dkms: Source copy changes #538

[ian-abbott]

The "Use cp's -T option instead of wildcards when copying source directory" commit implements #538 to copy dot-files. Since dkms is already using the -a option, I thought it would be fine to use the -T option supported by GNU coreutils cp and BusyBox cp.

The "Preserve timestamps, file modes, and ownership when copying source directory" additionally uses cp's -p option, mostly to preserve the timestamps. It may help in cases where the source directory contains generated sources that should not need rebuilding.

[anbe42]

When thinking about copying files (not only source, but also modules), would it be a good idea to add --reflink=auto? E.g. the Nvidia modules contain some large blobs in the source, creating large modules. --reflink=auto could save some disk space on certain file systems (btrfs, xfs).

[ian-abbott]

When thinking about copying files (not only source, but also modules), would it be a good idea to add --reflink=auto? E.g. the Nvidia modules contain some large blobs in the source, creating large modules. --reflink=auto could save some disk space on certain file systems (btrfs, xfs).

That won't work with BusyBox cp. Is that a problem?

[scaronni]

Of all the distributions that are part of the tests, none uses busybox, so I think it's safe to add.

[anbe42]

OK, I'll try to make a PR for that. Not checking for the option being supported right now, but if it turns out to be problematic, we can add such a test later.