Hi folks, Since clone/dedupe/copy_file_range support was added to fsx, I've found several data corruptions and issues with these functions. The patchset addresses some of the issues I've found, including a problem with the FUA optimisation that I found by inspection when looking at this code. Several of the problems stem from do_splice_direct() and how it behaves on files opened O_DIRECT. I'm pretty sure this has never been tested on XFS because it just doesn't work and has stale data exposure problems. And it's so slow it's not funny because it can only shuffle 16 pages at a time through the splice pipe, which means synchronous 64k IO for large data movement. do_splice_direct() is a horrible data copying primitive. The first 3 patches are data integrity/corruption fixes for the iomap code, patch 4 increases the do_splice_direct() pipe size to the maximum allowed without privilege to improve performance, and the last patch fixes an error reporting inconsistency between dedeupe and the documented errors in the man page. Cheers, Dave.
