2010-08-05 19:30:24

by Hank Janssen

Subject: [PATCH 2/5] staging: hv: Fixed lockup problem with bounce_buffer scatter list

From: Hank Janssen <[email protected]>

Fixed lockup problem with bounce_buffer scatter list which caused
crashes in heavy loads. Under heavy loads with many clients we this
problem appear, it causes a kernel Panic.

Signed-off-by:Hank Janssen <[email protected]>
Signed-off-by:Haiyang Zhang <[email protected]>
Cc: stable <[email protected]>
---
drivers/staging/hv/storvsc_drv.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 3b9ccb0..169d701 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -615,6 +615,7 @@ static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
unsigned int request_size = 0;
int i;
struct scatterlist *sgl;
+ unsigned int sg_count = 0;

DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
"queue depth %d tagged %d", scmnd, scmnd->sc_data_direction, @@ -697,6 +698,7 @@ static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
request->DataBuffer.Length = scsi_bufflen(scmnd);
if (scsi_sg_count(scmnd)) {
sgl = (struct scatterlist *)scsi_sglist(scmnd);
+ sg_count = scsi_sg_count(scmnd);

/* check if we need to bounce the sgl */
if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) { @@ -731,15 +733,16 @@ static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
scsi_sg_count(scmnd));

sgl = cmd_request->bounce_sgl;
+ sg_count = cmd_request->bounce_sgl_count;
}

request->DataBuffer.Offset = sgl[0].offset;

- for (i = 0; i < scsi_sg_count(scmnd); i++) {
+ for (i = 0; i < sg_count; i++) {
DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d\n",
i, sgl[i].length, sgl[i].offset);
- request->DataBuffer.PfnArray[i] =
- page_to_pfn(sg_page((&sgl[i])));
+ request->DataBuffer.PfnArray[i] =
+ page_to_pfn(sg_page((&sgl[i])));
}
} else if (scsi_sglist(scmnd)) {
/* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
--
1.6.0.2

2010-08-31 00:00:06

by Greg KH

Subject: Re: [PATCH 2/5] staging: hv: Fixed lockup problem with bounce_buffer scatter list

On Thu, Aug 05, 2010 at 07:29:53PM +0000, Hank Janssen wrote:
> From: Hank Janssen <[email protected]>
>
> Fixed lockup problem with bounce_buffer scatter list which caused
> crashes in heavy loads. Under heavy loads with many clients we this
> problem appear, it causes a kernel Panic.
>
> Signed-off-by:Hank Janssen <[email protected]>
> Signed-off-by:Haiyang Zhang <[email protected]>
> Cc: stable <[email protected]>
> ---
> drivers/staging/hv/storvsc_drv.c | 9 ++++++---
> 1 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
> index 3b9ccb0..169d701 100644
> --- a/drivers/staging/hv/storvsc_drv.c
> +++ b/drivers/staging/hv/storvsc_drv.c
> @@ -615,6 +615,7 @@ static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
> unsigned int request_size = 0;
> int i;
> struct scatterlist *sgl;
> + unsigned int sg_count = 0;
>
> DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
> "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction, @@ -697,6 +698,7 @@ static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
> request->DataBuffer.Length = scsi_bufflen(scmnd);


This patch is corrupted. It applies, but doesn't do what you want it to
do :(

Care to resend?

thanks,

greg k-h