Inconsistent behavior when uploading to external storage root vs sub directory

[st3iny]

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Steps to reproduce

Preparation (one time)

1. Configure a file access rule to block uploads above 5 Mb
2. Ensure that chunked upload is enabled: occ config:app:delete files max_chunk_size
3. Add an external S3 storage.
4. Create a sub directory inside the external storage.

Case 1 (correct)

1. Upload a big file directly to the external storage's root folder.
2. Observe that the upload is blocked after all chunks were uploaded (error on assembly).

Case 2 (broken)

1. Upload a big file to the sub directory inside the external store.
2. Observe that the upload is blocked immediately when starting the first chunk.

Expected behavior

Case 1 is behaving as expected. Case 2 is not behaving as expected. The upload should be blocked after assembly in both cases.

Actual behavior

The upload is blocked immediately in case 2 instead of postponing the check until the whole file is available like in case 1.

Server configuration

Web server: Apache (Content-Length fix is applied)

PHP version: 8.1

Nextcloud version: master

[nickvergessen]

Case 1 (correct) Case 2 (broken)

Not sure about that. As soon as we know that the upload will be blocked, we should block it.

[st3iny]

True, but now I'm really confused. Weren't the checks delayed on purpose to prevent early scans on incomplete files? Because some checks might yield false positives when run on chunks instead of the complete file.

So I'd expect consistent behavior of waiting until all chunks are uploaded for all cases. Regardless of the file is being uploaded to /my-ext-storage or /my-ext-storage/foobar/.

See https://github.com/nextcloud/files_accesscontrol/pull/330