On 2021/12/27 3:49, Michael Kelley (LINUX) wrote:

From: YueHaibing <redacted> Sent: Friday, December 24, 2021 4:02 AM

quoted

The unsigned variable sg_count is being assigned a return value
from the call to scsi_dma_map() that can return -ENOMEM.

Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for storvsc driver")
Signed-off-by: YueHaibing <redacted>

Good catch!  But I wonder if a simpler fix is to just remove the "unsigned"
from the declaration of sg_count.  Then we don't need to add the
sg_cnt local variable.  A little less complexity is almost always better. :-)

Ok， will respine

Michael

quoted

---
 drivers/scsi/storvsc_drv.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index ae293600d799..072c752a8c36 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c

@@ -1837,7 +1837,7 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 		unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
 		struct scatterlist *sg;
 		unsigned long hvpfn, hvpfns_to_add;
-		int j, i = 0;
+		int sg_cnt, j, i = 0;

 		if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {

@@ -1851,11 +1851,11 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 		payload->range.len = length;
 		payload->range.offset = offset_in_hvpg;

-		sg_count = scsi_dma_map(scmnd);
-		if (sg_count < 0)
+		sg_cnt = scsi_dma_map(scmnd);
+		if (sg_cnt < 0)
 			return SCSI_MLQUEUE_DEVICE_BUSY;

-		for_each_sg(sgl, sg, sg_count, j) {
+		for_each_sg(sgl, sg, sg_cnt, j) {
 			/*
 			 * Init values for the current sgl entry. hvpfns_to_add
 			 * is in units of Hyper-V size pages. Handling the
--

2.17.1

.