[PATCH 1/5] staging: hv: Fixed bounce kmap problem by using correct index

[Hank Janssen]

From: Hank Janssen <hjanssen at microsoft.com> 

Fixed bounce offset kmap problem by using correct index.
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.

Signed-off-by:Hank Janssen <hjanssen at microsoft.com>
Signed-off-by:Haiyang Zhang <haiyangz at microsoft.com>
Cc: stable <stable at kernel.org>
---
 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