Christoph Hellwig <hch@xxxxxx> wrote: > default_file_splice_write is the last piece of generic code that uses > set_fs to make the uaccess routines operate on kernel pointers. It > implements a "fallback loop" for splicing from files that do not actually > provide a proper splice_read method. The usual file systems and other > high bandwith instances all provide a ->splice_read, so this just removes > support for various device drivers and procfs/debugfs files. If splice > support for any of those turns out to be important it can be added back > by switching them to the iter ops and using generic_file_splice_read. Hmmm... this causes the copy_file_range() syscall to fail with EINVAL in some places where before it used to work. For my part, it causes the generic/112 xfstest to fail with afs, but there may be other places. Is this a regression we need to fix in the VFS core? Or is it something we need to fix in xfstests and assume userspace will fallback to doing it itself? David
