From f2123eb7376f59aa027a92de6006b1fa9fdeb373 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dav=C3=AD=C3=B0=20Steinn=20Geirsson?= <david@dsg.is>
Date: Thu, 12 Mar 2026 20:01:25 +0000
Subject: [PATCH] fix(aten-mount): distinguish handled vs ignored SCSI commands
 in log

Add LUN field and handled/ignored status to SCSI debug log lines so
unknown opcodes (silently accepted per firmware behavior) are clearly
distinguishable from handled commands that return no data.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 crates/aten-mount/src/scsi.rs | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/crates/aten-mount/src/scsi.rs b/crates/aten-mount/src/scsi.rs
index f52c5ac..e8ba691 100644
--- a/crates/aten-mount/src/scsi.rs
+++ b/crates/aten-mount/src/scsi.rs
@@ -88,20 +88,22 @@ impl<'a> ScsiDevice<'a> {
         tag.copy_from_slice(&cbw[4..8]);
         let data_transfer_len = u32::from_le_bytes([cbw[8], cbw[9], cbw[10], cbw[11]]);
         let flags = cbw[12];
+        let lun = cbw[13];
         let cb_length = cbw[14] as usize;
         let cdb = &cbw[15..15 + cb_length];
         let dir_in = flags & 0x80 != 0;
 
         let t0 = Instant::now();
-        let (data, status) = self.execute_scsi(cdb, data_transfer_len);
+        let (data, status, handled) = self.execute_scsi(cdb, data_transfer_len);
         let elapsed = t0.elapsed();
         let actual_len = data.len() as u32;
 
         let opcode = if cdb.is_empty() { 0xFF } else { cdb[0] };
         let status_str = if status == CSW_STATUS_PASSED { "OK" } else { "FAIL" };
+        let handled_str = if handled { "handled" } else { "ignored" };
         debug!(
-            "SCSI ep=0x{ep:02x} {name} (0x{opcode:02x}) tag={tag:02x?} xfer_len={data_transfer_len} \
-             resp_len={actual_len} status={status_str} elapsed={elapsed:?}",
+            "SCSI ep=0x{ep:02x} lun={lun} {name} (0x{opcode:02x}) tag={tag:02x?} xfer_len={data_transfer_len} \
+             resp_len={actual_len} status={status_str} {handled_str} elapsed={elapsed:?}",
             name = scsi_opcode_name(opcode),
         );
 
@@ -114,12 +116,14 @@ impl<'a> ScsiDevice<'a> {
         resp
     }
 
-    fn execute_scsi(&mut self, cdb: &[u8], _transfer_len: u32) -> (Vec<u8>, u8) {
+    /// Returns (data, status, handled). `handled` is false for unknown opcodes
+    /// that we silently accept per firmware behavior.
+    fn execute_scsi(&mut self, cdb: &[u8], _transfer_len: u32) -> (Vec<u8>, u8, bool) {
         if cdb.is_empty() {
             self.set_sense(SENSE_ILLEGAL_REQUEST, 0x20, 0x00);
-            return (vec![], CSW_STATUS_FAILED);
+            return (vec![], CSW_STATUS_FAILED, true);
         }
-        match cdb[0] {
+        let result = match cdb[0] {
             SCSI_TEST_UNIT_READY => self.cmd_test_unit_ready(),
             SCSI_REQUEST_SENSE => self.cmd_request_sense(cdb),
             SCSI_INQUIRY => self.cmd_inquiry(cdb),
@@ -136,10 +140,10 @@ impl<'a> ScsiDevice<'a> {
             SCSI_READ_TRACK_INFORMATION => self.cmd_read_track_information(cdb),
             SCSI_MODE_SENSE_10 => self.cmd_mode_sense_10(cdb),
             _ => {
-                warn!("unsupported SCSI opcode 0x{:02x}", cdb[0]);
-                (vec![], CSW_STATUS_PASSED)
+                return (vec![], CSW_STATUS_PASSED, false);
             }
-        }
+        };
+        (result.0, result.1, true)
     }
 
     fn cmd_test_unit_ready(&mut self) -> (Vec<u8>, u8) {
@@ -582,10 +586,10 @@ mod tests {
     #[test]
     fn test_unknown_opcode() {
         let mut dev = new_test_device();
-        let (data, status) = dev.execute_scsi(&[0xFF], 0);
-        // Firmware behavior: unknown opcodes return no data, status PASS, no error sense
+        let (data, status, handled) = dev.execute_scsi(&[0xFF], 0);
         assert_eq!(status, CSW_STATUS_PASSED);
         assert!(data.is_empty());
+        assert!(!handled);
     }
 
     #[test]