[SCSI] libsas: fix sas_queuecommand return values

->queuecommand must return either 0, or one of the SCSI_MLQUEUE_* return
values.  Non-transient errors are indicated by setting cmd->result before
calling ->scsi_done and returning 0.  Fix libsas to adhere to this calling
convention.  Note that the DID_ERROR for returns from the low-level driver
might not be correct for all cases, but it's the best we can do with
the current layering in libsas.  I also suspect that the pre-existing
handling of -SAS_QUEUE_FULL should really be SCSI_MLQUEUE_HOST_BUSY, but
I'll leave that for a separate change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 9dd1e9eda19b..d625577ed152 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -207,7 +207,7 @@ int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 
         task = sas_create_task(cmd, dev, GFP_ATOMIC);
         if (!task)
-                return -ENOMEM;
+                return SCSI_MLQUEUE_HOST_BUSY;
 
         /* Queue up, Direct Mode or Task Collector Mode. */
         if (sas_ha->lldd_max_execute_num < 2)
@@ -223,9 +223,10 @@ out_free_task:
         SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
         ASSIGN_SAS_TASK(cmd, NULL);
         sas_free_task(task);
-        if (res != -SAS_QUEUE_FULL)
-                return res;
-        cmd->result = DID_SOFT_ERROR << 16; /* retry */
+        if (res == -SAS_QUEUE_FULL)
+                cmd->result = DID_SOFT_ERROR << 16; /* retry */
+        else
+                cmd->result = DID_ERROR << 16;
 out_done:
         cmd->scsi_done(cmd);
         return 0;