On Sat, Oct 27, 2018 at 08:12:40PM +1100, Dave Chinner wrote: > > @@ -131,7 +132,8 @@ There is not enough space on the target filesystem to complete the copy. > > .B EXDEV > > The files referred to by > > .IR file_in " and " file_out > > -are not on the same mounted filesystem. > > +are not on the same mounted filesystem when the kernel does not support > > +cross device file copy. > > Kernel can support cross device file copy, the filesystem may not. > > EXDEV > One of the files specified by file_in and file_out are on a > filesystem that does not support cross device copies. I mentioned this in my last review, and Olga pointed out that one of the changes in this patch means the kernel will do the copy using do_splice_direct if the filesystem doesn't support cross-device copying. We should keep this error documented for those on old kernels, but the kernel will never return -EXDEV any more.