+
return storDevice;
}

@@ -122,13 +139,19 @@ static inline struct storvsc_device *GetStorDevice(struct hv_device *Device) static inline struct storvsc_device *MustGetStorDevice(struct hv_device *Device) {
struct storvsc_device *storDevice;
+ unsigned long flags;

storDevice = (struct storvsc_device *)Device->Extension;
+
+ spin_lock_irqsave(&storDevice->lock, flags);
+
if (storDevice && atomic_read(&storDevice->RefCount))
atomic_inc(&storDevice->RefCount);
else
storDevice = NULL;

+ spin_unlock_irqrestore(&storDevice->lock, flags);
+
return storDevice;
}

@@ -614,6 +637,7 @@ int StorVscOnHostReset(struct hv_device *Device)
struct storvsc_device *storDevice;
struct storvsc_request_extension *request;
struct vstor_packet *vstorPacket;
+ unsigned long flags;
int ret;

DPRINT_INFO(STORVSC, "resetting host adapter..."); @@ -625,6 +649,16 @@ int StorVscOnHostReset(struct hv_device *Device)
return -1;
}

+ spin_lock_irqsave(&storDevice->lock, flags);
+ storDevice->reset = 1;
+ spin_unlock_irqrestore(&storDevice->lock, flags);
+
+ /*
+ * Wait for traffic in transit to complete
+ */
+ while (atomic_read(&storDevice->NumOutstandingRequests))
+ udelay(1000);
+
request = &storDevice->ResetRequest;
vstorPacket = &request->VStorPacket;

--
1.6.0.2

2010-08-31 00:00:07

by Greg KH

Subject: Re: [PATCH 5/5] staging: hv: Gracefully handle SCSI resets

On Thu, Aug 05, 2010 at 07:30:37PM +0000, Hank Janssen wrote:
> From: Hank Janssen <[email protected]>
>
> If we get a SCSI host bus reset we now gracefully handle it, and we take the
> device offline. This before sometimes caused hangs.
>
> Signed-off-by:Hank Janssen <[email protected]>
> Signed-off-by:Haiyang Zhang <[email protected]>
> Cc: stable <[email protected]>
>
> ---
> drivers/staging/hv/storvsc.c | 36 +++++++++++++++++++++++++++++++++++-
> 1 files changed, 35 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/staging/hv/storvsc.c b/drivers/staging/hv/storvsc.c index 6bd2ff1..5f222cf 100644
> --- a/drivers/staging/hv/storvsc.c
> +++ b/drivers/staging/hv/storvsc.c
> @@ -48,7 +48,9 @@ struct storvsc_device {
>
> /* 0 indicates the device is being destroyed */
> atomic_t RefCount;
> -
> +
> + int reset;
> + spinlock_t lock;
> atomic_t NumOutstandingRequests;
>
> /*
> @@ -93,6 +95,9 @@ static inline struct storvsc_device *AllocStorDevice(struct hv_device *Device)
> atomic_cmpxchg(&storDevice->RefCount, 0, 2);
>
> storDevice->Device = Device;
> + storDevice->reset = 0;
> + spin_lock_init(&storDevice->lock);
> +
> Device->Extension = storDevice;
>
> return storDevice;
> @@ -101,6 +106,7 @@ static inline struct storvsc_device *AllocStorDevice(struct hv_device *Device) static inline void FreeStorDevice(struct storvsc_device *Device) {
> /* ASSERT(atomic_read(&Device->RefCount) == 0); */

This patch is corrupted as well, something odd is going on in your email
system :(

care to resend it?

thanks,

greg k-h