[Qemu-devel] [PATCH 1/2] iscsi: Translate scsi sense into error code

[Fam Zheng <famz@redhat.com>]

Previously we return -EIO blindly when anything goes wrong. Add a helper
function to parse sense fields and try to make the return code more
meaningful.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/iscsi.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 93f1ee4..f3e20ae 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -84,6 +84,7 @@ typedef struct IscsiTask {
     IscsiLun *iscsilun;
     QEMUTimer retry_timer;
     bool force_next_flush;
+    int err_code;
 } IscsiTask;
 
 typedef struct IscsiAIOCB {
@@ -182,6 +183,58 @@ static inline unsigned exp_random(double mean)
 #define QEMU_SCSI_STATUS_TIMEOUT        SCSI_STATUS_TIMEOUT
 #endif
 
+static int iscsi_translate_sense(struct scsi_sense *sense)
+{
+    int ret = 0;
+
+    switch (sense->key) {
+    case SCSI_SENSE_NO_SENSE:
+        return 0;
+        break;
+    case SCSI_SENSE_NOT_READY:
+        return -EBUSY;
+        break;
+    case SCSI_SENSE_DATA_PROTECTION:
+        return -EACCES;
+        break;
+    case SCSI_SENSE_COMMAND_ABORTED:
+        return -ECANCELED;
+        break;
+    case SCSI_SENSE_ILLEGAL_REQUEST:
+        /* Parse ASCQ */
+        break;
+    default:
+        return -EIO;
+        break;
+    }
+    switch (sense->ascq) {
+    case SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR:
+    case SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE:
+    case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB:
+    case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST:
+        ret = -EINVAL;
+        break;
+    case SCSI_SENSE_ASCQ_LBA_OUT_OF_RANGE:
+        ret = -ERANGE;
+        break;
+    case SCSI_SENSE_ASCQ_LOGICAL_UNIT_NOT_SUPPORTED:
+        ret = -ENOTSUP;
+        break;
+    case SCSI_SENSE_ASCQ_WRITE_PROTECTED:
+        ret = -EACCES;
+        break;
+    case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT:
+    case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_CLOSED:
+    case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_OPEN:
+        ret = -ENOMEDIUM;
+        break;
+    default:
+        ret = -EIO;
+        break;
+    }
+    return ret;
+}
+
 static void
 iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
                         void *command_data, void *opaque)
@@ -226,6 +279,7 @@ iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
                 return;
             }
         }
+        iTask->err_code = iscsi_translate_sense(&task->sense);
         error_report("iSCSI Failure: %s", iscsi_get_error(iscsi));
     } else {
         iTask->iscsilun->force_next_flush |= iTask->force_next_flush;
@@ -455,7 +509,7 @@ retry:
     }
 
     if (iTask.status != SCSI_STATUS_GOOD) {
-        return -EIO;
+        return iTask.err_code;
     }
 
     iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors);
-- 
2.4.3