qemu-pr-helper: miscellaneous fixes

1) Return a generic sense if TEST UNIT READY does not provide one;

2) Fix two mistakes in copying from the spec.

Cc: qemu-stable@nongnu.org
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/scsi/utils.h

@@ -76,7 +76,11 @@ extern const struct SCSISense sense_code_LUN_FAILURE;
 extern const struct SCSISense sense_code_LUN_COMM_FAILURE;
 /* Command aborted, Overlapped Commands Attempted */
 extern const struct SCSISense sense_code_OVERLAPPED_COMMANDS;
-/* LUN not ready, Capacity data has changed */
+/* Medium error, Unrecovered read error */
+extern const struct SCSISense sense_code_READ_ERROR;
+/* LUN not ready, Cause not reportable */
+extern const struct SCSISense sense_code_NOT_READY;
+/* Unit attention, Capacity data has changed */
 extern const struct SCSISense sense_code_CAPACITY_CHANGED;
 /* Unit attention, SCSI bus reset */
 extern const struct SCSISense sense_code_SCSI_BUS_RESET;

scsi/qemu-pr-helper.c

@@ -314,6 +314,22 @@ static int is_mpath(int fd)
     return !strncmp(tgt->target_type, "multipath", DM_MAX_TYPE_NAME);
 }
 
+static SCSISense mpath_generic_sense(int r)
+{
+    switch (r) {
+    case MPATH_PR_SENSE_NOT_READY:
+         return SENSE_CODE(NOT_READY);
+    case MPATH_PR_SENSE_MEDIUM_ERROR:
+         return SENSE_CODE(READ_ERROR);
+    case MPATH_PR_SENSE_HARDWARE_ERROR:
+         return SENSE_CODE(TARGET_FAILURE);
+    case MPATH_PR_SENSE_ABORTED_COMMAND:
+         return SENSE_CODE(IO_ERROR);
+    default:
+         abort();
+    }
+}
+
 static int mpath_reconstruct_sense(int fd, int r, uint8_t *sense)
 {
     switch (r) {
@@ -329,7 +345,13 @@ static int mpath_reconstruct_sense(int fd, int r, uint8_t *sense)
              */
             uint8_t cdb[6] = { TEST_UNIT_READY };
             int sz = 0;
-            return do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE);
+            int r = do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE);
+
+            if (r != GOOD) {
+                return r;
+            }
+            scsi_build_sense(sense, mpath_generic_sense(r));
+            return CHECK_CONDITION;
         }
 
     case MPATH_PR_SENSE_UNIT_ATTENTION:
@@ -449,7 +471,7 @@ static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense,
     memset(&paramp, 0, sizeof(paramp));
     memcpy(&paramp.key, &param[0], 8);
     memcpy(&paramp.sa_key, &param[8], 8);
-    paramp.sa_flags = param[10];
+    paramp.sa_flags = param[20];
     if (sz > PR_OUT_FIXED_PARAM_SIZE) {
         size_t transportid_len;
         int i, j;
@@ -478,8 +500,8 @@ static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense,
                 j += offsetof(struct transportid, n_port_name[8]);
                 i += 24;
                 break;
-            case 3:
+            case 5:
-            case 0x43:
+            case 0x45:
                 /* iSCSI transport.  */
                 len = lduw_be_p(&param[i + 2]);
                 if (len > 252 || (len & 3) || i + len + 4 > transportid_len) {

scsi/utils.c

@@ -211,6 +211,16 @@ const struct SCSISense sense_code_LUN_COMM_FAILURE = {
     .key = ABORTED_COMMAND, .asc = 0x08, .ascq = 0x00
 };
 
+/* Medium Error, Unrecovered read error */
+const struct SCSISense sense_code_READ_ERROR = {
+    .key = MEDIUM_ERROR, .asc = 0x11, .ascq = 0x00
+};
+
+/* Not ready, Cause not reportable */
+const struct SCSISense sense_code_NOT_READY = {
+    .key = NOT_READY, .asc = 0x04, .ascq = 0x00
+};
+
 /* Unit attention, Capacity data has changed */
 const struct SCSISense sense_code_CAPACITY_CHANGED = {
     .key = UNIT_ATTENTION, .asc = 0x2a, .ascq = 0x09