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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 060da9e08570eb11c71eb76ed0578a03559fe819..5504e19d17b6279b2545af9ccedc6b8396fe740e 100644 (file)
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -644,6 +644,7 @@ 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);
 
@@ -728,6 +729,7 @@ 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) {
@@ -762,11 +764,12 @@ 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] =