Use copy_file_range to copy files

The copy_file_range syscall (introduced in Linux kernel
version 4.5) can copy files more efficiently via server-side
copy etc.
* admin/merge-gnulib (GNULIB_MODULES): Add copy-file-range.
* lib/copy-file-range.c, m4/copy-file-range.m4:
New files, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* src/fileio.c (Fcopy_file): Try copy_file_range first,
falling back on read+write only if copy_file_range failed or
if the input is empty and so could be a /proc file.

1 files changed, 1 insertions, 1 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 4a69310d83c..c2d9291b843 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -27,7 +27,7 @@ GNULIB_URL=git://git.savannah.gnu.org/gnulib.git
 
 GNULIB_MODULES='
   alloca-opt binary-io byteswap c-ctype c-strcase
-  careadlinkat close-stream
+  careadlinkat close-stream copy-file-range
   count-leading-zeros count-one-bits count-trailing-zeros
   crypto/md5-buffer crypto/sha1-buffer crypto/sha256-buffer crypto/sha512-buffer
   d-type diffseq dosname dtoastr dtotimespec dup2