Strange openMSX DirAsDisk issue.

By Huey

Prophet (2687)

Huey's picture

04-01-2022, 17:38

I have some issues in TriloTracker where saved songs sometimes are corrupted.
It seems like there are old and new blocks of data in the file that is overwritten.
The strange thing is that I can only reproduce the issue on openMSX when DirAsDisk is used.

The directory is not too big. It contains aprox. 300kb. And it happens with this specific file. Time after time. Even with other contents in the directory.

The scenario is:
Load ALESTEGG.TMU and save as new file ALESTETT.TMU. No problem
Load ALESTEGG.TMU and save (overwrite). Problem. Pieces of old data and new data are mixed.

The file is saved in smaller sequential writes as I have to compress the data on the fly. The blocks of data, that are wrong, do not allign with save actions. So it is almost not possible that the wrong data is written.

This issue only happens with DirAsDisk in openMSX.
It does works in these situations without issues:
- OpenMSX on a HDD image
- Emulicious as DirAsDisk
- Real MSX on an MFR and floppy.

Does anyone have an idea why this happens?
Are there other cases known where this happens?

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By sdsnatcher73

Prophet (3413)

sdsnatcher73's picture

04-01-2022, 18:48

Many issues have been reported with dirasdisk feature but it was always difficult to find a good reproducible scenario. If you have a reproducible scenario (sounds like you do) I suggest you create an issue on their github repo. Include a zip of the files you start with in the directory, include all the steps to reproduce the issue and the expected result as well as the actual result.

By Huey

Prophet (2687)

Huey's picture

04-01-2022, 19:56

Ah thanks!
I'll try to make an example + reproduction instruction and will submit a bug on github.

By sdsnatcher73

Prophet (3413)

sdsnatcher73's picture

04-01-2022, 19:59

Great! Would be good if the issue could be fixed (I have had strange things happen with DirAsDisk as well and stopped using it generated). But I fully understand the developers that without a good reproducible description it is extremely difficult to troubleshoot. So as an openMSX user, thanks from me!

By Huey

Prophet (2687)

Huey's picture

04-01-2022, 20:13

Submitted the issue on GitHub..

Hope they are able to fix it. Would be a shame if I have to add a warning to the startup of TT.

By wouter_

Champion (485)

wouter_'s picture

04-01-2022, 20:16

A recipe to reproduce would be great! Thanks.
Several weeks ago I did find (and fixed) a bug in the dir-as-disk code. So there is a small(?) chance the problem is already gone in the latest development snapshots.

By Huey

Prophet (2687)

Huey's picture

05-01-2022, 17:18

With the latest development build the issue is solved!!!!!!! Running Naked in a Field of Flowers Running Naked in a Field of Flowers Running Naked in a Field of Flowers Running Naked in a Field of Flowers Running Naked in a Field of Flowers Running Naked in a Field of Flowers