Set/update SPDX and Copyright statements

[igaw]

Update and/or set the SPDX tag and, where possible, also the copyright statement.

I've used reuse to identify files that are missing the SPDX tag and copyright statements and updated them where it was clear how to do so. I asked Hannes and Martin in advance whether they were okay with changing licenses. This involves either changing GPL to LGPL or replacing Apache with GPL/LGPL. Both gave me their approval.

This work is not complete. There are still many files missing copyright statements, and it is not clear what to do in those cases. I think I could ask the original authors if they could provide them (e.g., Jeremy, Margin B., ...), but I am not sure how to proceed with all those files from Keith when he was still at Intel.

Another question I have is what to do with all the documentation (Documentation and libnvme/doc). I am not sure what the original intended license is. If I understand correctly, it may not be wise to release them under GPL or LGPL. The GNU project provides specific licenses intended for documentation.

@hreinecke
@jk-ozlabs
@martin-belanger
@keithbusch

[jk-ozlabs]

I think I could ask the original authors if they could provide them (e.g., Jeremy, Margin B., ...)

Yes, absolutely fine here. The mi*.[ch] files should have existing copyright notices (and I am fine to replace those with SPDX equivalents), but let me know whether you need additional headers/SPDX tags elsewhere too.

[igaw]

I think I could ask the original authors if they could provide them (e.g., Jeremy, Margin B., ...)

Yes, absolutely fine here. The mi*.[ch] files should have existing copyright notices (and I am fine to replace those with SPDX equivalents), but let me know whether you need additional headers/SPDX tags elsewhere too.

Apparently, all files are supposed to have a SPDX tag and and a copyright statement. I added to most of the files with the SPDX tag. The copyright statement is a bit more tricky. I'll prepare a PR with something like

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * This file is part of libnvme.
 * Copyright (c) 2026 Code Construct Pty Ltd.
 *
 * Authors: Jeremy Kerr <[email protected]>
 */

those file which you have created and no copyright statement if this is okay.