sys_copy_file_range tests

Hi Anna,

I recently looked into allowing sys_copy_file_range to use the clone_file_range operation so that file systems don't have to support two methods if they only support clone-like features, and one thing I noticed is that unlike for clone there are no tests for clone_file_range in xfstests, and I couldn't find a testsuite anywhere else either. Do you have any good tests available to verify the implementation?

Hi Christoph,

Sadly, I don't have very good tests and I was mostly using the example program from the man page under various filesystems and setups. At LPC, Darrick made it sound like he was going to work on adding vfs_copy_file_range() tests to xfstests but that probably turned into the reflink/dedupe ioctl tests.

I can try to find time to write something for xfstests if that would be useful!

Anna

Yes, Darrick wrote a lot of clone tests. Some of the aren't applicable to a pure copy, but I looking over them anc checking what should apply would be very useful!