staging: hv: Fixed lockup problem with bounce_buffer scatter list

commit 77c5ceaff31645ea049c6706b99e699eae81fb88 upstream.

Fixed lockup problem with bounce_buffer scatter list which caused
crashes in heavy loads. And minor code indentation cleanup in effected
area.

Removed whitespace and noted minor indentation changes in description as
pointed out by Joe Perches. (Thanks for reviewing Joe)

Signed-off-by: Hank Janssen <hjanssen@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 062519a09b7d706886d75eeb6f1691f3c0dabda9..c1ba458ca79a62deabcd2fa910e4217a4a28dcb9 100644 (file)
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -646,6 +646,7 @@ static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
        unsigned int request_size = 0;
        int i;
        struct scatterlist *sgl;
+       unsigned int sg_count = 0;
 
        DPRINT_ENTER(STORVSC_DRV);
 
@@ -730,6 +731,7 @@ 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) {
@@ -764,15 +766,16 @@ 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])));
+                               page_to_pfn(sg_page((&sgl[i])));
                }
        } else if (scsi_sglist(scmnd)) {
                /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */