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 9eaca784d2a47d47937873f9ec3b0729bea0aef7..2a4b147b0b388aa1b718eb2fa1a471bfca64e0f7 100644 (file)
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -652,6 +652,7 @@ 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);
 
@@ -736,6 +737,7 @@ 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) {
@@ -770,11 +772,12 @@ 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] =