On 4/21/21 11:30 PM, Bart Van Assche wrote:
On 4/21/21 10:47 AM, Hannes Reinecke wrote:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c532f9390ae3..2d9b533ef1ec 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -245,20 +245,23 @@ int __scsi_execute(struct scsi_device *sdev,
const unsigned char *cmd,
{
struct request *req;
struct scsi_request *rq;
- int ret = DRIVER_ERROR << 24;
+ int ret;
req = blk_get_request(sdev->request_queue,
data_direction == DMA_TO_DEVICE ?
REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
rq_flags & RQF_PM ? BLK_MQ_REQ_PM : 0);
if (IS_ERR(req))
- return ret;
- rq = scsi_req(req);
+ return PTR_ERR(req);
- if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
- buffer, bufflen, GFP_NOIO))
- goto out;
+ rq = scsi_req(req);
+ if (bufflen) {
+ ret = blk_rq_map_kern(sdev->request_queue, req,
+ buffer, bufflen, GFP_NOIO);
+ if (ret)
+ goto out;
+ }
rq->cmd_len = COMMAND_SIZE(cmd[0]);
memcpy(rq->cmd, cmd, rq->cmd_len);
rq->retries = retries;
Please mention in the patch description that this change involves a user
space ABI change. My understanding is that the current behavior of the
IOC_PR_* ioctls is as follows:
* A value <= 0 is returned for NVMe where 0 represents success and a
negative value represents failure.
* A value >= 0 is returned for SCSI where 0 represents success and a
positive value is a four-byte SCSI status code.
This patch changes the behavior for SCSI from returning a value >= 0
into returning a value that can be negative, zero or positive where only
the return value 0 represents success.
See also sd_pr_command() in drivers/scsi/sd.c.
As indicated: the description for __scsi_execute() explicitly states
that a negative return value is allowed here.
And all functions calling sd_pr_command() might even now return a
negative error value, so userspace _must_ be prepared to handle it.
So while we're changing the error we return, the actual impact to
userspace should be pretty neglible as either error value indicates
a non-retryable failure.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
