staging: hv: Fixed bounce kmap problem by using correct index

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@microsoft.com>
Signed-off-by:Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 075b61bd492f19918c1ee3027994362b2b6aa900..3b9ccb06200811a37da503fd6a7b88a2806e1b5d 100644 (file)
--- 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) {