Update block size change handling for tapes, according to SCSI-2 specs

uweseimet · Oct 26, 2024 · 7112254 · 7112254
1 parent c15d7f5
commit 7112254
Show file tree

Hide file tree

Showing 4 changed files with 10 additions and 2 deletions.
diff --git a/cpp/devices/storage_device.cpp b/cpp/devices/storage_device.cpp
@@ -135,7 +135,7 @@ void StorageDevice::ModeSelect(cdb_t cdb, span<const uint8_t> buf, int length)
 {
     // PF
     if (!(cdb[1] & 0x10)) {
-        // Vendor-specific parameters (SCSI-1) are not supported.
+        // Vendor-specific parameters (all parameters in SCSI-1 are vendor-specific) are not supported.
         // Do not report an error in order to support Apple's HD SC Setup.
         return;
     }

diff --git a/cpp/devices/storage_device.h b/cpp/devices/storage_device.h
@@ -117,7 +117,7 @@ class StorageDevice : public PrimaryDevice
 
     void ModeSelect(cdb_t, span<const uint8_t>, int) override;
     pair<int, int> EvaluateBlockDescriptors(scsi_command, span<const uint8_t>, int) const;
-    int VerifyBlockSizeChange(int, bool) const;
+    virtual int VerifyBlockSizeChange(int, bool) const;
     unordered_set<uint32_t> GetBlockSizes() const;
     bool SetBlockSize(uint32_t);
 

diff --git a/cpp/devices/tape.cpp b/cpp/devices/tape.cpp
@@ -271,6 +271,12 @@ vector<uint8_t> Tape::InquiryInternal() const
     return HandleInquiry(device_type::sequential_access, true);
 }
 
+int Tape::VerifyBlockSizeChange(int requested_size, bool temporary) const
+{
+    // Special handling of block size 0 for sequential-access devices, according to the SCSI-2 specification
+    return requested_size || !temporary ? VerifyBlockSizeChange(requested_size, temporary) : 0;
+}
+
 void Tape::SetUpModePages(map<int, vector<byte>> &pages, int page, bool changeable) const
 {
     StorageDevice::SetUpModePages(pages, page, changeable);

diff --git a/cpp/devices/tape.h b/cpp/devices/tape.h
@@ -93,6 +93,8 @@ class Tape : public StorageDevice, public ScsiStreamCommands
 
     uint32_t GetByteCount() const;
 
+    int VerifyBlockSizeChange(int, bool) const override;
+
     void AddModeBlockDescriptor(map<int, vector<byte>>&) const;
     void AddMediumPartitionPage(map<int, vector<byte>>&, bool) const;
     void AddDataCompressionPage(map<int, vector<byte>>&) const;