scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling

stable inclusion
from stable-5.10.24
commit 79b4fdd8b4cfd88e0314b368bd911a732161c944
bugzilla: 51348

--------------------------------

[ Upstream commit d28d48c6 ]

If iscsi_prep_scsi_cmd_pdu() fails we try to add it back to the cmdqueue,
but we leave it partially setup. We don't have functions that can undo the
pdu and init task setup. We only have cleanup_task which can clean up both
parts. So this has us just fail the cmd and go through the standard cleanup
routine and then have the SCSI midlayer retry it like is done when it fails
in the queuecommand path.

Link: https://lore.kernel.org/r/20210207044608.27585-2-michael.christie@oracle.comReviewed-by: NLee Duncan <lduncan@suse.com>
Signed-off-by: NMike Christie <michael.christie@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/scsi/libiscsi.c

@@ -1532,14 +1532,9 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
 		}
 		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
 		if (rc) {
-			if (rc == -ENOMEM || rc == -EACCES) {
-				spin_lock_bh(&conn->taskqueuelock);
-				list_add_tail(&conn->task->running,
-					      &conn->cmdqueue);
-				conn->task = NULL;
-				spin_unlock_bh(&conn->taskqueuelock);
-				goto done;
-			} else
+			if (rc == -ENOMEM || rc == -EACCES)
+				fail_scsi_task(conn->task, DID_IMM_RETRY);
+			else
 				fail_scsi_task(conn->task, DID_ABORT);
 			spin_lock_bh(&conn->taskqueuelock);
 			continue;