[Info-mtools] Inconsistent results between kernel vfat and mtools

[Alexander Huemer]

Hi

I am observing inconsistent results between the kernel vfat 
implementation and mtools.
The image file I am using is [1].
Here is a simple procedure that shows what I am experiencing.

Download the image. For simplicity that'll be called 'image.img' below.

mkdir -p ~/tmp/unpack
cd ~/tmp/unpack
mcopy -a ~/image.img -a :: .
sudo mount -t vfat ~/image.img /mnt
diff -u <(md5sum *) <(cd /mnt; md5sum *)

This is the result I am getting:

--- /dev/fd/63  2023-11-21 07:21:10.930270864 +0000
+++ /dev/fd/62  2023-11-21 07:21:10.930270864 +0000
@@ -1,7 +1,7 @@
-04ab6b3bd6f6689fe102a3531d15e8b1  003290.DSL
-50bb89afd3ddb2d7fe62946ee0d780f3  013179.dsl
-14c3e2c6c7c69d69c60e8a43b9c11ae1  023193.dsl
+b16167d015a5a427088eb0200a5ba051  003290.DSL
+00cd9c5a6948e029b310615b0fb074c2  013179.dsl
+b42bd0a7f6cf5a81da57a6008436e5fa  023193.dsl
 fe80900bee88c24fa11089a9ababcf5e  CSCMCNME.CMD
-9c21964c22e263063f638630e66560eb  MAINTRK.DIA
+c94fc15f7efd09966c8bbc7ced0bab9d  MAINTRK.DIA
 e07b8d18af7fe075c74a220d3a7cda30  MRNLEV.ECN
 428978ce5c2775926a4a1743b7af602e  VOLUME.LAB

I believe that the results yielded by vfat are correct and the results 
yielded by mtools are incorrect.

Does the image file have some unusual properties that push mtools to 
undesired behavior? User error? 

Thanks,
-Alex

[1] 
https://bitsavers.org/bits/IBM/3174/IBM_3174_DSL_FC9021_N52.0/IBM_3174_DSL_FC9021_N52.0.img