tree c697fde59a1928c619044548fac30bfe3ffca31c
parent 156c5a2da4a2085250f45d65e24fabe6ed437394
author Derek McGowan <derek@mcgstyle.net> 1491747225 -0700
committer Brad Fitzpatrick <bradfitz@golang.org> 1494612632 +0000

unix: add Linux CopyFileRange syscall

Introduces the CopyFileRange syscall which first appears in Linux 4.5.
Allows copying file content between file descriptors within the kernel
without transferring data to user space. This syscall also allows the
kernel to take advantage of reflinking or other fast copy methods on
supported file systems.
http://man7.org/linux/man-pages/man2/copy_file_range.2.html

Change-Id: Id365f1e5d4d5ddf7159478e3a13084c9576ebd5c
Reviewed-on: https://go-review.googlesource.com/39992
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>