From 486a81f387bb59b2fbbc6aff7b41adbe1621394e Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 6 Jun 2019 21:18:11 -0700 Subject: 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. --- lib/copy-file-range.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 lib/copy-file-range.c (limited to 'lib/copy-file-range.c') diff --git a/lib/copy-file-range.c b/lib/copy-file-range.c new file mode 100644 index 00000000000..39b5efbc1cc --- /dev/null +++ b/lib/copy-file-range.c @@ -0,0 +1,33 @@ +/* Stub for copy_file_range + Copyright 2019 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include + +#include + +#include + +ssize_t +copy_file_range (int infd, off_t *pinoff, + int outfd, off_t *poutoff, + size_t length, unsigned int flags) +{ + /* There is little need to emulate copy_file_range with read+write, + since programs that use copy_file_range must fall back on + read+write anyway. */ + errno = ENOSYS; + return -1; +} -- cgit v1.2.3