Staging: hv: storvsc: Fix a bug in copy_from_bounce_buffer()
Fix a bug in copy_from_bounce_buffer().
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
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 8dafe52..c22de06 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -880,7 +880,8 @@
/* Assume the original sgl has enough room */
static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
struct scatterlist *bounce_sgl,
- unsigned int orig_sgl_count)
+ unsigned int orig_sgl_count,
+ unsigned int bounce_sgl_count)
{
int i;
int j = 0;
@@ -921,6 +922,24 @@
kunmap_atomic((void *)bounce_addr, KM_IRQ0);
j++;
+ /*
+ * It is possible that the number of elements
+ * in the bounce buffer may not be equal to
+ * the number of elements in the original
+ * scatter list. Handle this correctly.
+ */
+
+ if (j == bounce_sgl_count) {
+ /*
+ * We are done; cleanup and return.
+ */
+ kunmap_atomic((void *)(dest_addr -
+ orig_sgl[i].offset),
+ KM_IRQ0);
+ local_irq_restore(flags);
+ return total_copied;
+ }
+
/* if we need to use another bounce buffer */
if (destlen || i != orig_sgl_count - 1)
bounce_addr =
@@ -1126,7 +1145,8 @@
if (vm_srb->data_in == READ_TYPE)
copy_from_bounce_buffer(scsi_sglist(scmnd),
cmd_request->bounce_sgl,
- scsi_sg_count(scmnd));
+ scsi_sg_count(scmnd),
+ cmd_request->bounce_sgl_count);
destroy_bounce_buffer(cmd_request->bounce_sgl,
cmd_request->bounce_sgl_count);
}