Linus Torvalds [off-list ref]:

That isn't what Askar's patch ever did.

You apparently didn't even read it.

Honestly, I think you are the one out of line here.

Askar did something I suggested years ago, and didn't remove any functionality.

It just changes vmsplice to be a copying model (one of the directions
already was). It doesn't change regular splice at all.

Pedro is talking here not about this vmsplice patch, but about
my future hypothetical patch, which will remove splice-pagecache-to-pipe.

Let me clarify, what I want to send: I will make splice-pagecache-to-pipe
be a copy. I. e. this splice direction will continue to work, but will be
possibly slower. I. e. I will do something like this (see end of this email)
(absolutely not tested), and the same thing for other filesystems,
and also I will remove resulting dead code and remove
pipe_buf_operations::confirm (it will likely become unneeded).

If Pedro sends this instead, this will be okay.

diff --git i/fs/ext2/file.c w/fs/ext2/file.c
index d9b1eb34694a..8edcc3769793 100644
--- i/fs/ext2/file.c
+++ w/fs/ext2/file.c

@@ -326,7 +326,7 @@ const struct file_operations ext2_file_operations = {
        .release        = ext2_release_file,
        .fsync          = ext2_fsync,
        .get_unmapped_area = thp_get_unmapped_area,
-       .splice_read    = filemap_splice_read,
+       .splice_read    = copy_splice_read,
        .splice_write   = iter_file_splice_write,
        .setlease       = generic_setlease,
 };

-- 
Askar Safin