From hjanssen@sailtheuniverse.com Thu Sep 2 13:06:54 2010 Message-ID: <4C7E9721.2050405@sailtheuniverse.com> Date: Wed, 01 Sep 2010 11:10:41 -0700 From: Hank Janssen To: hjanssen@microsoft.com, gregkh@suse.de, devel@driverdev.osuosl.org, virtualization@lists.osdl.org, linux-kernel@vger.kernel.org, Haiyang Zhang Cc: Joe Perches Subject: staging: hv: Fixed lockup problem with bounce_buffer scatter list From: Hank Janssen 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 Signed-off-by: Haiyang Zhang Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/staging/hv/storvsc_drv.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/staging/hv/storvsc_drv.c +++ b/drivers/staging/hv/storvsc_drv.c @@ -615,6 +615,7 @@ static int storvsc_queuecommand(struct s unsigned int request_size = 0; int i; struct scatterlist *sgl; + unsigned int sg_count = 0; DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d " "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction, @@ -697,6 +698,7 @@ static int storvsc_queuecommand(struct s 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) { @@ -731,15 +733,16 @@ static int storvsc_queuecommand(struct s 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); */