[PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Hank Janssen]

From: Hank Janssen <hjanssen@microsoft.com> 

Fixed bounce offset kmap problem by using correct index

Signed-off-by:Hank Janssen <hjanssen@microsoft.com>
Signed-off-by:Haiyang Zhang <haiyangz@microsoft.com>

---
 drivers/staging/hv/storvsc_drv.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 075b61b..3b9ccb0 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -495,7 +495,7 @@ static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 
 		/* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 
-		if (j == 0)
+		if (bounce_addr == 0)
 			bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 
 		while (srclen) {
@@ -556,7 +556,7 @@ static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 		destlen = orig_sgl[i].length;
 		/* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 
-		if (j == 0)
+		if (bounce_addr == 0)
 			bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 
 		while (destlen) {
--
1.6.0.2

Re: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Greg KH]

On Tue, Aug 03, 2010 at 05:31:51PM +0000, Hank Janssen wrote:
> From: Hank Janssen <hjanssen@microsoft.com> 
> 
> Fixed bounce offset kmap problem by using correct index

Is this a bugfix that needs to go to previous kernel releases?  If so,
which ones?  What is the symptom of the problem here?

thanks,

greg k-h

RE: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Hank Janssen]

And then Greg spoke:
>>On Tue, Aug 03, 2010 at 05:31:51PM +0000, Hank Janssen wrote:
>> From: Hank Janssen <hjanssen@microsoft.com>
>> 
> >Fixed bounce offset kmap problem by using correct index
>
>Is this a bugfix that needs to go to previous kernel releases?  If so, which ones?  What is the symptom of the problem here?

Yes, this should be backported to all stable kernel releases that have the Hyper-V drivers In them.  

The symptom of the problem is that in some NAS appliances this problem represents
Itself by a unresponsive VM under a load with many clients writing small files.

I actually goofed up in my previous code and used an incorrect index number
For this part of the code. It should have shown up in more situations than what
I have seen oddly enough.

Hank.

Re: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Greg KH]

On Wed, Aug 04, 2010 at 04:35:06AM +0000, Hank Janssen wrote:
> 
> And then Greg spoke:
> >>On Tue, Aug 03, 2010 at 05:31:51PM +0000, Hank Janssen wrote:
> >> From: Hank Janssen <hjanssen@microsoft.com>
> >> 
> > >Fixed bounce offset kmap problem by using correct index
> >
> >Is this a bugfix that needs to go to previous kernel releases?  If so, which ones?  What is the symptom of the problem here?
> 
> Yes, this should be backported to all stable kernel releases that have the Hyper-V drivers In them.  
> 
> The symptom of the problem is that in some NAS appliances this problem represents
> Itself by a unresponsive VM under a load with many clients writing small files.
> 
> I actually goofed up in my previous code and used an incorrect index number
> For this part of the code. It should have shown up in more situations than what
> I have seen oddly enough.

Please provide this type of information in the changelog section.

If you want something backported to older stable kernels, add a:
	Cc: stable <stable@kernel.org>
to the signed-off-by area of the patch and it will be automatically sent
to the stable alias when it gets included in Linus's tree so I know to
pick it up then.

Care to resend all of these patches based on these comments?

thanks,

greg k-h

RE: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Hank Janssen]

>And then Greg spoke:
>> And then Greg spoke:
> >>>On Tue, Aug 03, 2010 at 05:31:51PM +0000, Hank Janssen wrote:
> >>> From: Hank Janssen <hjanssen@microsoft.com>
> >>> 
> >> >Fixed bounce offset kmap problem by using correct index
> >>

SNIP

> > I actually goofed up in my previous code and used an incorrect index 
> > number For this part of the code. It should have shown up in more 
> > situations than what I have seen oddly enough.
>
>Please provide this type of information in the changelog section.
>
>If you want something backported to older stable kernels, add a:
>	Cc: stable <stable@kernel.org>

I will re-submit all 5 patches and CC the stable mailing list on it as well.

Thanks!

Hank.

Re: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Greg KH]

On Wed, Aug 04, 2010 at 05:17:21PM +0000, Hank Janssen wrote:
> 
> >And then Greg spoke:
> >> And then Greg spoke:
> > >>>On Tue, Aug 03, 2010 at 05:31:51PM +0000, Hank Janssen wrote:
> > >>> From: Hank Janssen <hjanssen@microsoft.com>
> > >>> 
> > >> >Fixed bounce offset kmap problem by using correct index
> > >>
> 
> SNIP
> 
> > > I actually goofed up in my previous code and used an incorrect index 
> > > number For this part of the code. It should have shown up in more 
> > > situations than what I have seen oddly enough.
> >
> >Please provide this type of information in the changelog section.
> >
> >If you want something backported to older stable kernels, add a:
> >	Cc: stable <stable@kernel.org>
> 
> I will re-submit all 5 patches and CC the stable mailing list on it as well.

5?  I see 6 of them here :)

thanks,

greg k-h

Re: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Hank Janssen]

On Aug 4, 2010, at 11:26, Greg KH <gregkh@suse.de> wrote:

> On Wed, Aug 04, 2010 at 05:17:21PM +0000, Hank Janssen wrote:
>>> 
>> 
>> I will re-submit all 5 patches and CC the stable mailing list on it as well.
> 
> 5?  I see 6 of them here :)
> 
> thanks,
> 
> greg k-h
> 

True but anise you rejected the todo patch there will only be 5.
Unless you are willing to take the todo patch. :)

Hank. 

Re: [PATCH 1/6] staging: hv: Fixed bounce kmap problem by using correct index

[Greg KH]

On Wed, Aug 04, 2010 at 06:50:24PM +0000, Hank Janssen wrote:
> On Aug 4, 2010, at 11:26, Greg KH <gregkh@suse.de> wrote:
> > On Wed, Aug 04, 2010 at 05:17:21PM +0000, Hank Janssen wrote:
> >>> 
> >> 
> >> I will re-submit all 5 patches and CC the stable mailing list on it as well.
> > 
> > 5?  I see 6 of them here :)
> > 
> > thanks,
> > 
> > greg k-h
> > 
> 
> True but anise you rejected the todo patch there will only be 5.
> Unless you are willing to take the todo patch. :)

Doh, you are right, nevermind :)

thanks,

greg k-h