3 ms·

It sounds wrong to depend on the file length for correctness even on physical file systems. What if the file length shrinks during the copy? You need to just ke

• cpuguy83 6y ago
  That's assuming you want to copy the the whole thing. And even if you do want to do that, this is what you do with copy_file_range as well, just that in many cases you can do it with a single call instead of multiple read/write calls in addition to being able to take advantage of performance optimizations (such as reflinking).
  • dataflow 6y ago
    > That's assuming you want to copy the the whole thing Right, but if you don't, then you definitely don't need to query the file length in the first place...